Efficient Photocatalytic Removal Research Articles

Enhanced adsorption and visible-light photocatalytic degradation of CIP by CdS QDs‐Decorated Mn-doped NH2-UiO-66

CdS Quantum dots (QDs) interspersed on the surface of Mn-UiO-66-NH2 (hereafter abbreviated as CdS QDs@Mn-UiO-66-NH2) Z-scheme heterojunction composites were synthesized by solvothermal method for the removal of ciprofloxacin (CIP) under visible light irradiation. The influences of the doping content of Mn and the initial concentrations of CIP on the adsorption capacity and photocatalytic performance were investigated in detail. Compared to the pristine CdS and Mn-UiO-66-NH2, the fabricated CdS QDs@Mn-UiO-66-NH2 composites exhibited enhanced adsorption and photocatalytic capabilities, especially for the CMU-5 with 10 % Mn doping showing around 52.5 % adsorption removal efficiency and about 92 % photocatalytic removal efficiency for CIP (30 mg/L). Various technologies such as XPS, TG and UV–vis DRS have confirmed that the superior catalytic performance of CMU-5 is ascribed to the d-d transitions improving the utilization of visible light after the coordination of the transition metal and the presence of a heterojunction with a tight interfacial structure enhancing the charge transfer. The possible intermediates in the photodegradation process of CIP were detected using gas chromatography-mass spectrometry (GC-MS).

Engineering the defect distribution via boron doping in amorphous TiO2 for robust photocatalytic NO removal

Nitric oxide (NO) pollutant can threaten the regional environment and human health. Solar-powered photocatalytic oxidation method is desirable for NO removal (ppb level) at ambient conditions, but suffers from the unsatisfactory activity and poor selectivity due to the sluggish molecular oxygen activation. Herein, we demonstrate that efficient photocatalytic NO removal can be realized by modulating the defects distribution of amorphous TiO2 via boron doping. Theoretical calculations and experimental results reveal that H3BO3 modification can refine the structure of surface oxygen vacancies, promoting electron-rich molecular oxygen activation to •OH. Meanwhile, bulk-phase oxygen defects can be filled by free-state B atoms, accelerating the electron transfer via Ti-O-B bonding. Homogeneous boron-doped amorphous TiO2 achieves about 5 times higher NO removal efficiency (∼50%) than that of amorphous TiO2 (∼9%) without releasing remarkable NO2 (selectivity, ∼97%). This study provides a state-of-the-art approach for robust photocatalytic NO removal by engineering the defect distribution.

Tailored transition metal-doped TiO2@Fe3O4 nanohybrids for efficient photocatalytic dye removal: Optimization via neural networks and response surface approaches

The study focused on predicting the degradation of Remazol Turquoise Blue (RTB) dye using a photocatalyst comprised of transition metal-doped TiO2@Fe3O4. Out of the transition metal ions considered, namely Cu, Cr, Co, and Ni, Cr emerges as the most effective dopant for TiO2@Fe3O4 nanohybrid photocatalysts. This optimal performance was achieved with a catalyst loading of 50 mg and a dye concentration of 10 ppm within a 1-h reaction time, resulting in a photocatalytic efficiency of 96.70%. The optimization strategy employed a combination of Response Surface Methodology (RSM) and Artificial Neural Networks (ANN). To conduct experiments systematically, a Box-Behnken Design (BBD) rooted in RSM principles was utilized to create experimental setups for the photocatalytic degradation of the dye with the doped photocatalyst. The variables such as reaction time, catalyst dosage and dye concentration were designed to optimize the RTB dye degradation. The Regression coefficient (R2) for the developed RSM and ANN models were found to be 0.9299 and 0.9925 respectively, and revealed that the ANN has higher prediction capability and accuracy than other model. The outcomes underlined that the dosage of the catalyst prominently emerged as the principal determinant governing the efficacy of the photocatalytic activity. Remarkably, the Cr doped TiO2@Fe3O4 photocatalyst maintained its activity through six degradation cycles, with efficiencies of 99.7%, 99.4%, 99.1%, 88.8%, 87.3%, and 86.3%, respectively.

Z-Scheme heterojunction Cu2(OH)3F/Bi2WO6 with improved photocatalytic activity for uranium removal from wastewater under air atmosphere

The proper treatment of uranium-contaminated nuclear wastewater is important for uranium resource recovery and environmental protection. Photocatalytic strategies have emerged as promising approaches for improving uranium removal efficiency. In this study, a Z-scheme heterojunction Cu2(OH)3F/Bi2WO6 (CFO/BWO) was synthesized by directly depositing CFO onto a BWO semiconductor for highly efficient photocatalytic removal of uranium from wastewater. The CFO semiconductor contains abundant O–H bonds and a high conduction band position, which can couple with BWO to form a heterojunction via interactions between the O and W atoms. Owing to the high electronegativity of CFO, electrons easily transfer from BWO to CFO, resulting in enhanced electron-hole separation and promoted electron transmission. Importantly, introducing CFO narrowed the bandgap of CFO/BWO compared to that of BWO, providing an appropriate band position, which is more conducive to the photocatalytic immobilization of uranium. Moreover, the mechanism of CFO/BWO heterojunction for photocatalytic immobilization of uranium revealed the formation of a stable crystalline phase of (UO2)O2·2H2O during the photocatalytic process. As a result, CFO/BWO could remove 91 % of uranium from simulated wastewater under an air atmosphere. The findings of this study provide a promising strategy by regulating the band position of heterojunctions for photocatalytic immobilization of uranium.

A novel peony-shaped ZnO/biochar nanocomposites with dominant {100} facets for efficient adsorption and photocatalytic removal of refractory contaminants

Herein, a peony-shaped nanocomposite (P-ZnO/BC) was facilely developed by incorporating ZnO with Hemp stalk derived biochar (BC) via two-step sequential solvothermal procedure and used for photocatalytic degradation of organic contaminants. The as-prepared P-ZnO/BC presents preferential (100) crystal orientation, suitable electronic energy level, and distinct mesoporous distribution as well as large specific surface area. Thereby, the optimal P-ZnO0.3/BC (weight ratio of 3:7 for ZnO:BC) shows higher photocatalytic activity with degradation efficiency as high as 94.5 % toward methylene blue (MB) within 120 min, whereas the ZnO and BC merely deliver 6.3 % and 63.5 %, respectively. Obviously, the superior contaminants removal properties of P-ZnO0.3/BC can be attributed to the synergistic effect of adsorption of BC and photocatalysis of ZnO. Also, this can be associated with the improved adsorption, accelerated charges (e-/h+ pairs) transportation and reduced e-/h+ pairs recombination of P-ZnO0.3/BC. The reactive radicals scavenging experiments and ESR measurements confirm that the main reactive species are hydroxyl radicals (•OH) and holes (h+). Furthermore, P-ZnO0.3/BC displays desirable reusability and better universal applicability toward other organic dyes and antibiotics removal. Moreover, the possible degradation mechanism and pathway were also inferred by analyzing the intermediates via liquid chromatography mass spectrometry (LC-MS) technique. In conclusion, this work provides a fundamental insight via integrating ZnO with low-cost BC for efficient removal of the refractory organic pollutants.

In situ construction of N-rich carbon nitride (C3N5)/silver phosphate (Ag3PO4) S-scheme heterojunctions for the efficient photocatalytic removal of levofloxacin antibiotic and RhB

In situ construction of N-rich carbon nitride (C3N5)/silver phosphate (Ag3PO4) S-scheme heterojunctions for the efficient photocatalytic removal of levofloxacin antibiotic and RhB

Atomically dispersed magnesium enhancing reactive oxygen species generation over g-C3N4 nanosheets for efficient photocatalytic NO removal

Photoinduced reactive oxygen species (ROSs)-involving nitrogen oxide (NOx) abatement offers a green way to mitigate environmental air pollution. Developing cost-effective photocatalysts remains challenging yet crucial. Herein, an atomically dispersed Mg-modified g-C3N4 nanosheet photocatalyst (xMg-CN) with excellent photoactivity is developed. The 1.0Mg-CN sample delivers a high NO removal rate of 52.3% under visible light irradiation within 30 min, far surpassing the Mg-free analog (CN, 41.2%). Moreover, a suppressed NO2 by-product discharge can be achieved. The introduction of Mg single atoms (SAs) alters the charge density distribution on the triazine ring plane of g-C3N4, inducing the formation of a built-in electric field, which improves the photoexcited charge carrier separation. Additionally, Mg SAs contribute to the adsorption and activation of O2 molecules, resulting in enhanced ROSs production, as evidenced by the experiments and theoretical simulations. The findings shed light on the role of SAs in designing highly efficient g-C3N4-based photocatalysts for air purification.

Engineering a staggered type-II Bi2WO6/WO3 heterojunction with improved photocatalytic activity in wastewater treatment

In recent years, the removal organic pollutants from wastewater by advanced oxidation processes, especially photocatalysis, has become a meaningful approach due to its eco-friendliness and low cost. Herein, staggered type-II Bi2WO6/WO3 heterojunction photocatalysts were prepared by a facile hydrothermal route and investigated by modern physicochemical methods (X-ray diffraction, scanning electron microscopy, low-temperature nitrogen adsorption-desorption, and diffuse reflectance spectroscopy). The optimized BWOW-5 photocatalyst exhibited a H2O2-assisted photocatalytic methylene blue removal efficiency of 94.1% (k = 0.01414 min−1) within 180 min under optimal reaction conditions, which is much higher than that of unmodified Bi2WO6 and WO3 due to efficient separation of the photogenerated charge carriers. The trapping experiments demonstrated that photogenerated hydroxyl radicals and holes play a key role in the photodegradation reaction. Moreover, the optimized BWOW-5 heterojunction photocatalyst exhibited excellent activity in the H2O2-assisted degradation of other pollutants, namely phenol, isoniazid, levofloxacin, and dibenzothiophene with the removal rate of 63.1, 73.6, 95.0, and 72.4%, respectively. This investigation offers a design strategy for Bi2WO6-based multifunctional photocatalytic composites with improved activity for organic pollutant degradation.

Anatase TiO2/Defective UiO-66 porous octahedral S-scheme heterojunctions toward optimized photocatalytic performance

Photocatalysis is an alternative for antibiotics removal from wastewater for the sustainable development of human society. However, applying photocatalysts for antibiotics (e.g., tetracycline) degradation under practical conditions is highly restricted by the low reaction efficiency due to the prompt charge recombination. Constructing porous heterojunctions is an efficient way to regulate the electron transfer path and accelerate charge migration efficiency. Herein, TiO2/defective UiO-66 porous octahedral S-scheme heterojunctions are successfully fabricated through an in-situ growth strategy. The strong interaction and charge migration behavior between TiO2 and defective UiO-66 have been studied using X-ray photoelectron spectroscopy and electron paramagnetic resonance measurements. The photocatalytic removal efficiency of tetracycline is notably improved by forming TiO2/defective UiO-66 porous heterojunctions. The promoted photocatalytic performance can be ascribed to the strong interaction between TiO2 and defective UiO-66, and the accelerated charge separation and transfer efficiency due to the formation of S-scheme heterojunctions, thus generating abundant reactive oxygen species, including O2− and OH. The optimized 38-TiO2/UiO-66-300 can eliminate 97.9 % of tetracycline in 60 min with a reaction constant rate of 0.0425 min−1, which is approximately 4 and 10 times that of pristine TiO2 and UiO-66-300, respectively. This work provides an alternate strategy for preparing highly active heterojunction photocatalysts for environmental applications.

Constructing multiple active sites of Bi2WO6 for efficient photocatalytic NO removal and NO2 inhibition

Insufficient photocatalytic NOx oxidation capacity will lead to excessive toxic by-products (NO2), which still seriously restrict its practical application. Herein, the multiple active sites (Cl, Bi0 and OVs) modified Bi2WO6 has been established by in-situ synthesis method. The synergistic effect of multiple active sites greatly increased the photo-electric properties of the Bi2WO6, resulting in the boosting photocatalytic NOx deep oxidation to nitrate. The visible light driven OVs-Bi@BWO-Cl catalyst exhibited a highest NO conversion efficiency (67.3 %) with extremely low NO2 concentration (17.9 ppb). The synergism of structural regulation from the OVs with Cl-doping and surface plasmon resonance of Bi0 significantly enhanced light absorption and provided a fast charge transport channel, improving the separation efficiency of photo-generated carriers. The in-situ DRIFTS and density functional theory (DFT) results shown that the synergistic effect by multiple active sites could enhance the adsorption and activation of reactants to accelerate the processes of H2O/O2-to-ROS and decrease the energy barrier of NO removal to promote deep oxidation of NO-to-NO3−. This work can provide ideas for the design and preparation of the catalyst for safe photocatalytic environment purification.

Efficient photocatalytic removal of ciprofloxacin through in-situ growth of g-C3N4 on the surface of clinoptilolite

Natural mineral clinoptilolite has many advantages such as porous structure, stability, low price, environmental protection, and simple modification process, making it an ideal choice for wastewater treatment materials. Loading photocatalysts on the surface of zeolite can effectively exert adsorption degradation synergy in wastewater treatment, improve pollutant removal and mineralization capabilities, and further reduce the harm of wastewater to the environment. In this work, g-C3N4 was in-situ grown on the surface of clinoptilolite using a one-step calcination method for efficient photocatalytic removal of the pollutant ciprofloxacin from water. In-situ growth of g-C3N4 on clinoptilolite enables the catalyst to have strong adsorption capacity for pollutants. At the same time, the large specific surface area and extended photo-generated carrier lifetime make the composite photocatalyst exhibit excellent visible light adsorption degradation ability. The CN/CLI-60 with the best photocatalytic performance showed a removal rate of over 90 % of ciprofloxacin within 60 min, much higher than pure g-C3N4 and clinoptilolite. In addition, the pH value, pollutant concentration, catalyst quantity, and cycle stability have all been investigated to evaluate the practical application potential of this catalyst. This work can provide industrial guidance for the rational design of low-cost and high-efficiency photocatalysts using natural clinoptilolite.

Ternary heterojunction of cross-linked benzene Polymer/Bi2MoO6-Graphene oxide catalysts promote efficient adsorption and photocatalytic removal of oxytetracycline

Antibiotics are refractory degradable organic pollutants that present a significant hazard to water environments. In this work, a ternary composite (KB/BMO-GO) comprising of graphene oxide (GO), Bi2MoO6 (BMO), and a cross-linked benzene polymer (KB) was synthesized and applied to promote the synergistic adsorption-photocatalytic degradation of the refractory pollutant, oxytetracycline (OTC). The inclusion of GO and KB in the composite enhanced the OTC adsorption performance of the catalysts, and the construction of Z-scheme heterojunction promoted the photogenerated charge separation efficiency and broadened the range of light absorption, thereby enhancing the photocatalytic performance. Moreover, we compared the performance of catalysts loaded with different mass ratios of KB (x% KB/BMO-GO). Among them, the 15 % KB/BMO-GO catalyst sample had the best OTC degradation performance. Specifically, 15 % KB/BMO-GO could adsorb 69.7 % of OTC in 30 min, reaching an OTC degradation rate of 93.3 % under visible light irradiation. h+ and 1O2 are the main active substances in the photocatalytic process. In addition, the catalysts are acid-alkali and salt-resistant, as well as good reusability. This study provides a valuable reference for the preparation of highly efficient photocatalysts for synergistic adsorption-photodegradation processes.

A novel annulated dinuclear dizinc phthalocyanine cross-linked h-BN polyamides for efficient photocatalytic levofloxacin removal from real pharmaceutical wastewater

The alignment of the strong visible-light harvesting phthalocyanine and its metal derivatives onto wide-gap semiconductors has been recognized as a bright approach to fabricate highly effective photocatalysts for energy conversation and environmental restoration. However, the practical application of phthalocyanine-sensitized photocatalysts depends on their incorporation mode between phthalocyanine and basic materials. In this work, a novel high-effective dinuclear zinc (II) phthalocyanine-sensitized photocatalyst is fabricated via covalent immobilization of (Bis(82,112,152-tri-(6-oxyl-2-carboxyl)-naphthaoxytribenzo)[g,l,q]-5,10,15,20-tetraazaporphrinno[b,e]benzene) dizinc (II), (ZnTcPc)2 onto the amino functionalized hexagonal boron nitride (–NH2-h-BN) nanosheets for the first time by a facile condensation strategy. The optimized 9%(ZnTcPc)2/h-BN polymer displays remarkably improved photocatalytic activity in levofloxacin degradation from different aqueous solutions with long-term stability under visible-light illumination. Its decomposition rates reach 81.4%, 71.7% and 90.8% in deionized water, tap water and real pharmaceutical wastewater, respectively. It is approximately 7 times than that of bare h-BN nanosheets in deionized water. The detailed experimental data indicate that the critical role of for improving visible-light harvesting and photoinduced electron transfer capability of h-BN acted by the strongly chemical bond constructed between (ZnTcPc)2 and –NH2-h-BN. The improved photocatalytic mechanism for levofloxacin removal over 9%(ZnTcPc)2/h-BN polymer is proposed according to the results of ESR, UV–vis and fluorescence measurements. Therefore, this unique combination approach affords a carefully designed molecular photocatalyst with great potential application in environmental remediation.

Enhanced interfacial effect via acid theory with boosted photocatalytic performance of nitenpyram removal

Surface reaction is a prominent aspect that affects the efficiency of photocatalysis. In this work, acid theory was employed to facilitate the reaction dynamics and enhance the interfacial effect between photocatalysts and target molecules. The photocatalytic removal efficiency of NTP was 66 % for bare CdS in 50 min with apparent rate constants of 0.023 compare to 96 % with apparent rate constants of 0.065 for 5% Ce–CdS. The introduced Ce atom as bifunctional active site reduces the energy barrier of O2 adsorption, strengthens the interfacial effect and accelerates the electrons transfer, which could facilitate surface reaction process and boost the photocatalytic performance.

An organic/inorganic Z-scheme heterojunction Yb-MOF/BiOBr for efficient photocatalytic removal of NO

The advantages of visible light-driven catalysts with good light absorption, fast charge separation rate and high redox capacity are compelling. However, conventional inorganic semiconductor, such as pure BiOBr (BOB), showed a rapid photogenerated carriers recombination rate and low solar energy utilization ability, which limited the practical application of its photocatalytic performance. In this work, a novel organic/inorganic interleaved (Z-scheme) heterojunction Yb-MOF/BiOBr (Yb-MOF/BOB) photocatalyst was successfully synthesized. Compared with a single component, the Yb-MOF/BOB heterojunction exhibited significantly enhanced performance in photocatalytic oxidation of NO under visible light. Among them, Yb-MOF/BOB-20 had the best photocatalytic NO removal effect, up to 6424 ppb/g, which was 2.8 times and 4.2 times that of BOB and Yb-MOF, respectively. Photoelectrochemical characterization confirmed that the formation of heterojunctions broadened the absorption sidebands and increased the charge transfer at the interfacial junction of Yb-MOF/BOB. Combined with UPS, ESR and in-situ DRIFTS analysis, possible photocatalytic mechanisms were revealed, in which the formation of the Yb-MOF/BOB heterostructure endowed its high charge mobility and strong redox ability. Therefore, this work provided an effective way for photocatalytic removal of NO, and offered new ideas for developing heterogeneous photocatalysts.

3D-printed Al2O3 framework supported carbon-bridged tri-s-triazine of g-C3N4 for photocatalytic tetracycline oxidation

Powder-like g-C3N4 has been widely used as a photocatalyst but exhibits several drawbacks, including unrecyclable, high charge recombination, and limited light absorption. In this study, carbon-bridged g-C3N4 was successfully prepared and coated on a 3D-printed Al2O3 substrate for the photocatalytic oxidation of tetracycline. Oxamide (OD), malonamide (MD), and succinamide (SD) were used as carbon-containing linkers to react with precursors (melamine and urea) and produce carbon-bridged g-C3N4. Carbon substitution at the bridged N atoms of g-C3N4 improved light absorption, reduced charge recombination, and resulted in high photocatalytic tetracycline removal efficiency. Computational calculations were also employed, and Bader charge analysis supported the charge redistribution and charge transfer of the carbon-bridged g-C3N4 samples. Our results indicated that the degradation of tetracycline followed step-by-step oxidation, deamination, and mineralization to form CO2 and H2O. The 3D-printed Al2O3-supported carbon-bridged g-C3N4 exhibited a high removal rate of 85–90 % and stability for photocatalytic reactions and can be reused for at least 10 cycles. This study demonstrates that the 3D-printed Al2O3-supported carbon-bridged g-C3N4 catalyst is an efficient and effective catalyst support system for photocatalytic reactions.

Synthesis of Novel MOF‐Based BixTiy‐BTC and Bi1Ti3‐BTC/Fe3O4 Photocatalysts and Their Application in the Degradation of UDMH in Wastewater

AbstractRemoval of organic pollutants from wastewater remains a significant challenge. Hence, we report a series of novel MOFs based BixTiy‐BTC photocatalysts synthesized by hydrothermal method for decontamination of 1,1‐Dimethylhydrazine (UDMH). The preparation parameters of MOFs were optimized, the best catalytic performance was achieved by adjusting the Bi/Ti molar ratio to 1 : 3, with Bi1Ti3‐BTC a photocurrent density of 0.35 mA/cm2 was reached. The morphology and composition of the materials were analyzed, titanium doping increased the specific surface area. Bi1Ti3‐BTC was loaded with magnetic nano‐Fe3O4, which prevented agglomeration of Bi1Ti3‐BTC and increased the specific surface area, thus improving photocatalytic activity. The band gap structure of the semiconductor materials was estimated by UV‐Vis and XPS valence band spectra, while the separation efficiency of photogenerated carriers was investigated by photocurrent density and PL (Photoluminescence) spectrum. The photocatalytic degradation rate of UDMH rapidly decreased after addition of EDTA, indicating that h+ was the main active species in the photocatalytic degradation process. The photocatalytic removal efficiency of UDMH with Bi1Ti3‐BTC/Fe3O4 at a concentration of 0.5 g/L reached 97.58 % after illumination for 180 min, and after 210 min near quantitative degradation was observed.

High performance Co3O4/Sn-ZnO nanocomposite photocatalyst for removal of methylene blue dye

Methylene blue is a toxic, carcinogenic, and non-biodegradable synthetic dye discharged from factories and industries that causes severe harm to human health and environmental pollution. Therefore, in this work, Co3O4/Sn-ZnO nanocomposite was synthesized using a simple sol–gel method for efficient photocatalytic removal of methylene blue dye in an aqueous basic medium. The structural, optical, photoluminescence, morphological, and compositional properties were studied. The XRD result revealed that the crystal size increases as the full width at half maxima (FWHM) decreases when Co3O4 are coupled with Sn-ZnO. From UV-visible diffusive reflectance and photoluminescence spectroscopies, a narrowing of the band gap and a reduction of the charge carrier’s recombination rate were observed, respectively. The photocatalytic efficiency and degradation rate constant of 95.1% and 0.03251 min−1 were recorded for methylene blue dye upon the use of optimized catalyst dosage of 60 mg Co3O4/Sn-ZnO nanocomposite catalyst under an irradiation time of 100 min at room temperature for optimized pH value of 9 in an aqueous basic medium.

One-step in-situ construction engineering of ZnO-Zn2SnO4 heterojunction for deeply photocatalytic oxidation of nitric oxide

The generation of hazardous intermediates during the process of photocatalytic nitric oxide (NO) oxidation presents a tough issue. Herein, a one-step microwave strategy was employed to introduce oxygen vacancies (OVs) into zinc oxide-zinc stannate (ZnO-Zn2SnO4) heterojunction, resulting in an improvement in the photocatalytic efficiency for NO removal. The construction ZnO-Zn2SnO4 heterojunction with the OVs (ZSO-3) owns a significant contribution towards highly efficient electron transfer efficiency (99.7%), which renders ZSO-3 to exert a deep oxidation of NO-to-nitrate (NO3−) rather than NO-to-nitrite (NO2−) or NO-to-nitrogen dioxide (NO2). Based on the solid supports of experimental and simulated calculations, it can be found that OVs play an irreplaceable role in activating small molecules such as NO and O2. Moreover, the enhanced adsorption capacity of small molecules, which guarantees the high yield of active radical due to the formation of S-scheme heterojunction. This work illuminates a novel viewpoint on one-step in-situ route to prepare Zn2SnO4-based heterojunction photocatalyst with deep oxidation ability of NO-to-NO3−.

SiO2/WO3/ZnO based self-cleaning coatings for solar cells

The accumulation of pollution and any kinds of contamination on the glass cover of the solar cell affects the efficiency of the photovoltaic (PV) systems. The contamination on the glass cover can absorb and reflect a certain part of the sunlight irradiation, which can decrease the intensity of the light coming in through the glass cover. With the study, it was planned to develop self-cleaning coatings for the PV systems. It was aimed to prevent or reduce the contamination-induced efficiency loss of the existing PV systems. In the scope of the project, SiO2/WO3 and SiO2/WO3/ZnO composites were coated from their solutions on the glass substrates using a dip-coating technique. WO3 was selected as a photocatalyst semiconductor. Under the UV light irradiation, WO3 could absorb the photons of the UV light, generating the photoinduced charge carriers. The photoexcited charge carriers provide both the photoinduced hydrophilicity on the surface of the coating and the photocatalytic degradation of the organic contaminants accumulated on the surface of the coating, which allows water droplets to spread and flow on the surface of the cover glass to remove the contaminations. However, the recombination rate of the photoexcited charge carriers on the WO3 film was high. In order to suppress the recombination of the photoinduced charge carriers, WO3 was coupled with SiO2 and ZnO. Both of these semiconductors improved the photocatalytic activity of the WO3 film. Although SiO2 has superior features in terms of the light transmission, it was not very effective under UV light as a photocatalyst alone. The widely preferred photocatalyst ZnO was added into the composite film structure to enhance the photocatalytic activity. The self-cleaning mechanism of the film coatings on a solar cell was investigated through the photocatalytic dye removal efficiency on the as-prepared film samples. There was a slight decrease in the light transparency and the solar cell efficiency because of the WO3 content of the composite film. On the other hand, coupling the SiO2/WO3 film with ZnO enhanced the photocatalytic activity, and it suppressed the reduction effect of the WO3 phase on both the light transparency and the solar cell efficiency. The photocatalytic dye removal efficiency was increased to over 90% after 240 min of UVA light irradiation. In addition, the solar cell coated with the SiO2/WO3/ZnO film provided almost the same solar cell efficiency as the uncoated solar cell. The water contact angle measurement also exhibited the photocatalytic degradation of the model contamination on the glass cover of the solar cell under the UVA light irradiation.Graphical