Photocatalytic Degradation Of Pollutants Research Articles

Enhanced photocatalytic degradation of organic pollutants by green-synthesized gold nanoparticles using polysaccharide for environmental remediation

The recent rise in textile dye wastewater discharge into the environment has detrimental effects on living organisms and human health. The present study reports a facile approach to green-synthesized AuNPs employing sesbania gum for catalytic and photocatalytic degradation of organic pollutants. The obtained AuNPs were characterized by various techniques such as UV–vis, FT-IR, SEM, TEM, AFM, zeta potential, LC-MS, and XPS. The XRD patterns revealed a highly crystalline and face-centered cubic structure. XPS and EDX analysis defined the chemical composition and product purity of SBG-AuNPs. Photocatalytic degradation of hazardous dyes congo red and safranin-O using SBG-AuNPs showed a rapid decomposition rate with 94.69 % under visible light irradiation. The effect of pH, dye concentration, and catalyst dose on photodegradation and recyclability was also studied. The kinetic plots were used to calculate the rate constant, showing a pseudo-first-order reaction. Scavenger trap experiments confirmed the role of h+ and superoxide(.O2−) as active species, and LCMS analysis was used to identify the degradation intermediates. The catalytic reduction of SBG–AuNPs was studied for brilliant green (BG) and methylene blue (MB) in the presence of NaBH4, resulting the degradation efficiency of 90.37 % and 84.52 %, respectively. This study presents an innovative approach for designing highly efficient photocatalysts for environmental remediation and wastewater treatment from textile dyes.

Reinforcing 2D Single-Crystal Bi2O2CO3 with Additional Interlayer Carbonates by CO2-Assisted Solid-to-Solid Phase Transition.

A facile gaseous CO2 mediated solid-to-solid transformation principle is adopted to insert additional CO3 2- anions into the thin single-crystal nanosheets of Bi2O2CO3, which is built of periodic arrays of intrinsic CO3 2- anions and (Bi2O2)2+ layers. The additional CO3 2- anions create abundant defects. The Bi2O2CO3 nanosheets with rich interlayer CO3 2- exhibit superior electronic properties and charge transfer kinetics than the pristine single-crystal 2D Bi2O2CO3 and display enhanced catalytic activity in photocatalytic CO2 reduction reaction and the photocatalytic oxidative degradation of organic pollutants. This work thus illustrates interlayer engineering as a flexible means to build layered 2D materials with excellent properties.

Ultrathin Sulfur‐Doped g‐C3N4 Nanosheets Controlled by Steam Activation for Enhanced Visible‐Light Photocatalytic Performance

AbstractGraphite carbon nitride (g‐C3N4) has garnered considerable attention due to its excellent photocatalytic properties for the degradation of organic matter in wastewater treatment. Herein, sulfur‐doped g‐C3N4 nanosheets (CN−S‐X) were successfully synthesized via physical steam activation using thiourea and urea as precursors. Comprehensive characterizations demonstrate that the enhanced photocatalysis is attributed to the ultrathin structure, highly active site, vacancy defects, and high specific surface area due to the synergy of S doping and steam activation. The as‐prepared CN−S‐25 photocatalyst exhibits a desirable degradation efficiency of 95.4 % for methylene blue dye with a high degradation rate of 2.65×10−2 min−1 under visible‐light irradiation, which are 2.1 and 5.52 times those for bulk g‐C3N4, respectively as well as good reusability and stability. This study provides a simple and promising strategy to regulate the nanostructure of g‐C3N4 for highly efficient photocatalytic degradation of organic pollutants.

Novel existence of Mn and Cu in WO3 nanostructures for promising photocatalytic activity against MB dye and Levofloxacin antibiotic

To enhance photocatalytic degradation of MB dye and Levofloxacin antibiotic, facile coprecipitation strategy was used to synthesize pure WO3 and novel Mn-Cu codoped WO3 nanostructures. The synthesized nanostructures were probed by XRD, SEM, EDX, FTIR, XPS, BET, TEM, PL and UV–vis spectra to analyze optical and morphological properties. Pure WO3, Mn2%-Cu1%-WO3, Mn2%-Cu3%-WO3, Mn2%-Cu5%-WO3 and Mn2%-Cu7%-WO3 were optimized novel materials that were used for water treatment against model impurities. Optical properties of pure WO3 were enhanced to successfully increase the photocatalytic degradation of principal water pollutants. Over a time span of 175 minutes, 86.7% of MB dye was degraded and 75.9% Levofloxacin was degraded by an average of 49 nm and 2.16 eV bandgap Mn2%-Cu5%-WO3 optimal sample. Due to smaller particle size, surface to volume ratio gave more active sites to the photocatalysts for pollutants degradations. Interestingly, just 15% degradation loss was observed after consecutive 6 cycles against the degradation of MB dye and 9.1% loss against Levofloxacin medicine after 6 photocatalytic runs. XPS spectra offered crucial insights into the elemental composition and chemical states of the Mn-Cu-WO3 nanostructures. According to these findings, Mn-Cu-WO3 can be used as a good candidate with long time stability against pollutants degradations.

Bifunctional S-scheme Fe7S8/CuIn5S8 heterostructures with S-vacancies for boosted photocatalytic antibiotic degradation and hydrogen evolution

The reasonable designing, interfacial tuning and construction of S-scheme heterostructures offering high performance water pollutants treatment and energy production still remains challenging. Following the structure, band structure and interface function perspective, we prepared Fe7S8/CuIn5S8 heterostructures photocatalysts with sulfur vacancies for superior norfloxacin (NOR) degradation and hydrogen production under visible light. In particular, for optimal 30FS/CIS (30%Fe7S8/CuIn5S8), the H2 evolution was up to 35.6 mmol g−1 h−1 which was 11.5 times than pristine Fe7S8 with TEOA as sacrificial agent. The heterojunction could also show 98.7% degradation of NOR in 90 min under visible light. Interestingly, using NOR pollutant as sacrificial agent under synergistic conditions, 22.7 mmol g−1 h−1 H2 evolution and 98.9% degradation of NOR (in 45 min) was achieved. The significantly boosted photocatalytic pollutant degradation and hydrogen generation performance over Fe7S8/CuIn5S8 hybrids is ascribed to the efficient S-scheme charge transfer and active sites provided by sulfur vacancies (Vs). The deep electron transfer mechanism and the charge transfer efficiency were supported by in-situ XPS, UPS, electrochemical experiments and photoluminescence. Experimental results including scavenging tests and ESR findings provided the direct evidence of photogenerated holes and ●OH radicals for pollutant degradation and electrons in hydrogen generation. This work contributes to effective designing and developing high-activity visible light/solar light assisted heterojunction photocatalysts for realizing superior clean energy generation and pollutant degradation.

Persistent production of multiple active species with copper doped zinc gallate nanoparticles for light-independent photocatalytic degradation of organic pollutants

Photocatalysis is considered as an environmentally friendly and sustainable method as it can produce active species to degrade pollutants. However, its applications are hindered by the turbidity of pollutants and the requirements for continuous or repeated in situ irradiation. To avoid the need for continuous in situ irradiation in the photocatalytic process, herein we report the doping of Cu(II) ions into zinc gallate (ZnGa2O4) as traps to capture photo-generated electrons. In this way, long lifetime charge release and separation were effectively achieved for the persistent degradation of organic dyes in wastewater. The Cu(II) doped ZnGa2O4 (ZGC) nanoparticles with a small size about 7.7 nm synthesized via a hydrothermal method exhibited a persistent photocatalytic activity with continuous production of reactive oxygen species for at least 96 h without in situ irradiation due to its unique electronic structure and carrier transport path, and enabled to degrade 82.2 % of rhodamine B in 1 h. Further investigation revealed that the doped Cu(II) ions occupied the octahedral sites of ZGC and highly increased the persistent production and availability of active species for the persistent degradation of organic dyes under pre-illuminated conditions.

Enhanced photocatalytic degradation of organic pollutants in actual sewage water with a full-spectrum-responsive NaYF4:Yb,Tm@NaYF4:Yb,Nd@TiO2@g-C3N4 nanoheterojunction photocatalyst

Full spectrum-excitation photocatalysis is promising for the environmentally friendly treatment of actual sewage with sunlight. High-efficiency, stable NaYF4:Yb,Tm@NaYF4:Yb,Nd@TiO2@g-C3N4 (UPTC) nanoheterojunction photocatalysts were fabricated via facile chemical synthesis. Nanophotocatalyst characterization revealed good crystallinity, strong composite formation, and a high separation rate of photoexcited charges. The synthesized UPTC was excited by ultraviolet, visible light and infrared light, exhibiting excellent full spectrum-response. Under near-infrared irradiation at 808 nm and 980 nm, UPTC effectively degraded rhodamine B (RhB). Under simulated sunlight, UPTC decomposed 88.6% malachite green, 92.2% rose bengal, and 90.8% RhB in 90 min. In photocatalysis, ·O2- played a dominant role. Moreover, the nanoheterojunction structure greatly improved photoexcited carrier separation. UPTC nanoheterojunction had excellent recycling capability. In actual sewage treatment, UPTC degraded 36.5% ammonia-nitrogen under simulated sunlight. In addition, UPTC exhibited sufficient biosafety. This study offers a fresh potential approach for producing highly efficient, stable, and biosafe nanoheterojunction photocatalysts for sewage treatment.

Simultaneous photocatalytic removal of tetracycline and hexavalent chromium by BiVO4/0.6CdS photocatalyst: Insights into the performance, evaluation, calculation and mechanism

In this study, a novel Z-scheme heterojunction on bismuth vanadium/cadmium sulfide (BiVO4/0.6CdS) was developed and evaluated for simultaneous photocatalytic removal of combined tetracycline (TC) and hexavalent chromium Cr(Ⅵ) pollution under visible light. Based on the analysis of intermediate products and theoretical calculation, the property of the intermediate products of TC degradation and the effect of built-in electric field (IEF) of composite materials on photo-generated carrier separation were illustrated. According to the experiments and evaluation results, the performance of BiVO4/0.6CdS is higher than CdS 2.83 times and 4.82 times under the visible light conditions, with the aspect of simultaneous oxidizing TC and reducing Cr(Ⅵ), respectively. The catalyst has a faster removal rate in the binary composite pollution system than the single one. Therefore, the photocatalytic degradation of TC using BiVO4/0.6CdS can reduce the toxic effect of TC on the environment. The aforementioned evaluation provides a new design strategy for Z-scheme heterojunction to simultaneous photocatalytic degradation of composite organic and inorganic pollutants.

Surface methyl/methylene regulates WO3 directional activation of molecular oxygen into singlet oxygen for the removal of organic pollutants in water

The efficient removal of organic pollutants using singlet oxygen (1O2) represents a pivotal advancement in environmental purification. Despite its potential, the controlled generation of 1O2 remains a challenging endeavor. In this study, we present a novel approach whereby methyl/methylene are utilized to modulate the production of 1O2 by tungsten trioxide (WO3), thereby enhancing the photocatalytic degradation of persistent pollutants through deep oxidation. Employing a dodecyltrimethylammonium bromide (DTAB)-assisted hydrothermal synthesis, we successfully fabricated WO3 capable of generating 1O2. This modified WO3 demonstrates superior performance in the photocatalytic degradation of chloroquine phosphate by facilitating the rapid separation of photo-generated electron-hole pairs, thereby accelerating the degradation process. Furthermore, WO3 augmented with 1O2 exhibits enhanced efficacy in decomposing other challenging organic contaminants, compared to its untreated counterpart. Our findings not only contribute to the advancement of photocatalytic design principles centered on 1O2 but also underscore the critical role of controlled 1O2 production in the effective eradication of pollutants.

Synthesis of near-infrared-activated YF3:Yb3+, Tm3+/Bi2MoO6 upconversion photocatalytic materials for the photocatalytic degradation of antibiotics based on fluorescence resonance energy transfer

Photocatalytic degradation of pollutants, an ecofriendly technology, is widely used for environmental remediation. However, the design and synthesis of photocatalytic materials for near-infrared light photocatalysis are challenging. In this study, an upconversion photocatalyst with fluorescence resonance energy transfer (FRET), YF3:Yb3+, Tm3+/Bi2MoO6 (YFYT/BMO), was developed and synthesised based on rare-earth upconversion luminescence. YFYT converted near-infrared (NIR) light into blue–violet light via upconversion. The rapid decay of the fluorescence lifetime of YFYT/BMO at 478 nm (Tm3+:1G4-3H6) verified that FRET efficiently occurred between YFYT and BMO. The degradation rate of tetracycline by YFYT/BMO was 2.6 times higher than that by BMO under NIR light. A great enhancement of 42.1 % on the tetracycline degradation efficiency was achieved in YFYT/BMO compared with pure BMO within 90 min of visible-NIR irradiation. This study provides a basis for developing and designing rare-earth upconversion photocatalytic materials that can achieve excellent photocatalytic degradation of antibiotics using NIR light for environmental remediation.

Ternary Composite-Enabled Photocatalytic Degradation of Multi-class Pollutants: Case Study of Congo Red, Diclofenac Sodium, and Pendimethalin

Ternary Composite-Enabled Photocatalytic Degradation of Multi-class Pollutants: Case Study of Congo Red, Diclofenac Sodium, and Pendimethalin

Photocatalytic Degradation of Maxilon Dye Pollutants using Nano‐Architecture Functional Materials: A Review

AbstractThe most essential task in the twenty‐first century is to fight the alarming growing pollution in the aquatic body in which effluent of one of the most colouring dye categories called maxilon dye is a major contributor. This review thus specifically focuses on the use of nanoparticles (NPs) for photocatalytic degradation of maxilon dye contaminants in water bodies. The work empirically presented the performance evaluation of NPs in degrading maxilon dyes under light irradiation alongside the underlying operational photocatalytic degradation mechanism. The stability of NPs was also critically analyzed by looking at the regenerability and reusability of expended NPs. From the study, it was discovered that ⋅OH and O2⋅ played a vital role in the genesis of the oxidizing capacity of NPs for the photocatalytic breakdown of maxilon dye. Moreover, it was found that the degradation performance of most NPs is greater than 80 % and the shortest degradation period is < 1 hour with pseudo‐first‐order (PFO) being the most common kinetic best‐fit to describe the adsorption process that occurred shortly before and during the degradation operation. At the end, knowledge gaps were identified in the area of regenerability, the lifecycle analyses of nano‐photocatalyst fabrication and utilization, cost analysis for industrial scale‐up, maxilon dye ecotoxicological study, and degradation pathways. The findings of this study can open up insightful innovation for readers and industries that are interested in pursuing zero water insecurity.

Construction of flake ball-shaped Bi2WO6 embedded on phenyl functionalized g-C3N4 nanosheet for efficient degradation insight of colorless pollutants and its biological application.

A facile solvent-free solid-state method was adapted to synthesize the spherical-shaped Bi2WO6 engraved on phenyl-doped g-C3N4 nanosheet, i.e., Bi2WO6/Ph-gC3N4 (or BPCN) composites with varying weights of Bi2WO6. Several spectral analyses were used to characterize all the synthesized nanomaterials. The synthesized photocatalyst showed good absorption under visible light as confirmed by UV-visible DRS analysis. Morphological analyses like SEM and TEM determine the successful fabrication of binary heterocomposite. Further, the elements available in the fabricated binary nanocomposite were confirmed by XPS. The photocatalyst was used for the aerobic photocatalytic degradation of a few colorless pollutants like bisphenol A (BPA, 30mgL-1), a microplastic constituent, and tetracycline (TC, 40mgL-1), an antibiotic derivative to achieve the impressive results. The less intense PL signal obtained for the 20BPCN heterocomposite reveals the remarkable enhancement in e--h+ pair separation and recombination rate. The quenching study, alkaline terephthalic acid photoluminescence test (TA-PL), and NBT phototransformation study explain the formation of reactive species involved in the decomposition process. An oral cancer cell line (A-254) was tested for the anticancer activity analysis of the 20BPCN photocatalyst. Based on the obtained results, a Z-scheme electron transfer mechanism has been proposed for the photodegradation of model compounds.

Fabrication of Catechol Sensitized Hollow Microspheres ZnTiO3/TiO2/ZnO for the Photodegradation of Methylene Blue

AbstractDesigning new materials that can be used to treat environmental pollutants is one of the prime focuses of chemical science. Here, an unprecedented photocatalytic material with high activity of catechol sensitized ZnTiO3/TiO2/ZnO hollow microspheres was synthesized by hydrothermal method. The structure and properties of the composite photocatalyst were analyzed by various testing methods. The photocatalytic activity was evaluated by using methylene blue (MB) as the target degradation substance. The results demonstrated that catechol (CA) sensitized ZnTiO3/TiO2/ZnO photocatalyst is a hollow microsphere with a diameter of 1–1.5 mm, the CA molecules are covalently bonded to the ZnTiO3/TiO2/ZnO surface, and the composite photocatalyst has good light absorption and carrier separation performance. Under the condition of irradiation for 90 min, the degradation rate of the composite photocatalyst for MB was higher than that of ZnTiO3/TiO2/ZnO. When the loading amount of CA was 0.6 wt%, the degradation rate of CA/ZnTiO3/TiO2/ZnO for MB was as high as 98.28 %, and the reaction rate constant was up to 4.35×10−2 min−1. A reasonable mechanism of photocatalytic degradation of pollutants by catechol as sensitizer on ZnTiO3/TiO2/ZnO was proposed. This study provides a theoretical reference for efficient photodegradation of pollutants in the environment.

Photocatalytic Degradation of Pollutants Using Advanced Ceramics: Materials, Mechanism, Synthesis, and Applications

Photocatalytic Degradation of Pollutants Using Advanced Ceramics: Materials, Mechanism, Synthesis, and Applications

Lignin-modified graphitic carbon nitride nanotubes for photocatalytic H2O2 production and degradation of brilliant black BN

As a renewable aromatic compound with enormous production potential, lignin has various potential high-value utilization pathways, but the success achieved in the field of photocatalysis is limited. Herein, this work prepares a new type of photocatalyst by modifying Graphitic Carbon Nitride Nanotubes (CNT) with self-assembled lignin nanospheres for the photocatalytic production of H2O2 and the degradation of azo dyes. Under light conditions, lignin enhances the production of H2O2 through oxygen reduction and collaborates with carbon nitride tubes to generate O2− and 1O2. Furthermore, carbon nitride tubes form electron-rich regions with lignin, promoting the transfer of electrons from adsorbed aromatic pollutants to this region, thereby facilitating their degradation. The experimental results indicate that the addition of 5 % lignin significantly enhances the photocatalytic degradation efficiency of azo dyes, with a degradation rate 1.87 times higher than that of the original carbon nitride tubes. Furthermore, CNL also have excellent degradation ability to pollutants in actual wastewater. This study provides new insights and prospects for the high-value utilization of lignin, enabling it to be used as a photocatalytic co-catalyst to participate in the photocatalytic degradation of environmental pollutants.

Recent Developments in Porphyrin-Based Metal-Organic Framework Materials for Water Remediation under Visible-Light Irradiation.

Access to clean drinking water is a basic requirement, and eliminating pollutants from wastewater is important for saving water ecosystems. The porous structure and surface characteristics of metal-organic frameworks (MOFs) can function as a perfect scaffold for removing toxic compounds from wastewater. Porphyrins are promising building blocks for constructing MOFs. Porphyrin-based metal-organic frameworks (P-MOFs) have been fabricated using porphyrin ligands, metal clusters, or ions. These materials can harvest light from a wide region of the solar spectrum, and their framework morphology and physicochemical properties can be controlled by changing their peripheral subunits or metal ions. These porous crystalline materials have generated interest because of their distinctive characteristics, including large permanent porosity, interesting surface morphology, broad conformational diversity, high photostability, and semiconducting nature. This article discusses the recent progress and usefulness of P-MOFs. The fabrication procedures of P-MOFs are discussed, followed by the adsorptive and photocatalytic removal of contaminants from wastewater. The relationships between the geometries of P-MOFs and their light-harvesting and charge-transfer mechanisms for the photocatalytic degradation of pollutants are highlighted. Finally, some future perspectives and obstacles in the photodegradation usage of P-MOFs are discussed, along with feasible research directions to standardize efficient photocatalysts for improved photodegradation for water treatment.

Fabrication of Ag-decorated La0.9Ag0.1FeO3 for efficient photocatalytic degradation of tetracycline under visible light with the assistance of water oxidation

The photocatalytic conversion of molecular O2 into reactive oxygen species, such as superoxide radicals (·O2-), has become the focus in the oxidative removal of organic pollutants. Nevertheless, the inefficient light absorption, limited adsorption of O2, and the fast recombination rate of photo-induced electron-hole pairs considerably impede the conversion efficiency of the photocatalysts. Herein, we report the synthesis of Ag@LAFO photocatalyst, which contains Ag nanoparticles (NPs)-decorated LAFO (Ag-substituted LaFeO3), to enhance the photodegradation efficiency of tetracycline (TC) with the assistance of water oxidation. Structural and spectroscopic analyses confirmed the successful decoration of Ag NPs on LAFO, which was prepared by substituting 10 % La with Ag. The efficiency of TC photocatalytic degradation rate of Ag@LAFO is 76.25 %, which is 6.1-fold higher than that of pure LFO (12.41 %). The trapping experiment of active radicals verified that ·O2- was crucial in the decomposition of TC molecules and was continuously supplied by the reduction of O2 molecules supported by photocatalytic water oxidation. Moreover, the Ag NPs in Ag@LAFO were found to be crucial for boosting the capture of photo-induced electrons and the activation of adsorbed O2. This study offers a new perspective on the conversion of O2 to ·O2- with the assistance of photocatalytic water oxidation for photocatalytic degradation of organic pollutants.

Constructing a type-II heterojunction of AgI/CO32−-Bi2O2CO3 for enhanced photocatalytic degradation of organic pollutants

The construction of heterojunctions is a well-established approach for enhancing the photocatalytic efficiency of semiconductor materials. To improve the photocatalytic activity of CO32−-Bi2O2CO3, AgI/CO32−-Bi2O2CO3 type-II heterojunction photocatalysts were synthesized using an electrostatic self-assembly method with varying composite ratios. The performance of AgI/CO32−-Bi2O2CO3 catalyst was investigated by photocatalytic degradation of 2-Hydroxy-1, 4-naphthoquinone and levofloxacin under a 300 W xenon lamp (λ ≥ 420 nm). The results demonstrated that the composite photocatalyst (0.5ACBOC), prepared by incorporating 0.5 mL of AgNO3 and KI, exhibited exceptional photocurrent responsiveness and efficient charge carrier separation. 0.5ACBOC displayed the highest degradation efficiency towards 2-Hydroxy-1,4-naphthoquinone (67.5%) and levofloxacin (78.0%). Free radical capture experiments and electron paramagnetic resonance (EPR) analysis revealed ·O2− as a crucial reactive species in the photodegradation process. Moreover, the photocatalytic degradation of 2-Hydroxy-1,4-naphthoquinone exhibited consistent removal efficiency even after undergoing four cycles, thereby demonstrating the excellent cycle stability of the composite catalyst. These findings highlight that AgI/CO32−-Bi2O2CO3 can be easily synthesized and holds great potential as a photocatalyst for efficient degradation of organic pollutants.

S-Schematic CuWO4/ZnO nanocomposite boosted photocatalytic degradation of organic dye pollutants

S-schematic CuWO4/ZnO nanocomposite photocatalyst was synthesized by an impregnation method. Synthesized CuWO4 and ZnO nanoparticles, and CuWO4/ZnO nanocomposites were thoroughly characterized. X-ray diffraction (XRD) analysis of the CuWO4/ZnO nanocomposite confirmed the respective triclinic and hexagonal wurtzite structures of CuWO4 and ZnO crystals. Raman and Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectroscopy (XPS) revealed bond formations in CuWO4 and ZnO, and confirmed the synthesis of the CuWO4/ZnO nanocomposite. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed CuWO4 nanoparticles adhered to ZnO aggregates. Energy dispersive X-ray spectrometry (EDS) confirmed the distribution of CuWO4 on the ZnO aggregates. UV–Vis diffuse reflectance spectroscopy (DRS) showed optical bandgap energies of 2.36 eV for CuWO4 and 3.18 eV for ZnO nanoparticles. The photocatalytic performance of the CuWO4/ZnO nanocomposite was investigated through the degradation of the cationic dyes methylene blue (MB) and Rhodamine B (RhB) and the anionic dye methyl orange (MO). A 5.0%CuWO4/ZnO nanocomposite degraded 100% of MB within 120 min, 91.02% of RhB within 300 min, and 89.13% of MO within 300 min. The pseudo-first order kinetic rate constant fit well for the degradation of all the dyes on the CuWO4/ZnO nanocomposite. The CuWO4/ZnO nanocomposite could better degrade the cationic dyes than the anionic dye in an aqueous solution. The hole (h+), the hydroxyl radical (•OH), and the superoxide ion (•O2−) were the active species responsible for degrading MB, RhB and MO dyes. The proposed CuWO4/ZnO nanocomposite could be applied for environment friendly wastewater treatment.