Photodegradation Mechanism Research Articles

SnO2 nanoparticles embedded onto MoS2 nanoflakes - An efficient catalyst for photodegradation of methylene blue and photoreduction of hexavalent chromium

In this work, a molybdenum disulfide/tin oxide (MoS2/SnO2) composite was successfully prepared via a hydrothermal method. The MoS2/SnO2 composite was used as a photocatalyst for photoreduction of hexavalent chromium and photodecomposition of methylene blue. It exhibited higher photocatalytic performance under simulated solar light irradiation than MoS2 itself. The obtained material was characterized by several spectroscopic and microscopic techniques, namely X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). TEM images of the MoS2/SnO2 revealed that SnO2 nanoparticles were embedded into MoS2. Furthermore, photodegradation mechanism and the role of adsorption were discussed. The enhanced photocatalytic performance of MoS2/SnO2 composite can be directly attributed to the presence of SnO2, which may increase the separation efficiency of the electron-hole pairs. The 99.5% of MB removal was achieved after 5 minutes of illumination. To the best of our knowledge, it is one of the most photoactive MoS2-based photocatalysts for methylene blue (MB) photodecomposition. Moreover, the obtained composite was highly active against chromium (VI) photo-reduction. This work provides evidence that the MoS2/SnO2 composite possesses enormous potential in photocatalytic applications.

Changing the optical properties of poly(methyl methacrylate) superficial films during UV irradiation

In this work, the simple spectroscopic method is presented to study the change of the optical constants n and k of the poly(methyl methacrylate), UV-irradiated. The infrared reflection-absorption spectra were recorded at a single incidence angle. The reflection-absorption spectra of the poly(methyl methacrylate) thin films were processed using classical dispersion analysis and a fitting program to obtain optical constants n and k. The shift, the variation of intensity, or broadening of the absorption bands during the UV degradation, were watched in the extinction coefficient k spectrum. The changes in the extinction spectrum of UV-irradiated polymer films are consistent with the photodegradation mechanisms described in the literature.

Facile synthesis of C–Ta4+ co-doped NaTaO3 and rGO nanocomposites with enhanced visible light photocatalytic performance

Nanocomposites of C–Ta4+ co-doped NaTaO3 and reduced graphene oxide (C-NTO/rGO) with highly efficient photocatalytic activity were fabricated by a one-step solvothermal reaction. The optimum composites C-NTO/3rGO (with 3 wt% rGO) exhibited superior photocatalytic activity for the degradation of RhB over a mono-component counterpart under visible light irradiation. The photocatalytic efficiency was found to be as high as 97% for 90 min. Both XRD and XPS characterizations indicated that the doping of carbon into the NaTaO3 lattice leads to the reduction of Ta5+ to Ta4+. Furthermore, the co-doping significantly narrows the band gap (about 2.8 eV). Photo-luminescence (PL), time resolved transient PL decay spectra and photo-current results confirmed that photo-induced hole-electron pairs can be effectively separated resulting from the introduction of rGO. The synergistic effect of a decreased band gap and highly effective separation of photo-generated electrons and holes may be responsible for the enhanced photocatalytic activity of the fabricated nanocomposites. Both h+ and •OH active radicals were found to be the key factors for the photo-decomposition process of RhB over the nanocomposites, while •O2− was also involved to a smaller extent. A possible photo-degradation mechanism for C-NTO/rGO was proposed on the basis of the experiments results.

Enhanced Photo-Fenton Activity of SnO2/α-Fe2O3 Composites Prepared by a Two-Step Solvothermal Method

The x-SnO2/α-Fe2O3 (x = 0.04, 0.07, and 0.1) heterogeneous composites were successfully prepared via a two-step solvothermal method. These composites were systematically characterized by the X-ray diffraction technique, field emission scanning electron microscopy, an energy dispersive spectrometer, X-ray photoelectron spectroscopy and a UV–visible spectrometer. It was found that SnO2 nanoparticles were uniformly decorated on the surface of α-Fe2O3 particles in these heterogeneous composites. A comparative study of methylene blue (MB) photodegradation by α-Fe2O3 and x-SnO2/α-Fe2O3 composites was carried out. All x-SnO2/α-Fe2O3 composites showed higher MB photodegradation efficiency than α-Fe2O3. When x = 0.07, the MB photodegradation efficiency can reach 97% in 60 min. Meanwhile, the first-order kinetic studies demonstrated that the optimal rate constant of 0.07-SnO2/α-Fe2O3 composite was 0.0537 min−1, while that of pure α-Fe2O3 was only 0.0191 min−1. The catalytic mechanism of MB photodegradation by SnO2/α-Fe2O3 was examined. The SnO2 can act as a sink and help the effective transfer of photo-generated electrons for decomposing hydrogen peroxide (H2O2) into active radicals. This work can provide a new insight into the catalytic mechanism of the photo-Fenton process.

Synergistic Generation of Radicals by Formic Acid/H2O2/g-C3N4 Nanosheets for Ultra-efficient Oxidative Photodegradation of Rhodamine B

Water pollution is a global challenge endangering people's health. In this work, an ultra-efficient photodegradation system of Rhodamine B (RhB) has been established using a graphitic carbon nitride nanosheet (CNNS) as the semiconductor photocatalyst, from which energy is harvested on both the conduction band and valence band by formic acid and hydrogen peroxide, respectively. The optimized FA/H2O2/CNNS system increases the apparent photodegradation rate of RhB by 25 folds, from 0.0198 to 0.4975 min-1. Through a comprehensive investigation with reactive oxygen species scavengers, electron paramagnetic resonance, high-performance liquid chromatography-mass spectrometry, etc., an oxidative mechanism for RhB photodegradation has been proposed, which combines enhanced charge carrier migration and synergistic generation of multiple radicals. Comparable performance improvements have also been observed for similar systems with different semiconductors, suggesting that such a catalytic system could afford a general approach to enhance semiconductor-catalyzed photodegradation.

Improvement in Structure and Visible Light Catalytic Performance of g-C3N4 Fabricated at a Higher Temperature

A highly-efficient graphitic carbon nitride (g-C3N4) photocatalyst for visible light photodegradation of rhodamine B (RhB) and methyl orange (MO) simulating dyeing wastewater was synthesized by the thermal polycondensation of melamine. The photocatalysts were characterized by TG-DTG-DSC, XRD, EA, XPS, FT-IR, SEM, TEM, BET, PL and UV-vis DRS. The results showed that the photocatalytic performance of g-C3N4 at a higher calcination temperature was significantly enhanced, and its photocatalytic activities for the photodegradation of RhB and MO were remarkably improved by 64.91% and 41.83%, respectively, which was mainly attributed to the satisfactory crystallinity, stable graphene-like structure, large surface area, and excellent optical properties. It was found that •O2− radicals and •OH radicals were the main active species for the photodegradation process by the free radicals trapping experiments and ESR analysis. The photodegradation mechanism of g-C3N4 was proposed predicated using the characterization results.

A dual strategy for synthesizing crystal plane/defect co-modified BiOCl microsphere and photodegradation mechanism insights

Because of different atomic arrangements and/or different exposed atoms on different surfaces of crystalline particles, different physical and chemical properties can be resulted and exhibited. In this work, we prepared BiOCl with {110} crystal facet by introducing urea as the structure-directing agent, and constructed oxygen vacancies (OVs) in BiOCl (110) to form BiOCl (110)-OV. Control of exposure surface can improve photocatalyst activity and the defect level caused by OVs can improve charge separation and light absorption, thereby further enhancing the production of free radicals and the activation of pollutants. Due to the synergistic effect of the hierarchical microsphere structure of BiOCl and OVs, the degradation rate of tetracycline hydrochloride (20 mg/L) in the presence of BiOCl (110)-OV can reach 95.1% after 15 min of the simulated sunlight illumination. This research provides novel ideas for the design and development of photocatalyst with hierarchical structure and oxygen vacancy defects.

MIL-(53)Fe metal-organic framework (MOF)-based Ag2CrO4 hetrostructure with enhanced solar-light degradation of organic dyes

In this work, novel heterostructure photocatalyst contains MIL-53(Fe) and sliver chromate (Ag2CrO4) were successfully prepared through a precipitation method. The prepared composites included various weight percentages (25, 50, and 75%) of MIL-53(Fe). PXRD, FESEM, EDX, BET-BJH, UV–Vis, DRS, and FTIR techniques were used to study the structural, chemical, and optical properties of the prepared nanocomposites. Introducing Ag2CrO4 particles on the surface of MIL-53(Fe) with a high surface area led to the increase in the photocatalytic activity of Ag2CrO4 to remove AO7 dye under visible light irradiation. DRS analysis indicated that Ag2CrO4/MIL-53(Fe) has a narrower band-gap compared to MIL-53(Fe), and it can absorb light in the visible light region. The effect of photocatalyst dosage, initial solution pH, and initial dye concentration were investigated to evaluate the photocatalytic activity of prepared samples. The photo-degradation activity of AO7 dye was tremendously enhanced over Ag2CrO4/50%MIL-53(Fe) sample under the simulated solar light, and •OH and h+ were the main photodegradation mechanism. So, prepared Ag2CrO4/MIL-53(Fe) nanocomposites can be suggested as a potential and appropriate option to solve water pollution.

MOFs-derived Bi2O3@C with rich oxygen vacancies through rapid thermal annealing technology for photodegradation of tetracycline hydrochloride

Heavyuseof antibiotics keeping in the environment seriously threatens ecological security and human health. Photodegradation through Bi-based photocatalysts is regarded as an advanced green technology in solving environmental problems. Nevertheless, its photocatalytic activity is limited by the fast recombination of photogenerated e− and h+ pairs and the lower photo quantum efficiency. Herein, MOFs-derived Bi2O3@C with rich oxygen vacancies (OVs) has been designed and synthesized via infrared rapid thermal annealing technology, which increases the recrystallization temperature and reduces the grain size. The technology keeps the shape of the MOFs and maintains a large surface area with a high degree of dispersion of active components. The increased effective reactive sites and rich OVs of Bi2O3@C have great photoelectrochemical properties, high utilization of light energy and excellent electron transfer exhibiting efficient photodegradation for tetracycline hydrochloride (TCH). Therefore, the remove ratio of TCH reached 88% after irradiation of 5 W LED for 120 min. Moreover, the photodegradation mechanism is deeply explored through in-situ EPR and DRIFTS. 1O2 is the main reactive oxygen species to oxidize and mineralize the TCH. This MOFs-derived through rapid thermal annealing strategy would provide valuable insights to prepare inorganic nanomaterials with rich OVs for photocatalyst.

Spinel MgAl2O4 nanospheres coupled with modified graphitic carbon nitride nanosheets as an efficient Z-scheme photocatalyst for photodegradation of organic contaminants

In this contribution, spinel MgAl2O4 nanospheres prepared by the combustion method were coupled with thermally-exfoliated g-C3N4 nanosheets (TE-GCN) through an efficient isoelectric point-assisted calcination technique. Physical characteristics of the synthesized nanocomposite were understudied utilizing the XRD, FT-IR, FE-SEM, TEM, BET-BJH, UV–Vis DRS, PL, and EIS analyses. This material was used as a novel nano-photocatalyst for degradation of reactive red 195 (RR195) industrial dye contaminant. Results revealed that, a successful synthesis of a heterojunction between the components of the nanocomposite was achieved. This exhibited an enormously improved electron-hole separation leading to an enhanced decontamination of the RR195 compared with those of the individual components of the prepared photocatalyst. Next the investigation of the influential reaction parameters suggested that, a complete degradation of the aforementioned contaminant could have been achieved in a solution of pH of 3.0 containing a photocatalyst dosage of 0.9 g/L after 70 min of duration under simulated sunlight illumination. Ultimately, a Z-scheme charge transfer mechanism for photodegradation of the RR195 over the TE-GCN@MgAl2O4 photocatalyst was proposed. Notably, this photocatalyst was highly stable and only a negligible reduction of about 6% in the photodegradation efficiency of it occurred after 5 consecutive catalytic reaction cycles.

MFO@NZVI/hydrogel for sulfasalazine degradation: Performance, mechanism and degradation pathway

• MnFe 2 O 4 @NZVI/hydrogel was fabricated. • MnFe 2 O 4 @NZVI/hydrogel exhibited excellent photoactivation performance for sulfasalazine degradation. • The practical applicability of MnFe 2 O 4 @NZVI/hydrogel was investigated. • The reactive mechanism of MnFe 2 O 4 @NZVI/hydrogel photodegradation was proposed. The fabrication of heterogeneous photocatalyst with superior redox capability has been emerged as a prospective strategy for wastewater remediation. In this study, we optimized the conformation of MFO@NZVI/hydrogel photocatalyst, which exhibited superior photocatalytic activity towards sulfasalazine (SFZ), up to 77.88% within 180 min. The effect of diversified influencing parameters on the photodegradation efficiency was systematically investigated. Besides, we conducted XRD, SEM, FT-IR and UV–vis DRS to investigate the structure, morphology and optical properties of MFO@NZVI/hydrogel, respectively. Meanwhile, we tested that the band gaps of photocatalyst were as follow: pure hydrogel (4.51 eV) > MFO@NZVI (3.29 eV) > MFO (2.74 eV) > MFO@NZVI/hydrogel (2.45 eV) > NZVI (1.59 eV). Hence, we suggested that MFO@NZVI/hydrogel could rapidly capture and transport electrons for effective charge separation, promoting the generation of reaction oxygen species (∙O 2 – , ∙OH, h + and 1 O 2 ) for photocatalytic. Furthermore, a possible mechanism and intermediates for SFZ photodegradation has been elucidated. Moreover, the photodegradation efficiency of MFO@NZVI/hydrogel was 77.68% for SFZ after 9 cycles, contributing to its excellent recovery and stability. Therefore, we demonstrated the feasibility of MFO@NZVI/hydrogel photocatalytic system and provided insight on the design of high-performance photocatalyst for removal process of persistent pollutants.

Synthesis of hierarchical Cu2CdSnS4 by microwave-assisted transformation from precursor for photodegradation to malachite green

In this paper, 500–600 nm hierarchical flower-like Cu2CdSnS4 (CCTS) was synthesized by two-step method, which was applied in the photodegradation to malachite green (MG) for the first time. With spherical CdSn(OH)6 prepared by co-precipitation method as the precursor, flower-like CCTS micro/nano structured crystals were synthesized by microwave method. The formation of CCTS experienced CdSn(OH)6 coordinating with sulfur source, then dissolving partly to combine with Cu2+ in the existence of PVP as the capping agent, finally to form flower-like structure. The characterization of products showed that stannite CCTS had narrow bandgap and large special interface area, contributing to excellent photodegradation to MG up to 90.29%. The decomposition of MG may originate from N-demethylation, removal of the benzene ring and ring-open reactions. The deep understanding of the photodegradation mechanism may provide the guidance in the long-term study of MG.

Near UV and Visible Light Photo-Degradation Mechanisms in Citrate Buffer: One-Electron Reduction of Peptide and Protein Disulfides promotes Oxidation and Cis/Trans Isomerization of Unsaturated Fatty Acids of Polysorbate 80

Citrate is a common buffer for slightly acidic pH ranges of protein formulations. In the presence of iron, citrate buffer undergoes photo-degradation induced by near UV and visible light. Recent studies (Subelzu and Schöneich, Mol. Pharm. 2020, 17, 4163-4179) have documented that such photo-degradation results in the formation of carbon dioxide radical anion (•CO2−), a strong reductant which reduces Fe3+, O2, and disulfide bonds. In the present study we show that near UV and visible light photo-degradation of citrate in the presence of iron can induce reductive peptide and protein disulfide cleavage as well as free radical damage of a surfactant, polysorbate 80 (PS80). Reductive disulfide cleavage is most likely caused by efficient electron transfer from carbon dioxide radical anions to disulfides, resulting in the generation of thiol/thiolate and thiyl radicals. The latter can react with mono- and polyunsaturated fatty acids of PS80 to cause cis/trans isomerization and/or oxidation. Representative products generated by cis/trans isomerization and oxidation of oleic acid esters have been detected by HPLC-MS analysis. Further evidence for reductive disulfide cleavage was obtained through the analysis of free thiols. The oxidation of PS80 can also be the consequence of reactive oxygen species (ROS) generation through the reduction of O2 by carbon dioxide radical anions and/or intermediary Fe2+.

Photocatalytic Degradation of Fluoroquinolone Antibiotics in Solution by Au@ZnO-rGO-gC3N4 Composites

The photocatalytic degradation of two quinolone-type antibiotics (ciprofloxacin and levofloxacin) in aqueous solution was studied, using catalysts based on ZnO nanoparticles, which were synthesized by a thermal procedure. The efficiency of ZnO was subsequently optimized by incorporating different co-catalysts of gC3N4, reduced graphene oxide, and nanoparticles of gold. The catalysts were fully characterized by electron microscopy (TEM and SEM), XPS, XRD, Raman, and BET surface area. The most efficient catalyst was 10%Au@ZnONPs-3%rGO-3%gC3N4, obtaining degradations of both pollutants above 96%. This catalyst has the largest specific area, and its activity was related to a synergistic effect, involving factors such as the surface of the material and the ability to absorb radiation in the visible region, mainly produced by the incorporation of rGO and gC3N4 in the semiconductor. The use of different scavengers during the catalytic process, was used to establish the possible photodegradation mechanism of both antibiotics.

The visible light photocatalytic degradation of ethylene using a polyvinyl alcohol film loaded with Ag2O-TiO2-Bi2WO6 heterojunction microspheres

In this study, Ag2O-TiO2-Bi2WO6(ATB) heterojunction microsphere photocatalyst was synthesized by hydrothermal and surface deposition method. ATB was loaded onto the surface and interior of polyvinyl alcohol (PVA) films to construct a novel ATB/PVA composite film with photocatalytic degradation performance of ethylene by internal doping and surface loading method. The ATB microspheres and ATB/PVA composite films were characterized, and the photodegradation effect and mechanism of ethylene by ATB/PVA composite films was investigated. The results showed that ATB had the best ethylene degradation effect, and the reaction rate constant K' value was 6.0722 × 10-4 min−1, which was 11.79, 2.71 and 1.48 times than that of TiO2, Bi2WO6 and TiO2/Bi2WO6(TB), respectively. The improvement of photocatalytic activity was mainly attributed to the addition of Ag2O, which enhanced the visible light absorption performance and reduced the band gap of ATB. The formation of ternary heterostructures promoted the separation and transfer efficiency of photogenerated carriers. When the internal doping amount of ATB was 3 wt% and the surface loading amount was 1.5 wt%, the ATB microspheres were well dispersed inside and on the surface of PVA film, and the ATB/PVA composite film had the best ethylene degradation performance with K 'value of 6.8107 × 10-4 min−1, which was increased by 12.16% compared with the pure internal doping film.

Synergistic effect of single-atom Ag and hierarchical tremella-like g-C3N4: Electronic structure regulation and multi-channel carriers transport for boosting photocatalytic performance

It is significant to realize the synergistic effect of single-atom sites and its support to obtain excellent performance photocatalysts. Here, single-atom silver (SAAg) is embedded into the hierarchical tremella-like carbon nitride (3DT-CN) by an efficient one-step reduction method. The photo-degradation mechanism of SAAg/3DT-CN for tetracycline (TC) is first proposed. And the synergistic effect to improve photocatalytic activity is also discussed in depth. Density functional theory (DFT) calculations and physicochemical characterizations reveal that the synergistic effect of SAAg and 3DT-CN has improved the absorption capacity of visible light, the binding energy with oxygen, charge transfer behavior and other properties. Electron spin resonance (ESR) and capture experiments validate the active species involved in the reaction. The first-order kinetic constant of TC degradation by SAAg/3DT-CN is 8.4 times and 3.8 times that of 3DT-CN and AgNP/3DT-CN in 75 min, respectively. This work provides a meritorious structure-activity strategy for the removal of refractory antibiotics.

Review on Methylene Blue: Its Properties, Uses, Toxicity and Photodegradation

The unavailability of clean drinking water is one of the significant health issues in modern times. Industrial dyes are one of the dominant chemicals that make water unfit for drinking. Among these dyes, methylene blue (MB) is toxic, carcinogenic, and non-biodegradable and can cause a severe threat to human health and environmental safety. It is usually released in natural water sources, which becomes a health threat to human beings and living organisms. Hence, there is a need to develop an environmentally friendly, efficient technology for removing MB from wastewater. Photodegradation is an advanced oxidation process widely used for MB removal. It has the advantages of complete mineralization of dye into simple and nontoxic species with the potential to decrease the processing cost. This review provides a tutorial basis for the readers working in the dye degradation research area. We not only covered the basic principles of the process but also provided a wide range of previously published work on advanced photocatalytic systems (single-component and multi-component photocatalysts). Our study has focused on critical parameters that can affect the photodegradation rate of MB, such as photocatalyst type and loading, irradiation reaction time, pH of reaction media, initial concentration of dye, radical scavengers and oxidising agents. The photodegradation mechanism, reaction pathways, intermediate products, and final products of MB are also summarized. An overview of the future perspectives to utilize MB at an industrial scale is also provided. This paper identifies strategies for the development of effective MB photodegradation systems.

Promising solar photodegradation of RY 86 by hydrophilic F127 (pluronic) aided nano cobalt ferrite and its biomedical applications

To our surprise, we effectively excelled in developing the hydrophilic, non-ionic and water soluble triblock copolymer surfactant F127 (pluronic) aided spinel cobalt ferrite (CFO) nanoparticles. The crystalline nature and surface morphology of F127 aided CFO nanoparticles have been confirmed laboriously by XRD, HR-TEM, DLS, FT-RAMAN, FT-IR, UV-DRS, and SEM-EDX. SEM confirms undeclared rod-like structure and HR-TEM supports a shape similar to quasi-spherical morphology. The band gap investigation report that the Eg value of F127 aided CFO is around 1.24 eV. We found the fact that, in the UV/solar light degradation of hazardous Reactive Yellow 86 (RY 86), the photocatalytic activity of F127 aided CFO nanoparticles was accelerated by the presence of H2O2. F127 is a surfactant that played a key role in the enhanced activity of F127 aided CFO nanoparticles. By using an external magnetic field, the catalyst can be recovered from the fluid medium and thereby reused. The feasible mechanism for active liquid phase photodegradation of RY 86 has also been developed. Therefore, we assure that the novel spinel F127 aided CFO nanoparticles will shed more light for the wastewater treatment system because of its effective photocatalytic and reusable behavior. In conjunction, the antibacterial function and cytotoxicity are also performed.

Facile Preparation and Controllable Absorption of a Composite Based on PMo12/Ag Nanoparticles: Photodegradation Activity and Mechanism”

AbstractTo overcome the low photocatalytic activity and efficiently harvest solar energy, a new type of composite photocatalyst PMo12/AgNPs is constructed based on polymolybdate (PMo12) and Ag nanosheets as the co‐active ingredient, and the composite material is characterized by FT‐IR, XRD, EDS, SEM, UV‐vis, EIS and PL. In this study, the controllable absorption range silver nanosheets with different sizes and morphologies are prepared by regulating the reaction condition, and the nanosheets further combined with PMo12 polyoxoanion to construct composite photocatalyst with efficient visible‐light response and photocatalytic activity. The EIS plots, Bode plots and PL spectra analysis results indicate that the PMo12/28 h‐AgNPs hybrid material exhibits excellent interfacial charge transfer efficiency and potential photocatalytic application. The photodegradation experiment of rhodamine B (RhB) is selected as the model reaction to evaluate the catalytic activity of PMo12/28 h‐AgNPs hybrid material under simulate visible light, in which the photocatalytic degradation98.75 % with pH=5 for PMo12/28 h‐AgNPs is higher than that of others. The .O2− and h+ are detected as active groups by different scavengers tests, and the possible photocatalytic mechanism of the composites is investigated.

Investigation of heterojunction between α-Fe2O3/V2O5 and g-C3N4 ternary nanocomposites for upgraded photo-degradation performance of mixed pollutants: Efficient dual Z-scheme mechanism

In this present work, a g-C3N4 decorated dual Z-scheme α-Fe2O3 and V2O5 heterojunction of magnetically recoverable GFV (g-C3N4/α-Fe2O3/V2O5) composite was rationally synthesized using facile calcination and hydrothermal approach. The crystal structure, surface morphology, chemical composition and optical properties of the as-obtained composite photocatalysts (PCs) were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra high-resolution scanning electron microscopy (HR-SEM, high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS) measurement, UV-Vis diffuse reflectance spectra (DRS) and photoluminescence (PL) analyses respectively. Benefiting from these structural and compositional features, the optimum GFV heterostructured PCs sample revealed that the superior photo-degradation performance of methyl yellow (MY) and methylene blue (MB) mixed dye under visible-light, while the degradation rates were 93.4% for MY and 87.5% for MB dye at 90 min, respectively. Moreover, the enhanced photo-degradation performance of GFV composite PCs displayed an extended visible-light fascination due to lower bandgap, reduced recombination rates, high charge separation and good charge transfer capacity with the efficient dual Z-scheme heterojunction. Meanwhile, high photo-degradation stability is continued after five successive reusability tests. A possible photo-degradation mechanism of dual Z-scheme charge transfer paths was also been proposed. This study is also capable of emerging visible-light active facile heterojunction photocatalysts for various organic pollutants removal with great efficiency.