This study investigates the fabrication and characterization of microwaves assisted Bismuth-doped graphitic carbon nitride (Bi@g-C3N4)composite into TiO2 as a photoanode material, for dye-sensitized solar cells (DSSC). The effect of Bi@g-C3N4/TiO2 was evaluated through photovoltaic performance measurements, revealing significant increases in power conversion efficiency (PCE) from 2.70% for Pure TiO2 to 9.22% for Bi@g-C3N4/TiO2, which are sensitized with anthocyanin at acidic medium. This improvement areattributed to improved light harvesting and reduced charge recombination. Additionally, the fill factor was improved from 0.46 to 0.50, respectively. The structural and compositional properties of Bi@g-C3N4/TiO2 were characterized using FTIR, XRD, SEM, EDX, and DRS. For a better understanding of the practical work, theoretical studies were performed for Bi@g-C₃N₄ as a photoanode for DSSCs. Density functional theory (DFT) calculations demonstrate that bismuth doping reduces the band gap, which introduces extra states, hence, enhances the density of states near the Fermi level, leading to more visible-light absorption and charge carrier density. As for optical properties, specifically dielectric function and conductivity spectra show better polarization effect and electron mobility. The molecular orbital study of Anthocyanin&Bi@g-C₃N₄ also shows more energy level order, which facilitates electron injection and charge separation. SEM and EDX results show the good dispersion of porous nanoparticles with homogeneous composition, where 7.36% Bi by weight is present, indicating successful doping and composite formation. The efficiency is also improved in acidic medium (pH1), showing improved charge separation and reduced recombination, while at higher pH values, lower efficiencies are observed (1.04% at pH 7 and 0.54% at pH 12). Furthermore, DFT and TD-DFT calculations show that Bi doping facilitates electron injection, recombination barriers are reduced, and absorption peaks are also shifted from 456 nm to 491 nm, which improve light harvesting and efficiency. Finally, the synergistic increase in light harvesting, charge generation, and transport makes Bi@g-C₃N₄ a good candidate for high-efficiency photovoltaic applications.

This research studies the purification of montmorillonite from natural Iraqi bentonite clay (NIBC). Montmorillonite was characterized using XRD, SEM-EDX, TEM, FTIR, DRS, and UV–vis spectrophotometry. The purified montmorillonite is then employed as an adsorbent and the catalytic degradation of organic aqueous pollutants, specifically Methylene Blue (MB). The results show that the selected organic pollutant MB was removed using both adsorption and catalytic degradation. Different isotherms were applied, including Langmuir, Freundlich, and Temkin. Kinetic and thermodynamics were also studied; MB adsorption followed the pseudo-second-order model, and the heat of adsorption for MB was (ΔH° = −19.1 kJ/mol), indicating a physical process. The catalytic degradation was examined utilizing different redox agents, including H2O2, NaBH4, and KBrO3. Box-Behnken Design (BBD) was applied to study the catalytic degradation; hence, ANOVA analysis shows the significant role of H2O2 concentration (p = 0.0141), and the synergistic effects were observed for H2O2-NaBH4 (p = 0.0082) and NaBH4-KBrO3 (p = 0.0012) interactions. Furthermore, Density Functional Theory (DFT), DFTB+, and molecular dynamic (MD) were applied to get a better understanding of the molecular level. Theoretical calculations, including HOMO–LUMO analysis, electron density difference (EDD), global reactivity descriptors, and Density of States (DOS), were all employed. The montmorillonite exhibits a narrow HOMO–LUMO gap (0.05 eV), high electrophilicity (ω = 18.71), and low hardness (η = 0.0242), indicating excellent electron-transfer capability. DOS shows the availability of Fe-d orbitals and Si-p orbitals near the Fermi level, which facilitate the oxidation and reduction process. These results could provide a mechanistic insight into montmorillonite catalytic performance in catalytic environmental remediation.

Boron nitride (BN) doped with carbon atoms is a new metal-free nanoparticle that has various applications, including photocatalysis and as an adsorbent in adsorption processes. Regarding application as a photocatalyst, in fact, the band gap energy of BN is roughly 5.2 eV, which is very high if compared with metal-based photocatalysts such as TiO₂, ZnO, etc. However, composite and doped BN give excellent activity in photodegradation with gap energy ranging between 1.5 and 2.5 eV. As it is a porous material, it gives extra efficiency to photocatalysis, which provides a larger surface area. With respect to adsorption, the addition of functional groups to BN edges makes the BN nanoparticle selective, which provides porosity, increase active sites and a large surface area, which varies from 100 to 950 m² g⁻¹. Additionally, carbon-doped boron nitride can be used in electrocatalysis processes like carbon dioxide reduction and ammonia synthesis. All in all, carbon-doped boron nitride (BN) shows potential environmental remediation catalyst. Its enhanced photocatalytic activity, large surface area and improved visible light absorption enable BN to degrade pollutants in water medium for environmental clean-up applications. The preparation condition marginally effects the structural, optical and electronic more specifically band edges position of carbon doped BN.

The continuous discharge of hazardous synthetic dyes into aquatic environments as a result of rapid industrialization poses a serious threat to both environmental and human health. This review aims to provide a comprehensive and up to date evaluation of adsorption techniques for dye removal from wastewater, with a focus on both conventional and emerging adsorbent materials. The review examines and compares natural materials, such as clays, zeolites, charcoal, and agricultural wastes, as well as engineered and nano scale materials, including carbon nanotubes, graphene, metal organic frameworks, and nanocomposites, for wastewater decolorization. This study presents a critical analysis of published studies from 2018 to 2025, focusing on the performance of various adsorbents under key operational parameters such as pH, temperature, contact time, and adsorbent dosage. The dominant adsorption mechanisms, including electrostatic attraction, ion exchange, and surface complexation, are systematically discussed. Special attention is given to the role of nanotechnology and green synthesis strategies in improving adsorption efficiency and material reusability. The review indicates that nano engineered and hybrid adsorbents generally exhibit superior adsorption performance and represent promising candidates for scalable and environmentally sustainable wastewater treatment applications. Future research should prioritize the development of cost-effective regeneration methods, evaluation using real industrial effluents, and pilot scale studies to facilitate the transition from laboratory research to industrial implementation.

This review covers recent developments in dye-sensitized solar cells, focusing on natural pigments, nanostructures in photoanodes, and modifications to electrolytes, which all relate to the enhancement of device performance. Anthocyanins, chlorophyll, and carotenoids are some natural dyes that are under investigation as alternatives to ruthenium-based synthetic dyes. However, they still have some drawbacks due to their restricted absorption spectra and low stability. Enhanced extraction methods have realized 30% gains in dye performance. The design and composition of the photoanode play a significant role in DSSC efficiency. The latest progress in doping TiO₂ with materials like silver and graphene, adding other semiconductors such as ZnO and MoS₂, has established efficiencies as high as 10.35% for DSSCs. Moreover, interface modification, especially the use of alternative electrolytes, replacing the conventional iodide/triiodide system with cobalt, copper complexes, has attained higher efficiencies up to 14.4%. However, stability in volatile solvents remains a challenge. This review considers DSSCs to become one of the practical renewable energy technologies, yet some important limitations, together with ways for future research, are emphasized.

This study introduces the synthesis, characterization, and utilization of carbon quantum dots (CQDs) from sunflower seed shells for the first time, specifically as a photoluminescence (PL) sensor for cadmium ion detection. CQDs were synthesized by a hydrothermal method. The CQDs were analyzed employing various physicochemical methods, including XRD, FTIR, TEM, UV–Vis spectroscopy, and fluorescence spectroscopy. The green-source CQDs demonstrated an average nanoscale dimension of 2.1 nm and displayed PL behavior, an emission peak at 497 nm, with a quantum yield (QY) of 33.5%. The synthesized CQDs exhibited significant selectivity for Cd2+ ion detection, with PL intensity diminishing as Cd2+ concentrations increased (1–10 μM). The detection limit was established at 0.12 μM, while the limit of quantification was set at 0.38 μM. Selectivity experiments demonstrated that the CQDs displayed a robust response to Cd2+ ions with negligible interference from other metal ions. The results indicate that the synthesized CQDs are a viable, economical, and eco-friendly material for the detection of cadmium contamination in water. Additionally, density functional theory (DFT) measurements were employed to investigate the quenching mechanism between CQDs and Cd2+ ions. The findings indicated that aldehyde groups on the CQD surface demonstrate the most robust interaction with Cd2+ ions, elucidating the fluorescence quenching mechanism.

A new, quick, economical, accurate and precise spectrophotometric method was developed for the determination of sulfanilamide in its pure form. This technique focused on the reaction of this amine as an n-donor via the charge-transfer complex formation reaction with pyromellitic dianhydride (PMDA) as a π-acceptor. The maximum absorption of sulfanilamide was at 258 nm. Beer's law was observed over the concentration range of 0.2–35 μg mL⁻¹ with a molar absorptivity value of 16 226.24 L mol⁻¹ cm⁻¹. The accuracy of the method (average recovery %) was 101.501%, and its precision (RSD %) was less than 0.6%. The nature of PMDA complexes with sulfanilamide was studied using the mole ratio method. The findings demonstrated that this complex was produced in a ratio of 1 : 1 with a stability constant of 2.49 × 10⁸ L mol⁻¹ for the amine-PMDA complex. The detection limit (LOD) was 0.0136 μg mL⁻¹, and the limit of quantification (LOQ) was 0.0412 μg mL⁻¹. DFT calculations were employed to learn more about the charge transfer mechanism. Density of states (DOS) calculations demonstrated electronic interactions near the Fermi level, in which nitrogen and sulfur orbitals from sulfanilamide act as electron donors, while the carbonyl group and aromatic system of PMDA act as electron acceptors. HOMO–LUMO analysis further confirmed this donor–acceptor mechanism.

This study investigates the fabrication and characterization of natural pigment and carbon nitride quantum dots (CNQDs) co-sensitized solar cells. The results showed that CNQDs@TiO2 significantly improved light absorption and charge transfer properties. The effects of pH and temperature were examined to assess their influence on DSSC performance. It was found that an acidic medium yields the best results, with an optimal temperature of 25 °C. Photovoltaic measurements revealed a significant efficiency improvement in DSSCs, increasing from 2.7% for anthocyanin@TiO2 to 8.6% when modified with anthocyanine & CNQDs@TiO2. In addition, the fill factor was improved from 0.46 to 0.63, respectively. The structural composition, size, morphology, and optical properties of CNQDs@TiO2 were characterized using FTIR, DRS, XRD, FESEM, EDX, and TEM analytical techniques. DFT calculations were employed to learn more about the mechanism, efficiency, and photovoltaic properties of synthesized DSSCs. The theoretical results agree with experimental data in which the anthocyanine & CNQDs @ TiO2 system is more efficient. CNQDs can be mediators, broadening the spectrum of light harvesting and providing extra bands that facilitate electron transitions.

The fast growth of industrialization and the increase in chemical use have made water pollution a serious issue that endangers both the environment and people. Pollutants in wastewater have serious environmental and health issues. This research examines the synergetic effect of a novel metal-free nanocomposite, carbon nitride quantum dots (CNQDs) anchored to NaBiO₃ photocatalyst. CNQDs@NaBiO₃ nanocomposites were successfully synthesized to harvest solar light and to remove contaminants like pesticides, pharmaceuticals, and dyes. CNQDs@NaBiO₃ was characterized utilizing available techniques, including SEM-EDX, FTIR, XRD, UV-visible, and DRS spectroscopy. The removal efficiency was assessed for methylene blue, eosin yellowish, tetracycline, and trifluralin under visible light exposure and solar light. The resulting rate constant of degradation is remarkably efficient for all molecules, and its kinetics was second-order for all: trifluralin 0.1828M/min ,tetraycline 0.2249 M/min, methylenee blue 0.1438 M/min, and eosin yellowish 0.1579M/min. It is worth mentioning that CNQDs@NaBiO₃ work at a temperature range of 15-45°C and show maximum degradation at 15°C. The trapping experiments were also conducted to determine the ROS involved in degradation and the mechanism, experimental findings indicate that all active species, h⁺, e⁻, O₂⁻•, and •OH, are involved in degradation. DFT simulation was performed to reveal details about the newly designed CNQDs@NaBiO₃ nanocomposite compared to NaBiO₃, and for this reason, optical and electronic properties were computed. Theoretical results showed that CNQDs have a synergetic effect on NaBiO₃, which provides extra bands, an extended band edge, and a broadened spectrum of light absorption that is more useful in solar light harvesting.

In the current research work, a successful NaBiO3@TiO2 nanocomposite photocatalyst was synthesised and characterised utilising SEM, XRD, FTIR, EDX, and DRS techniques. The nanocomposite showed flake-like morphology with a reduced band gap energy of 3.08 eV and extended band edges −0.61 CB and 2.47 eV for VB, which enhance its visible light absorbance and can generate all required reactive oxygen species (ROS) involved in degradation. Photocatalytic degradation was carried out under different conditions of pH, catalyst type, and light source with methylene blue as the model pollutant. A Box-Behnken Design (BBD) was utilised to investigate the effect of three significant parameters: catalyst type, pH, and light source. It was found that the light source had the most impact on photocatalytic activity, and solar light produced the highest degradation rates. The maximum degradation (~88.2%) was at neutral pH under solar light with NaBiO3@TiO2 Nanocomposite. The linear regression model was significant and provided a good fit of the experimental data. The study demonstrates that the NaBiO3@TiO2 nanocomposite is effective photocatalyst for environmental applications under sustainable and readily available solar light. The DFT calculations investigated the electronic and optical properties of NaBiO₃@TiO₂ and TiO₂ under visible and near-UV radiation. Compared to TiO₂, which has an indirect bandgap (~3 eV) with O-2p and Ti-3d-dominated states, NaBiO₃@TiO₂ exhibits a narrower effective bandgap due to Bi-6s/6p hybridisation, enhancing visible-light absorption. Optical analysis reveals that NaBiO₃@TiO₂ shows broader and stronger absorbance, a higher dielectric response, attributed to Bi3 + lone pair contributions.

The growing amount of synthetic dyes, like Congo red (CR), being released into water systems poses a serious risk to the environment and public health because they are toxic, long-lasting, and hard to treat. These colors may obstruct aquatic photosynthesis, disturb biological life cycles, and provide carcinogenic dangers to humans. This research examines the catalytic degradation of CR dye with nanostructured Iraqi bentonite clay (NIBC) as an economical and sustainable catalyst. NIBC underwent purification with glacial acetic acid to enhance its surface activity and catalytic efficacy. The experimental design employed a Box-Behnken Design (BBD) combined with Response Surface Methodology (RSM) to statistically assess and optimize the individual and interactive effects of three chemical agents—hydrogen peroxide (H₂O₂), sodium borohydride (NaBH₄), and potassium bromate (KBrO₃)—on degradation efficiency. Catalytic degradation tests were performed at neutral pH, using UV-Vis spectroscopy to assess CR content A maximum CR degradation rate of 36.9% was attained under optimum settings. Scavenger trapping studies were used to determine the predominant reactive oxygen species (ROS) involved in the degradation pathway. Results demonstrated that superoxide radicals (•O₂⁻) and hydroxyl radicals (•OH) were the principal reactive oxygen species (ROS) facilitating the degradation of CR molecules, subsequently accompanied by the participation of electrons and holes. Energy-Dispersive X-ray (EDX) and Scanning Electron Microscopy (SEM) . These results highlight the promise of chemically modified b​e​n​t​o​n​i​t​e​

Herein, spinel CoNi2O4 nanoflowers (NFs) were successfully synthesized by a two-step hydrothermal annealing process and testified to have intrinsic enzyme mimic activities. The CoNi2O4 NFs can effectively oxidize the chromogenic substrate 3, 3′, 5, 5′-tetramethylbenzidine (TMB) to ox-TMB showing catalytic behavior that follows enzyme kinetics of Michaelis-Menten equation with a low constant (Km = 0.0143 mM). Innovatively, experimental data and Density Functional Theory (DFT) calculations disclosed the stable structure and mechanism of spinal CoNi2O4NFs, which demonstrated oxidase-like activity and reactive oxygen species independence across a wide temperature range. Accordingly, a colorimetric biosensor for rapid and sensitive detection of ascorbic acid (AA) was successfully developed, displaying excellent stability, selectivity, sensitivity and low limit of detection (0.44 μM). This biosensor was applied to vitamin C capsules and fresh lemon fruit, showing favorable reproducibility and feasibility. DFT and molecular modeling (MD) calculations indicate a cobalt atom as the optimal site for catalytic conversion, while the amine group in the TMB molecule is the optimal nucleophilic attack site.

This study explores a green synthesis process of Co-Zn-Ni trimetallic oxide nanoparticles (NPs) using Cicer arietinum leaf extract based on phytochemicals within the extract that can act as both capping and reducing agents. The synthesized trimetallic nanoparticles were thoroughly characterized using SEM, TEM, EDX, XRD, FTIR, BET and TGA. The results indicated a regular spherical shape with a 25.72 nm particle size for the synthesized nanoparticles. A single elemental analysis showed nearly the same elemental ratios of O=29.1 %, Zn = 26.4 %, Co = 22.4 %, and Ni = 22.1 %. The XRD analysis verified the formation of Co-Zn-Ni trimetallic oxide NPs, mostly with amorphous structures. The FTIR spectra indicated peaks of the presence and successful formation of specific functional groups. TGA analysis evaluated the oxidative and thermal stability. The antibiofilm activity of the prepared NPs was tested against Staphylococcus aureus bacteria known to produce biofilm. The results showed stronger antibiofilm activity of the prepared nanoparticles (51.6 %) than the commonly used antibiotic ciprofloxacin (42.5 %), suggesting their potential as biofilm disruptors. A molecular docking was also applied to nanostructure and compared with the ciprofloxacin drug. The molecular docking was performed against the active pocket receptors DNA GYRASE and Surface Protein G, which may inhibit Staphylococcus aureus. The results indicated that the fabricated Co-Zn-Ni NPs can show a good binding score against proteins of DNA GYRASE and surface protein G better than the ciprofloxacin drug, with values equal to −37.694 and −42.1067 kcal/mol, respectively.

This work is aimed to synthesize nanostructured boron nitride quantum dots (BNQDs) that act as photo-catalyst under UV light irradiation. The photocatalyst is appliedto remove organic wastes via photodegradation. BNQDs were characterized using XRD, SEM-EDX, FTIR, UV-Vis and fluorescence spectrophotometry. BNQDs have the energy gap close to 3.79eV. The results show that the obtained band gap value and band edges position are higher than the value of free energy for photo degradation at conduction and valance bands, this proves that the BNQDs is thermodynamically suitable to drive super oxide and hydroxyl radical production. BNQDs is employed to eliminate different pollutants including, dyes and pharmaceuticals. Kinetic was studied as well, the result of kinatic shows that the degradation of Amlodipine and tetracycline at peak 367nm and 375nm areof the second order with a R2 value of 0.98, 0.97 respectively, and first order kinetic in case of Congo red and toluidine blue at peak 497nm, 615nm respectively with a R2 value of 0.96 for both molecules. Reactive oxygen species (ROS) trapping experiments was performed to determine the active species in photo-catalysis mechanism. Based2on experimental data we can conclude that active species h+, e−, O −• and •OH have a significant effect on degradation yield. Regarding computational simulation, the crystal and electronic structures of the BNQDs have been calculated. The lattice parameters were measured with the Perdew-Burke-Ernzerhof (PBE) functional, and the energy gap (Eg) were calculated applying hybrid functionals including (Becke-3 Parameter-Lee-Yang-Parr) B3LYP and (Heyd–Scuseria–Ernzerhof) exchange–correlation functional HSE06. B3LYP provided better results and closer to the experimental data, given that 2eV as an indirect band gap and thus, B3LYP exchange function was utilized to analyze the band structures and density of states.

Water pollution has become a major concern due to the rapid development of industrialization and rise in chemical use, which poses a great risk to humans and environment. Herein, a novel nanocomposite of metal-free boron nitride quantum dots (BNQDs) supported on graphitic carbon nitride (g-C3N4) photocatalyst (BNQDs@g-C3N4) was successfully synthesized using a facile and green approach. The prepared nanocomposite exhibited exceptional photocatalytic activity in the degradation of aqueous waste pollutants, including organic dyes and pharmaceuticals under visible light irradiation, its worth mentioning, the rate constant of tetracycline removal was 0.064 mol−.L.min−1. The experimental results indicated that the significantly boosted photocatalytic activity of the BNQDs@g-C3N4 composite proved the energy gap modulation by the construction of heterojunction between the BNQDs and g-C3N4 in s-scheme photocatalyst. Theoretical calculations were done to calculate the crystal, electronic structures, and properties of BNQDs@g-C3N4. Theoretical results showed that loading of BNQDs on g-C3N4 provides an extended band edges that are more applicable in visible light-based photocatalysis process. Additionally, it offers additional bands that facilitate the passage of electrons between the valance and conduction bands. Finally, a possible s-scheme mechanism of the charge separation improvement was proposed by analyzing the experimental results and theoretical calculations.

This article focuses on Pelargonium graveolens, a fragrant medicinal plant from the Geraniaceae family. The study examines the plant's phytochemical composition, antioxidant activity, and mineral absorptivity, with the plant being grown indoors. The study also examined the plant's ash content and antioxidant activity using a variety of techniques, and the results demonstrated that P. graveolens is effective at absorbing lead. The plant contains eight different minerals, including Cu, Mn, Co, Ni, Pb, Mg, Fe, and Ca. Statistical analysis was used to determine the level of antioxidants present, using DPPH, reducing power, and total antioxidant capacity methods. The extraction process used a mixture of water, 70% ethanol and absolute ethanol solvents in varying ratios. To conclude, the study examines Pelargonium graveolens, a fragrant medicinal plant, for its antioxidant activity and mineral absorptivity.

In this study, a novel photocatalyst, Cu&Ni@FAU Faujasite type zeolite, was successfully prepared and characterised using various techniques, including XRD, SEM-EDX, FTIR, N2 adsorption-desorption isotherm, and UV-Vis spectrophotometry. Cu&Ni@FAU enhances the photocatalytic efficiency through several mechanisms, including the photo-Fenton-like process of H2O2, the electronic capture of KBrO3, and the reducing effect of NaBH4. Response surface methodology has been applied to study the impact of H2O2, KBrO3, and NaBH4 and their interactions on the photocatalysis of tetracycline. Furthermore, the efficiency of the photocatalysts and their kinetics were assessed for four different organic molecules, and it was found that the rate constant of tetracycline degradation was 0.054 M−1min−1. It is worth mentioning, Cu&Ni@FAU is temperature stable and shows maximum degradation at 70°C. Radical trapping experiments revealed that various reactive species played a role in the photodegradation process. The results show that hydroxyl radicals (OH•) and superoxide radicals (O2-•) are the dominant species in the photocatalysis mechanism. Additionally, electrons (e-) and holes (h+) had a moderate impact as active species, since the band edges of Cu&Ni@FAU is located between 2.86 eV at valance band (VB) and −0.38 eV at conduction band (CB).. To gain deeper insights into these processes, the study used density functional theory (DFT) simulation, which allowed for the calculation of electronic and vacuum band edges. This computational approach likely provided valuable information about the fundamental processes occurring during the photocatalysis process.

To achieve the efficient removal of pharmaceutical wastes, novel photo-Fenton catalysts, iron-decorated boron nitride quantum dots (Fe@BNQDs) were prepared. Fe@BNQDs were characterized using XRD, SEM-EDX, FTIR, and UV-Vis spectrophotometry. The decoration of Fe on the surface of BNQDs enhanced the catalytic efficiency due to the photo-Fenton process. Photo-Fenton catalytic degradation of folic acid was investigated under UV and visible light. The influence of H2O2, catalyst dose, and temperature on the degradation yield of folic acid was investigated using Response Surface Methodology. Moreover, the efficiency of the photocatalysts and kinetics was investigated. Radical trapping experiments revealed that holes were the main dominant species in the photo-Fenton degradation mechanism and BNQDs played active roles because of their hole extraction ability. Additionally, active species such as e− and O2−˙ have a medium effect. The computational simulation was utilized to provide insights into this fundamental process, and for this purpose, electronic and optical properties were calculated.

In this paper, silver-loaded phosphorous and carbon co-doped boron nitride quantum dot (Ag@CP-BNQD) nanocomposites were synthesized using a co-precipitation method followed by a hydrothermal approach. The nanocomposites of Ag@CP-BNQDs were characterized by scanning electron microscopy, energydispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, of Ag@CP-BNQDs were characterized by scanning electron microscopy, energydispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and ultraviolet−visible spectrophotometry. The as-prepared Ag@CP-BNQDs were used for photocatalytic degradation of 10 common organic pollutants, including dyes, pharmaceuticals, and pesticides in aqueous solution under visible light irradiation. The high-performance photocatalysis of Ag@CP-BNQDs proved that Ag@CP-BNQDs is plasmonic and the n−p junction photocatalyst. Theoretical calculations were done to measure the crystals and electronic structures of Ag@CPBNQDs. Theoretical results showed that loading of Ag behaves as plasmonic sensitizers and co-catalysts and provides extra bands, which make electron movement easier between valance and conduction bands. The mechanism of the charge separation enhancement was postulated. Our findings might deepen our understanding of how sensitizer surface modification works in photodegradation applications.

The goal of this research is to create nanostructured metal free phosphorous doped Boron nitride (P-BN) and phosphorous-carbon co-doped Boron nitride (CP-BN) that serve as photocatalysts when exposed to UV light. P-NPs were well diffused in aqueous solution. The nanostructured materials were characterized using XRD, SEM-EDX, and UV-Vis spectrophotometry. Based on the characterization results, phosphorous atoms were doped in the crystal structure of BN. The experimental data and theoretical calculations were used to measure the band gap energy, which was determined to be around 4.2 eV in the experimental case; for this purpose, both Tauc and Kubelka-Munk equations were utilized. Thus, photocatalysis degradation is limited to UV region. To examine the degradation effectiveness of photo-catalysts, toluidine blue (TB) was utilized; it was found that the basic medium was the best for degradation; 16% and 8% of TB were eliminated with CP-BN and P-BN, respectively after one hour degradation. Scavengers such as IPA, Na2C2O4, KBrO3, and ascorbic acid were added to trapping experiments to demonstrate the correct potential energy gap in valance and conduction bands and possible photocatalytic mechanism. Data from trapping experiments show that both the hydroxyl radical and super oxide are responsible for degradation, but electron and hole at valance and conduction bands were of low efficiency because of quick recombination. As regards computational study, the crystal and electronic structures of the P-BN and CP-BN have been studied. The lattice parameters were calculated with the Perdew-Burke-Ernzerhof (PBE), and the bandgaps (Eg) were calculated with the (PBE) as (non-local) instead of local (non-local functional generalized gradient approximations) (GAA). In addition, hybrid functional was also applied including (Becke-3 Parameter-Lee-Yang-Parr) B3LYP and (Heyd–Scuseria–Ernzerhof) exchange–correlation functional HSE06. Hybrid functional B3LYP provided better results and closer to the experimental data of the P-BN and CP-BN compound.

The current research aims to improve the cetane number of diesel extracted from the crude oil of Tawke region-Iraq Kurdistan. A specific mixture of chemical compounds was prepared which included m-nitrophenol, 4-nitro toluene, and nitrobenzene. The components' effects were investigated with regard to the cetane number, flash point, viscosity, and refractive index of diesel. The quantity of each compound mixed with diesel was prepared based on the statistical analysis of the experiment device (Box–Behnken Designs-BBDs). The tested mixture showed a good agreement and improvement of cetane and flash point and a very low effect on viscosity and refractive index. According to the statistical analysis, the main influence on cetane number and the flashpoint was from m-nitrophenol. The investigation showed that the best results were acquired from the samples of 25PPM 4-nitro toluene and 50PPM m-nitrophenol with a cetane number of 65.3. The correlation and the interaction of the regression equation were linear with all cases. It is worth mentioning that all additives positively influenced the cetane number in the regression equation. The sulfur content was measured as well, and the obtained weight percentage of sulfur was 0.8404%.

The kinetic of photo catalytic degradation of Congo red dye using semiconductor in aqueous solution of ZnO has been studied. All photochemical experiments have been carried out in quartz photo cell 25ml capacity and the solvent used for all experiment was distilled water (D. W). The influence of temperature has been investigated as well. Spectrophotometric method was utilized for this work. Degradation kinetic has been done for absorption peak of Congo red at 497 nm and 344 nm. Different method was applied for this purpose, and the results show that the degradation of Congo red was first order at 497nm and zero order at 344 nm. The degradation of CR dye were increased by increasing temperature from 20 oC to 40 oC and then degreased at 50 oC and this is due to desorption that occur at the semiconductor surface while; in case of 10 oC the rate constant was higher than 20 oC. However, when changing the concentration the rate constant dose not changed regularly, this perhaps due to the fact that it does not follow the same order throughout the degradation process, and it does not obey Arrhenius law of activation energy.

Experimental design DoE (box behnken design BBD) and statistical analysis approaches were employed to determine the effect of Congo red dye (CR) concentration, photo catalyst dose (Fe+ 2) and follow of oxygen gas as an oxidant on the degradation of CR The results show that the concentration oppositely affects the degradation yield whereas the remaining two factors show positive effect, throughout all experiments oxygen molecule shows crucial role in their positive effect with p-value about 0.01 which is very significant value. The accepted regression model was linear with significance p-value 0.032 that mean all factors show good agreement in linear relationship and the interactions was not important. Degradation kinetics was also applied to investigate the effect of increasing dye concentration on degradation rate constant with and without photo catalyst dose and oxidant (O 2). It appears that the degradation of peak at 498nm is second order The result was in good agreement with that of statistical analysis that are 0.0435, 0.0545 and 5.4 M-min-with photo catalysis 12, 8 and 4 PPM dye, 4O 2 mL/min, 20PPM Fe+ 2 respectively, in case without photocatalyst the results were 0.0025 and 0.0207 M-min-with 12 and 4 PPM in turn.

The dispersibility of carbon dots in organic and/or aqueous solvents plays a critical role in various application fields. Amphiphilic carbon dots could find broader applications due to their hydrophilic and lipophilic properties. Here, a method is described for the preparation of amphiphilic carbon dots (CDs) from white berries as a carbon source. The CDs can be well dispersed both in organic and aqueous solvents. Fluorescence is strongly red-shifted upon going from an organic solvent (in CCl4 the emission is blue with a maximum at 450 nm) to an aqueous solvent (orange fluorescence with a maximum near 600 nm). Fluorescence is independent of the excitation wavelength which is uncommon in the carbon quantum dot family. Nitrite is found to quench fluorescence in water solution, but not other common metal cations and anions. In chloroform, the fluorescence is quenched by tetracycline. The linear part of the calibration plot for nitrite covers the 5 to 90 nM concentration range, with a 1.5 nM detection limit. The linear range for tetracycline extends from 10 to 150 mM.

The photo catalytic degradation of Congo red by oxidant's and semiconductors in suspension aqueous solution of ZnO, H 2 O 2 has been studied. This work has been done by assist of RSM (surface response methodology) for design of experiments and statistical calculations. All photochemical experiments have been carried out in quartz photo cell and the solvent used for all experiment was distilled water (D. W). The influence of hydrogen peroxide H 2 O 2 , zinc oxide and dye concentration has been studied by statistical analysis. The instrument used for experiments in this work is spectrophotometer in order to find the calculated and then predicted percentage of degradation, ANOVA analysis and other statistical parameters also has been measured. The result shows that the P-values are higher than 0.05 confidence level in all experiments this means that the parameter of this work does not make a sense on percentage of degradation. This is may be due to that the hydrogen peroxide (H 2 O 2 ) may work as oxygen provider to accelerate the photo degradation process. Meanwhile, Excess amount of H 2 O 2 , Could act as hydroxyl radical capture in the mineralization system. On the other hand; the best result was 19% degradation in case of 10ppm Congo red concentration, 5% H 2 O 2 and 0.1g/L ZnO.

his work investigates the electro-catalytic degradation of alizarinblack dye in an electrochemical cell using Fe as anode and Al as cathode. The influence of initial dye concentration, effect of salt, pH, change of temperature and effect ofchange of applied voltage have been studied in addition, the influence of semiconductor dose has studied as well. In the current work roughly total removal of 70 mg/L of dye occurred in 16 minonly. The results showedthat effect of both electrolyte concentration and applied voltage was positive if combined together and the rate of degradation in neutralmedium was the best for degradation of Alizarin black dye.

the effect of polarity of solvent on the viscosity and viscosity index of lubricating engine oil has been studied using ethanol as an example of polar solvent and toluene as an example of non-polar solvent at different solvent ratios and ambient temperature and additionally other experiments have been done at five different temperatures including 100 oC. So that, the activation energy of viscous flow (Ea) was calculated, and for this purpose Arrhenius viscosity-temperature dependence has been applied and the results were 42.128, 29.256 and 35.417 KJ/mole for lubricating engine oil mixed with ethanol, toluene and no additives in turn. It additionally shows that adding polar solvent to lubrication engine oil viscosity increases this may be due to the fact of strong inter molecular forces that found in polar molecules such as hydrogen bonding in ethanol makes the solution forces stronger as a result higher viscosity. However, adding non-polar solvent decreases viscosity because of small size of toluene and both paraffinic lubricating oil and toluene have same London dispersion inter molecular forces. Last not least, the result shows that engine oil mixed with non-polar molecule gives more temperature stability than that of polar molecule giving viscosity index (VI) 366 and 580 respectively.

The photo degradation of Trifluralin by ultra violet light region has been studied in liquid phase. In this research, different concentration with different temperature has been investigated. The results have shown that increasing temperature lead to increases rate constant, but when we change concentration the rate constant dose not changed regularly. That may be due to the fact that it is not pure secondary order photo-degradation reaction. All thermodynamic parameters have been measured using second order kinetic plot and Arrhenius plot.

The photo-catalytic degradation of Toluidine Blue dye (TB) in aqueous suspension solution has been studied utilizing fluorescence light and using Zinc oxide (ZnO) as a semiconductor at variety working factors. The studied parameters were concentration of dye, semiconductor dose and the influence of pH. The result shows that expanding of ZnO dose from 20 to 60 mg/L increases the removal rate of TB dye. On the other hand, the adding of concentration from 5 to 15 mg/L show negative effect on the rate of photo-degradation. It has been denoted that the percentage of dye degradation come to the peak value at high acidic medium. 11 % of TB dye was adsorbed, in dark condition, by ZnO. In addition, the kinetics of degradation has been examined and the degradation was found to take after pseudo-first order kinetic model.