UV Vis Diffuse Reflectance Research Articles

Unveiling the green synthesis of WO3 nanoparticles by using beetroot (Beta vulgaris) extract for photocatalytic oxidation of rhodamine B.

Tungsten oxide (WO3) nanoparticles (WO3NPs) were prepared using beetroot (Beta vulgaris) extract. The synthesis was optimized by evaluating the effect of pH during the reduction of the WO3 precursor and sintering temperature. Physicochemical characterization of the formed nanoparticles was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-visible diffuse reflectance UV-visible spectroscopy. Furthermore, the prepared WO3NPs were employed as photocatalyst for rhodamine B removal over the photocatalytic oxidation mechanism. Synthesis optimization revealed that a single phase of WO3NPs obtained by reduction at pH 4 and a sintering temperature of 550°C. XRD and XPS measurements revealed that the single-phase WO3NPs was obtained with a crystallite size of 26.4 nm. SEM and transmission electron microscopy (TEM) indicated polymorphic forms, predominantly as nanorods, with a mean particle size of 24 nm. The WO3NPs have a band gap energy of 2.9 eV, supporting their performance as a photocatalyst. Evaluation of the photocatalytic activities of WO3NPs represents high activity and reusability of the material. A removal efficiency of 99.67% was achieved during 30 min of treatment under UV light illumination. A study on the effect of scavengers revealed the important role of hydroxy radicals in the photocatalysis mechanism. WO3NPs can be recycled and reused for photocatalysis, maintaining photoactivity for five cycles.

Synthesis, Optical, and Magnetic Properties of the Mixed Chalcogenide Semiconductor Series Eu(II)2SiSexS4-x, Prepared via the Flux-Assisted Boron Chalcogen Mixture Method.

We report a detailed structural study of a series of five new quaternary Eu(II)-containing mixed chalcogenide phases, Eu2SiSe0.85S3.15, Eu2SiSe2.4S1.6, Eu2SiSe2.6S1.4, Eu2SiSe3.1S0.9, and Eu2SiSe4, synthesized using the flux-assisted boron chalcogen mixture (BCM) method. High-quality crystals were grown, and their crystal structures were determined by single-crystal X-ray diffraction. All members of the Eu2SiSexS4-x series crystallize in the monoclinic crystal system with space group P21/m, except Eu2SiSe4, which crystallizes in the P21 space group. The crystal structure of Eu2SiSexS4-x exhibits a complex three-dimensional network and is primarily composed of distorted trigonal prismatic EuQ6 polyhedra that are interconnected by SiQ4 tetrahedra. Polycrystalline powders were used for physical property measurements, including the magnetic susceptibility and UV-vis diffuse reflectance. Magnetic measurements indicated paramagnetic behavior with a slightly negative Weiss constant (θ = -13.54). The band gaps of the materials were determined from diffuse reflectance data, with optical band gaps estimated to be 2.04(2) eV, 1.98(2) eV, and 1.90(2) eV for Eu2SiSe0.85S3.15, Eu2SiSe2.6S1.4, and Eu2SiSe4, respectively. Band gap tuning was achieved by partially or fully replacing the S sites with Se.

Fabrication of C and N co-doped CdS semiconductor photocatalysts derived from a novel Cd-MOF for enhancing photocatalytic performance

The narrow bandgap value and long lifetime of photo generated charges make CdS exhibit higher photocatalytic activity compared to other semiconductor catalysts. Given the excellent optoelectronic properties of CdS, a novel 2D cadmium-organic framework (Cd-MOF) was obtained by solvothermal method, which was served as a precursor template in this paper. C and N co-doped CdS-T (T = 600/800/1000) semiconductor materials were successfully prepared by chemical deposition method under different high temperatures. The as-prepared materials had been characterized in detail. Furthermore, the Cd-MOF and CdS-T were used to conduct the photocatalytic activity of organic dyes. Among them, CdS-800 showed excellent photocatalytic degradation effects on five organic dyes, especially on RB with the photocatalytic degradation efficiency of 98.87 %, which was significantly improved 6.5 times compared to Cd-MOF (58.23 %). Free radical capture experiments have shown that •O2− play a dominant role in the photocatalytic process. In addition, UV–vis diffuse reflection, photoluminescence (PL), photoelectrochemical (PEC) testing and density functional theory (DFT) calculations had shown that CdS-800 could effectively delay the recombination of photo generated charges, improve the rapid migration and separation of photo generated carriers, and enhance photocatalytic activity. This work provides new ideas for the preparation of efficient and recyclable CdS semiconductor photocatalytic materials.

Innovative synthesis and practical application of graphitic carbon nitride/α-zirconium phosphate in visible light-activated Knoevenagel condensation

To advance the development of efficient photocatalysts activated by visible light for environmental applications. We employed a simple approach to synthesize g-C3N4/α-ZrP composite in different mass ratios, followed by comprehensive characterization through several techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM/EDS), and UV–Visible diffuse reflectance spectra (DRS). Furthermore, the g-C3N4/α-ZrP with mass ratio 6:1 was demonstrated high performance catalytic activity in Knoevenagel condensation (Yield 88 %–96 %) in a short reaction time (5–20 min) under visible light irradiation. The use of g-C3N4/α-ZrP has transformed the traditional synthesis of carbon–carbon double bonds, offering improved reaction rates and reduced by-products. These next-generation photocatalysts also exhibit remarkable properties that facilitate the activation of substrates under milder conditions, opening up new possibilities for green and sustainable synthesis. This advancement contributes to the development of environmentally friendly and efficient synthetic methodologies.

Characterization of Ti-MOF derived TiOx assembled with different carboxylic acid organic ligands and differences in their CO2 photothermal catalytic reduction performance

The photothermal catalytic conversion of carbon dioxide into fuel gas is a promising technology for simultaneously addressing environmental and energy challenges. Currently, widely used metal oxide-based catalysts, such as TiO2, often show significant performance variations depending on the preparation methods. Therefore, developing metal oxides with superior photothermal catalytic properties is a key approach to producing high-performance composite catalysts. This article discusses the preparation of high-performance metal oxide catalysts derived from MOFs. By regulating four different carboxylic acid organic ligands to assemble with Ti-O clusters into various precursors, TiOx was derived and prepared. Techniques such as XRD, infrared spectroscopy, XPS,TEM, SEM, N2 adsorption–desorption analysis, CO2-TPD, H2-TPR, PL spectrum, Raman spectra, UV–visible diffuse reflectance spectroscopy, photoelectrochemical characterization, and others were used to comprehensively explore the structure, surface properties, and photoelectric properties of the derivatives influenced by the organic ligands. Derivatives were subjected to photothermal catalytic reduction of carbon dioxide in hydrogen rich gas without metal loading, and the intermediate pathway of the reaction was investigated through in situ DRIFTS spectra. Research has shown that organic ligands have a significant impact on the morphology, surface properties, and optoelectronic properties of derivatives. The TiOx derived from the precursor assembled with 2-aminoterephthalic acid as an organic ligand has a larger specific surface area, abundant oxygen vacancies, excellent photoelectric conversion ability, and surface electron migration performance. Under the condition of coupled light irradiation at 400 ℃, a CO yield of 4944.81 μmol/g was achieved, with a selectivity of 99.89 %. The reaction follows the formate pathway. This study provides valuable reference for the development and modification of high-performance TiO2 based catalysts.

Advancing photocatalytic performance for enhanced visible-light-driven H2 evolution and Cr (VI) reduction of g-C3N4 through defect engineering via electron beam irradiation

Defect engineering has emerged as a strategic approach for optimizing photocatalyst band structures to improve performance. High-energy electron-beam irradiation is a promising method for inducing vacancies and defects in semiconductor materials, providing a rapid and efficient solution. In this study, we used simple electron-beam irradiation to modify g-C3N4 photocatalysts, resulting in the rapid formation of nitrogen vacancies within the material. Characterization techniques such as 13C-nuclear magnetic resonance, X-ray photoelectron spectroscopy, and electron paramagnetic resonance confirmed the formation of nitrogen vacancies, resulting in an asymmetric charge distribution within the g-C3N4 crystal structure. The optimized photocatalyst, gCN-300, exhibited remarkable performance, producing hydrogen at a rate of 750.57 ± 9.9 μmol g-1h−1 and reducing Cr (VI) by 83.5 % within 2 h with long-term photostability. The improved performance was attributed to increased visible-light absorption, a greater number of surface-active sites, improved electronic conductivity, and efficient charge transfer. These factors were supported by UV–visible diffuse reflectance spectroscopy, photoluminescence, and photoelectrochemical analysis. Thus, this study demonstrates the effectiveness of electron-beam irradiation in the large-scale production of defect-engineered photocatalysts with high performance.

Effects of adding copper to bismuth titanate for photocatalytic hydrogen production

In this work, pure and copper-doped bismuth titanate perovskites were synthesized using the modified amorphous citrate method to evaluate the influence of the dopant on the material's structure and its efficiency as a catalyst. X-ray diffraction method has been employed for the analysis of the crystal structure while scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques were used to examine the material's morphology. Electron dispersion spectroscopy (EDS) was also employed to confirm the doping of the material. The doped material exhibited a bandgap within the visible region calculated using the Tauc plot from UV-Vis diffuse reflectance spectroscopy. The dopant influenced the emergence of secondary bandgaps with considerably lower values than the pure materials, directly impacting the photocatalytic performance of hydrogen gas (H2) production. The highest H2 gas production occurred in the doped and more crystalline sample. Comparing these results with other studies, it can be concluded that copper is a metal with great potential as a dopant for the development of bismuth titanate-based catalysts.

In situ construction of CuBi2O4/Bi4O5Br2 Z-scheme heterojunction with enhanced photocatalytic degradation performance for polyphenolic contaminant in wastewater

Photocatalytic technique is one of the clean and promising routes for wastewater purification. In this work, a different CuBi2O4/Bi4O5Br2 Z-scheme heterojunction were successfully prepared via an in-situ mechanical agitation method. The 10% CuBi2O4/Bi4O5Br2 (10% CBO/BOB) heterojunction showed the highest photocatalytic degradation activity for catechin, and ∼99.8% catechin was degrade within 40 min visible light stimulation, which is (0.0757/min) about 6.2-folds and 8.8-folds to that of Bi4O5Br2 (0.0122/min) and CuBi2O4 (0.0086/min), The pH=7 is the optimal reaction condition for catechin degradation. Besides, The photocatalytic degradation capacity of the 10% CBO/BOB heterojunction displayed the positive and negative relationship to the dosage of catalyst and initial concentration of catechin, respectively. The enhanced photocatalytic activity of CuBi2O4/Bi4O5Br2 Z-scheme heterojunction can be ascribed to the improvement of the charge separation and light utilization rate. The results of ESR and trapping experiments revealed that the ·O2-, h+ and ·OH are the primariy reactive substances for catechin degradation. Additionally, the transfer pathway of the photogenerated charges in the CuBi2O4/Bi4O5Br2 Z-scheme heterojunction as revealed by the ESR, Mott-Schottky curve and UV-Vis diffuse reflectance absorption spectroscopy. This work provide a new idea for designing and preparing the novel Bi4O5Br2-based photocatalyst for TCM wastewater purification.

Preparation of Biochar-Loaded Er3+-Doped BiOCl Ultrathin Nanosheets Composite Photocatalysts and Their Photodegradation Performance of TC-HCl

In this study, biochar-loaded E3+:BiOCl (C/3E3+:BiOCl) was synthesized with varying levels of E3+ doping using a one-step solvothermal method and used for tetracycline hydrochloride (TC-HCl) degradation. Their structure, shape and morphology were not only characterized by power X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) but also by UV-vis diffuse reflectance spectra and upconversion (UC). The results indicated a significant enhancement in the photocatalytic activity of the catalyst following the introduction of Er3+. The composite material C/3E3+:BiOCl, with a doping concentration of 3 mol%, demonstrated the highest photocatalytic activity, achieving an impressive visible light degradation efficiency of 89.2% for TC HCl within 90 min. This marks an increase of 33.5% compared to the BiOCl monomer and 17.4% compared to C/BiOCl. Additionally, when exposed to light with wavelengths exceeding 600 nm, C/3E3+:BiOCl maintained a photodegradation efficiency of 44.3%, while BiOCl and C/BiOCl showed no photocatalytic activity under the same conditions. This finding highlights the effectiveness of BiOCl as a doping matrix, which enhances the photocatalytic performance of BiOCl through the upconversion effect of E3+ and the electron transfer mechanisms associated with biochar.

Modulating Electronic Structure of MoS2 Nanosheets by Sulfide Enrichment‐Induced Vacancies for Enhanced Photocatalytic Hydrogen Production

AbstractEnhancing photocatalytic activity by changing the electronic structure of the catalyst is an effective strategy. 2H‐MoS2 has semiconductor properties, and its unsaturated side S atom is the main active site for its photocatalytic activity. However, due to the weak S─H bond energy, its hydrogen adsorption capacity is weak. In this work, the electronic structure of MoS2 is adjusted by S‐rich treatment, resulting in the formation of Mo vacancy (MoS2‐VMo). The level of Mo vacancies was assessed using UV–vis diffuse reflectance spectroscopy (UV–vis DRS). As these vacancies can capture certain photogenerated electrons, thereby reducing the recombination of electron‐hole pairs. Through DFT calculation, it is found that the antibonding orbital electron filling of MoS2‐VMo is weakened, the bond energy of S─Mo bond is weakened, and the bond energy between S─H bond is enhanced, which is more conducive to proton adsorption. The photocatalytic activity for hydrogen evolution of MoS2‐3, which underwent the optimal S‐rich treatment, achieved a remarkable rate of 2404.6 µmol g−1 h−1 in dye eosin Y (EY) sensitization system, significantly surpassing that of MoS2 lacking the S‐enriched treatment. This study introduces a novel concept for enhancing the photocatalytic hydrogen evolution performance of metal sulfides via defect engineering.

TiO2/NiFe2-xCexO4/rGO ternary magnetic nanocomposite as separable and recyclable photocatalyst

This study investigates the synthesis and application of a TiO2/NiFe2-xCexO4/rGO ternary magnetic nanocomposite as an efficient and recyclable photocatalyst. The nanocomposite was characterized using Fourier-transform infrared(FTIR), X-ray diffraction(XRD), Field emission scanning electron microscopy(FE-SEM), magnetic measurements, UV–Vis diffuse reflectance spectroscopy(DRS), and X-ray photoelectron spectroscopy (XPS). FTIR analysis confirmed the formation of the inverse spinel cubic structure, with significant vibrational bands related to metal–oxygen complexes. XRD patterns showed successful incorporation of Ce3+ ions into the NiFe2O4 lattice, with shifts in diffraction peaks indicating changes in crystallite size and lattice parameters. FE-SEM images revealed a well-dispersed distribution of TiO2 and NiFe2O4 nanoparticles on the reduced graphene oxide (rGO) surface, enhancing the nanocomposite’s structural integrity. Energy dispersive X-ray(EDX) analysis demonstrated the presence of Ti, Ni, Fe, Ce, O, and C elements in the ternary nanocomposite without impurities, confirming the high purity of the material. Magnetic measurements indicated increased magnetization due to Ce3+ doping. DRS revealed optical band gaps (Bg), and XPS provided detailed insights into the surface chemical composition and valence states. XPS analysis confirmed the presence of Ni2+, Fe3+, Ti4+, and Ce3+ ions, and verified the reduction of graphene oxide to rGO. Importantly, the XPS data also indicated a reduction in the binding energy of oxygen species, which suggests effective electron trapping. The photocatalytic performance was assessed by the degradation of methylene blue (MB) under UV and Vis light. The TiO2/NiFe2-xCexO4/rGO nanocomposite demonstrated superior photocatalytic activity with high degradation rates. The enhanced photocatalytic efficiency is attributed to efficient electron trapping, which reduces electron-hole recombination. Furthermore, the nanocomposite showed excellent reusability, maintaining high photocatalytic efficiency over multiple cycles of use, which underscores its potential for practical applications in environmental remediation.

Efficient Catalytic Reduction of Organic Pollutants Using Nanostructured CuO/TiO2 Catalysts: Synthesis, Characterization, and Reusability

The catalytic reduction of organic pollutants in water is a critical environmental challenge due to the persistent and hazardous nature of compounds like azo dyes and nitrophenols. In this study, we synthesized nanostructured CuO/TiO2 catalysts via a combustion technique, followed by calcination at 700 °C to achieve a rutile-phase TiO2 structure with varying copper loadings (5–40 wt.%). The catalysts were characterized using X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR–FTIR) spectroscopy, thermogravimetric analysis-differential thermal analysis (TGA–DTA), UV-visible diffuse reflectance spectroscopy (DRS), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDS). The XRD results confirmed the presence of the crystalline rutile phase in the CuO/TiO2 catalysts, with additional peaks indicating successful copper oxide loading onto TiO2. The FTIR spectra confirmed the presence of all the functional groups in the prepared samples. SEM images revealed irregularly shaped copper oxide and agglomerated TiO2 particles. The DRS results revealed improved optical properties and a decreased bandgap with increased Cu content, and 4-Nitrophenol (4-NP) and methyl orange (MO), which were chosen for their carcinogenic, mutagenic, and nonbiodegradable properties, were used as model organic pollutants. Catalytic activities were tested by reducing 4-NP and MO with sodium borohydride (NaBH4) in the presence of a CuO/TiO2 catalyst. Following the in situ reduction of CuO/TiO2, Cu (NPs)/TiO2 was formed, achieving 98% reduction of 4-NP in 480 s and 98% reduction of MO in 420 s. The effects of the NaBH4 concentration and catalyst mass were investigated. The catalysts exhibited high stability over 10 reuse cycles, maintaining over 96% efficiency for MO and 94% efficiency for 4-NP. These findings demonstrate the potential of nanostructured CuO/TiO2 catalysts for environmental remediation through efficient catalytic reduction of organic pollutants.

Facile synthesis and characterization of zinc molybdate (ZnMoO4) nanosheets for electrochemical supercapacitor application

Abstract This study explores the synthesis and characterization of zinc molybdate (ZnMoO4) nanosheets with emphasis on their potential application for energy storage devices particularly supercapacitors. The synthesis of ZnMoO4 nanosheets was done through co-precipitation followed by examination of their structure, morphology, optical, thermal behaviour and electrochemical performance by various characterization techniques. X-ray diffraction (XRD) analysis confirmed that the formation of monoclinic ZnMoO4 phase with the average crystallite size 17.93 nm. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) revealed that this material had nanosheets-like structure which helps to increase ion transport and surface area; these two factors are essential for enhancing the material’s supercapacitor efficacy. The semiconductor characteristics were determined using UV–Visible diffuse reflectance spectroscopy (UV-DRS) which indicated a band gap energy of 4.2 eV. Fourier transform infrared (FTIR) analysis confirmed that the presence of Zn–O and Mo–O bonds in their crystal lattice. Thermogravimetric analysis (TGA) showed that the ZnMoO4 nanosheets had thermal stability since they experienced only a slight mass loss of 2.57 % up to 800 °C. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) tests were undertaken to find out the specific capacitance and the value is 618 F g⁻1 at a current density of 1 A g⁻1.

Synthesis and application of aluminum substituted ZnO nanowires on carbon fibers photocatalyst for the removal of methylene blue dye from aquatic mediums

In this research, pristine and aluminum substituted ZnO nanowires grown on carbon fibers synthesised by hydrothermal method. The effect of Al concentration on morphology, structure, optical properties and photocatalytic activity on methylene blue was investigated. The aluminum concentration values of 0.5 %, 1 %, 5 % and 10 % of Zn(NO3)2·6 H2O concentration were tested. Resulting structures were characterized by scanning electron microscopy, X-ray Diffraction, diffuse reflectance spectroscopy and UV-Vis diffuse reflectance spectroscopy. XRD results indicates that pristine and aluminum substituted ZnO nanowires has hexagonal zincite crystal structure. The changes of crystal size, crystal parameters, strain and stress with aluminum substitution were investigated. Increasing concentration of aluminum reduced the crystallinity of ZnO. A dramatic change was seen in crystallite size from 40.78 nm to 22.73 nm. Distortion is seen on crystal structure of substituted ZnO causing stress due to different ionic radii between Zn2+ and substituent ions. Tensile stress of 1.38 Pa is calculated for aluminum substituted ZnO nanowires. Smaller ionic radii of aluminum causes positive tensile stress. Optical band gap of structures was analysed. Al substitution reduces the band gap of ZnO NWs/CFs. DRS results shows that Al incorporation led to a 0.05 eV decrease in the bandgap of ZnO NWs/CFs structure. Photocatalytic activity of pristine and aluminum substituted ZnO nanowires on carbon fibers structures were tested on degradation of methylene blue (MB). Al substitution enhances the photocatalytic activity of ZnO nanowires coated on carbon fibers. 1 % Al substituted ZnO NWs on CFs demonstrated highest degradation efficiency with 0.9879 h−1 kinetic rate.

Synthesis, crystal structure, Hirshfeld surface analyses and antibacterial activity of 2-fluorobenzylpyridinium tetrabromidocuprate(II)

In this article, novel organic-inorganic hybrid material, 2-fluorobenzylpyridinium tetrabromidocuprate(II) [2FBzPy]2[CuBr4], has been obtained by using a slow evaporation solution-growth method and was characterized by powder X-ray diffraction, infrared spectroscopy, scanning electron microscopy, UV–visible diffuse reflectance spectrum. The compound crystallizes in the monoclinic space group P21 /c, and the packing is governed by C − H···Br hydrogen bonding interactions, which was confirmed by the Hirshfeld surface analysis. The results of antimicrobial experiments showed that the compound possessed excellent antimicrobial activity against Staphylococcus aureus and Escherichia coli. RESEARCH HIGHLIGHTS An inorganic-organic hybrid salt [2FBzPy]2[CuBr4] was synthesized and characterized. The main intermolecular interaction in [2FBzPy]2[CuBr4] crystals have been studied and analyzed. The interactions between different molecules in[2FBzPy]2 [CuBr4] were examined by Hirshfeld surface analyses. [2FBzPy]2[CuBr4] had an optical band gap of 1.69 eV, was a typical semiconductor material with good optical property. The as-synthesized salts exhibits good antibacterial activities against S. aureus and E. coli.

Design of novel Z-scheme Ce2(WO4)3 heterostructure using tubular g-C3N4 for boosted photocatalytic performance via effective electron transfer pathway

Herein, we report a novel Z-scheme heterostructure catalyst based on tubular shaped graphitic carbon nitride with cerium tungstate catalysts synthesized by ultrasonic-assisted thermal impregnation route. The physicochemical, morphological and optical features of the materials were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance (UV–vis DRS), photoluminescence (PL) spectroscopy and N2-adsorption-desorption measurements. The results demonstrated that the Ce2(WO4)3/g-C3N4 hybrid catalyst achieved superior photocatalytic activity although they had poor performance individually. The kinetic rate constant of the hybrid sample was calculated as 0.0134 min-1 which was 3.4 times higher than the pristine Ce2(WO4)3 for the degradation of tetracycline antibiotic under visible light irradiation. The improved catalytic activity was assigned to higher surface area, narrower band gap energy and formation of Z-scheme heterojunction mechanism between Ce2(WO4)3 and g-C3N4 according to band structure analysis. This research demonstrated the potential utilization and modification of Ce2(WO4)3 as a new metal tungstate in the photocatalytic remediation of different types of pollutants.

Visible light sensitive BiVO4–TiO2 nanocomposites for photocatalytic dye degradation

Abstract The hydrothermal approach was used to prepare visible light active BiVO4–TiO2 nanosheet composites in varying molar ratios. The photoluminescence (PL) spectrum, X-ray photoelectron spectroscopy (XPS), UV-Visible Diffuse Reflectance Spectroscopy (DRS), Transmission electroscopy (TEM), Brunauer-Emmett-Teller (BET) and field emission scanning electron microscopy (FESEM), were used to analyze the photocatalysts and composites. Photocatalytic activity of BiVO4–TiO2 composites was investigated by decolorizing methylene blue. Out of four different molar ratio BiVO4–TiO2 composites with a molar ratio of 3:1 BiVO4 TiO2 composite showed enhanced photocatalytic activity which is further proved by photoluminescence investigation of coumarin and Scavenger test. The DRS of BiVO4 TiO2 composite showed red shift in optical absorption. The enhanced photocatalytic activity is due to minimizing electron hole recombination by making composite with TiO2.

Different metal-doped NiO nanoparticles for sunlight-mediated degradation of low-density polyethylene microplastic films.

Due to the widespread use and incorrect handling of plastics, we need to find a practical and effective way to eliminate plastic waste from the environment. Different metal-doped nickel oxide (DMD-NiO) nanoparticles (NPs) were synthesized using a sol-gel technique and were used to degrade low-density polyethylene (LDPE) microplastic (MP) films when exposed to sunlight. The optical and structural properties of sol-gel method synthesized materials were investigated using a variety of characterization methods (Fourier transform infrared (FT-IR), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), X-ray diffractometer (XRD) analysis, X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, and thermogravimetric analysis (TGA). Degradation study results suggest that the photocatalytic activity of DMD-NiO-LDPE nanocomposites (NCs) films was greater than that of pure LDPE and undoped NiO-LDPE films. Because of their increased optical absorption and efficient suppression of photo-produced charge carriers' recombination, the DMD-NiO NPs showed higher photocatalytic degradation of LDPE films. Thus, LDPE films with 2% wt Fe-NiO (iron-doped nickel oxide) nanomaterials showed a degradation of around 38.16% among DMD-NiO-LDPE NCs films under visible light over a short period of 30 days (240 h). The formation of carbonyl groups in the degradation product of LDPE was confirmed by Fourier transform infrared (FT-IR) analysis. When compared to the original LDPE film, the Fe-NiO-LDPE NCs films showed a significant decrease in crystallinity and carbonyl indexes, as much as 8.4% lower. The current project proposes the development of eco-friendly photocatalysts using a sol-gel technique for combating MP pollution in the environment.

La-supported SnO2–CaO composite catalysts for efficient malachite green degradation under UV–vis light

This study presents the development and optimization of La@SnO2–CaO composite catalysts for efficient photocatalytic degradation of malachite green dye in aqueous solutions under UV–vis light irradiation. The catalysts were prepared via conventional incipient-wetness impregnation and thoroughly characterized using advanced analytical techniques, including X-ray diffraction, Fourier transform infrared spectroscopy, UV–vis diffuse reflectance spectroscopy, N2 adsorption–desorption analysis, and scanning electron microscopy. To optimize photodegradation efficiency, the effects of three independent factors were systematically investigated using response surface methodology: Temperature, pH, and Sn/Ca molar ratio. Our results reveal optimal conditions for maximum dye degradation: pH 7, Sn/Ca molar ratio of 0.33, and a process time of 35 min, resulting in a maximum photodegradation efficiency of 98.80% for malachite green dye. Notably, visible light exhibited a more pronounced effect on dye degradation compared to UV light over time, with visible light achieving 25% greater dye removal after 60 min of illumination. Furthermore, the catalyst showed excellent recyclability, retaining 85% of its initial activity after five consecutive cycles. These findings contribute significantly to the development of sustainable methods for dye removal from wastewater and highlight the potential of La@SnO2–CaO composite catalysts in environmental remediation processes, particularly in treating textile industry effluents.

Phytomediated synthesis of WO3 nanoparticles using Solanum lycopersicum fruit extract for enhanced photocatalytic activity of 2,4-dichlorophenol.

In the present study, bio-citric acid/tungsten oxide (WO3) (BCAWO) nanoparticles (NPs) were prepared by using Solanum lycopersicum fruit extract as a reducing as well as a capping agent. The photocatalysts were characterized by UV-vis diffuse reflectance spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), high-resolution transmission electron microscopy, and photoluminescence spectroscopy techniques. Diffraction peaks in the XRD spectrum were identified as the crystal planes of crystalline tungsten oxide. The BCAWO had an average size of 23.14 nm. For W-O bonds, the Fourier transform infrared spectrum displays the vibrational peak at 671.23 cm-1. A prominent absorption band was observed at 268 nm, indicating the 1.2 eV bandgap. Under xenon (Xe) lamp irradiation, the synthesized BCAWO nanoparticles showed notable photocatalytic degradation of 2,4-dichlorophenol (2,4-DCP), with a degradation rate of 96%. With BCAWO concentrations of 2.5 g/L, pH of 4, reaction period of 180 min, and 2,4 DCP concentration of 10 mg/L, the degradation of 2,4-DCP had the highest efficacy, 96%. The degradation of phenols in wastewater may be facilitated by using the green WO3 nanoparticles as a photocatalyst, according to the results.