Highly Efficient Visible Light Active 2D-2D Nanocomposites of N-ZnO-g-C3 N4 for Photocatalytic Degradation of Diverse Industrial Pollutants

CeO2 nanospheres incorporated with Bi2MoO6/g-C3N4 enhanced photocatalysis towards environmental pollutant Rhodamine B removal

We have adopted a novel CeO2/Bi2MoO6/g-C3N4-based ternary nanocomposite that was synthesized via hydrothermal technique. The physiochemical characterization of as-prepared samples was examined through various analytical techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy TEM, photoluminescent spectra (PL), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and ultraviolet diffuse reflectance spectroscopy (UV-DRS) technique. In addition, the photocatalytic performance was carried out by degradation of Rhodamine B dye under visible light irradiation using this nanocatalyst. The ternary nanocomposite achieved 94% of the degradation efficiency within 100 min which is higher than the pristine and binary composites under the predetermined condition pH = 7, Rhodamine B dye = 5 mg/L, and catalyst concentration = 150 mg/L. The experimental synergetic effect of CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite has been ascribed to the interfacial charge carrier migration between CeO2, Bi2MoO6, and g-C3N4. The optical absorption range of CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite was enhanced, and the band gap was reduced up to 2.2 eV. In addition, scavenger trapping experiment proves that the super oxide anions (O2-.) and photogenerated holes are the major active species. The reusability and stability experiment proved the CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite keeps good durability during the photocatalytic degradation process after the five successive cycles. Furthermore, based on the results, the charge carrier transfer photocatalytic mechanism was also discussed. This CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite may offer the cheapest material and extend the great opportunity for clean and environmental remediation approach under the visible light irradiation.

Highly efficient visible-light induced N-doped ZnO@g-C3N4 and S-doped ZnO@g-C3N4 photocatalysts for environmental remediation

Facile, cost-effective and eco-friendly synthesis of N-doped ZnO@g-C3N4 and S-doped ZnO@g-C3N4 photocatalysts towards efficient degradation of environmental pollutants was achieved. The as-synthesized 2 wt% N-doped ZnO@g-C3N4 and 2 wt% S-doped ZnO@g-C3N4 achieved 96.2% and 90.4% degradation efficiencies towards crystal violet (100 ppm) within 45 min irradiation and 99.3% and 92.3% photocatalytic degradation efficiencies towards brilliant green (100 ppm) dye within 30 min irradiation, respectively, under a normal 90 W LED light instead of an expensive commercial light source. Moreover, the N-doped ZnO@g-C3N4 and S-doped ZnO@g-C3N4 nanocomposites showed excellent stability in the photodegradation of crystal violet and brilliant green dyes. The modification made on ZnO by doping with nitrogen and sulphur enhances the visible-light absorption as well as the separation of photoexcited charge carriers. The active radicals ˙OH and ˙O2- are both identified to play important roles in the photodegradation of crystal violet and brilliant green.

NaBiS2 decorated polysaccharide sponges for adsorption-photocatalytic degradation of dye under visible light illumination

Dye is emissions aggravating aquatic ecosystem pollution, and photocatalysis is considered the most appealing option to remove dyes by degradation. However, the current photocatalysts suffer from agglomeration, large bandgaps, high mass transfer resistance, and high operation cost. Herein, we present a facile hydrothermally induced phase separation and in situ synthesis strategy for fabrication of sodium bismuth sulfide (NaBiS₂)-decorated chitosan/cellulose sponges (NaBiCCSs). The NaBiCCSs demonstrate unique polysaccharide cellular structure (150-500 μm), uniformly immobilized NaBiS₂ nanoparticles (70-90 nm), narrow bandgap (1.18 eV), high photocurrent (0.74 μA/cm²), and outstanding compressibility. Benefiting from the characteristics and the high affinity to dyes, the NaBiCCSs provide innovative synergistic adsorption-photocatalytic degradation model for dye removal, attaining a superior methylene blue removal rate of 98.38 % under visible light illumination and offering good reusability. This study offers a sustainable technical solution for dye contaminant removal.

Adsorptive-Photocatalytic Performance for Antibiotic and Personal Care Product Using Cu0.5Mn0.5Fe2O4

The amount of antibiotics and personal care products entering local sewage systems and ultimately natural waters is increasing and raising concerns about long-term human health effects. We developed an adsorptive photocatalyst, Cu_0.5Mn_0.5Fe₂O₄ nanoparticles, utilizing co-precipitation and calcination with melamine, and quantified its efficacy in removing paraben and oxytetracycline (OTC). During melamine calcination, Cu_0.5Mn_0.5Fe₂O₄ recrystallized, improving material crystallinity and purity for the adsorptive-photocatalytic reaction. Kinetic experiments showed that all four parabens and OTC were removed within 120 and 45 min. We found that contaminant adsorption and reaction with active radicals occurred almost simultaneously with the photocatalyst. OTC adsorption could be adequately described by the Brouers-Sotolongo kinetic and Freundlich isotherm models. OTC photocatalytic degradation started with a series of reactions at different carbon locations (i.e., decarboxamidation, deamination, dehydroxylation, demethylation, and tautomerization). Further toxicity testing showed that Zea mays L. and Vigna radiata L. shoot indexes were less affected by treated water than root indexes. The Zea mays L. endodermis thickness and area decreased considerably after exposure to the 25% (v/v)-treated water. Overall, Cu_0.5Mn_0.5Fe₂O₄ nanoparticles exhibit a remarkable adsorptive-photocatalytic performance for the degradation of tested antibiotics and personal care products.

Solar light driven enhanced photocatalytic treatment of azo dye contaminated water based on Co-doped ZnO/ g-C3N4 nanocomposite

The current research concentrated on the Co-precipitation synthesis of g-C₃N₄ (CN), ZnO, ZnO/CN, and Co-doped ZnO/CN nanocomposite, as well as the solar light enhanced photocatalytic treatment of Reactive Red 120 (RR120) from genuine wool textile effluent. The 3D flower-like structure of Co-doped ZnO distributed on the surface of CN thin sheets, according to structural studies employing XRD and SEM examinations Electrochemical experiments exhibited that the Co-doped ZnO/CN nanocomposite has a large electroactive surface area. The optical band-gap values of CN, ZnO, ZnO/CN, and Co-doped ZnO/CN nanocomposites were 2.68, 3.13, 2.38, and 2.23 eV, respectively, according to optical characterizations. The synergistic effects and heterojunction produced by Co-doped ZnO and CN can be linked to the narrow gap in nanocomposites. After 75, 60, 50, and 40 min of exposure to solar light, photocatalytic degradation assays for 250 mL of 20 mg/L RR120 solution in the presence of CN, ZnO, ZnO/CN, and Co-doped ZnO/CN nanocomposites demonstrated 100% dye treatment. The applicability of photocatalysts for decolorization of 250 mL of 10 mg/L RR120 prepared from actual wool textile wastewater was investigated, and the results showed that Co-doped ZnO/CN nanocomposites for treatment of RR120 from actual wool textile wastewater were highly efficient at photocatalytic degradation.

Critical parameters influencing the continuous performance of upflow microbubble airlift photocatalytic process treating pharmaceutical pollutants

The advances in heterogeneous photocatalysts are still confined to evaluating the functional photocatalytic activity of catalysts in simple batch-mode operation. Nevertheless, the long-term stability, recovery-reusability, and cost-effectiveness of photocatalysts are critical issues in practical applications for pollution control. This study examined the critical parameters to improve the photocatalytic degradation activity of the antibiotic tetracycline and strategized successful continuous performance in a two-stage photocatalytic process adopting sequencing batch-mode microbubble upflow airlift reactor (UALR) followed by the centrifugal separation of CdS nanoparticles (NPs). The most effective strategy for NPs separation was a sequential combination of gravity separation (10 min settling) in the settling phase and subsequent high-speed centrifugation (5 min at 25,000×g) of the settled NPs sediments, providing an economic benefit by reducing the centrifugation capacity. During steady state operation under the optimal conditions, the UALR showed reliable performance, resulting in 97-91% and 85-81% degradation efficiency at 60- and 30-min reaction time per cycle, respectively. A weak basic condition (pH 8) and dissolved oxygen (DO) supplementation increased the photocatalytic activity by 12% (0.0292 min^-1) and 30% (0.0363 min^-1) compared to the control. Trapping studies confirmed the enhanced performance using various reactive oxygen species scavengers, revealing an increase in ^•OH generation (6.5%).

Preparation of carnation-like Ag-ZnO composites for enhanced photocatalysis under visible light

Carnation-like ZnO was synthesized by the facile precipitation method (at room temperature and in 120 min) to decompose dyes in an aqueous medium. The carnation-like ZnO had a stratified porous structure with a size of about 2-3μm, its petals had a smooth surface with a thickness of 5-10 nm and a width of about 300-500 nm. Ag-ZnO composites were synthesized using glucose with the assistance of PVP. The morphology of Ag-ZnO composites was almost unchanged compared to ZnO. Where, the Ag nanoparticles in the size range of 5-15 nm were uniformly dispersed on the ZnO petals, improving the catalytic ability of the composites in tartrazine (TA) degradation. The influence of Ag content on catalytic structure and performance of composite was studied. The 5Ag-ZnO sample had the highest BET surface area and pore volume and the lowest gap energy (Eg) among the as-synthesized samples. The 5Ag-ZnO sample proclaimed the degradation efficiency in 70 min of 97.8% and thek_apof 0.031 min^-1. The influences of catalyst content, solution pH, and concentration of dye on the photodegradation efficiency of the composite were thoroughly studied. Besides, the photocatalytic activity of the composite was demonstrated by degrading various organic substances and reusability. In addition, it was compared to a metal-semiconductor catalyst of Au-ZnO and semiconductor-semiconductor catalysts of MoS₂-ZnO, Cu₂O-ZnO, and SiO₂-ZnO. The catalytic mechanism under visible light was proposed.

Electron flux at the Schottky junction of Bi NPs and WO3-supported g-C3N4: an efficient ternary S-scheme catalyst for removal of fluoroquinolone-type antibiotics from water

Recently, global-scale attempts have been conducted to develop clean technologies and affordable materials to remediate pharmaceutical contaminants of water resources that are resistant to the biodegradation. In line with global efforts, this study reports a facile method to fabricate Bi nanocrystals in situ decorated on WO₃ nanoplates and its composite with graphitic carbon nitride (WO₃/Bi/g-C₃N₄) for photocatalytic degradation of fluoroquinolone-type antibiotics (ciprofloxacin and ofloxacin). The designed ternary S-scheme WO₃/Bi/g-C₃N₄ composite material was fully characterized by physicochemical and electrochemical analysis. Depositing the cost-effective and earth-abundant Bi nanocrystals onto WO₃ via a facile reduction route has been shown to increase the boosting of electron flux at their interface (Schottky junction). The S-scheme separation is confirmed by the calculation of band positions and the analysis of photogenerated hydroxyl radicals and holes. The complete removal of contaminants was obtained over the WO₃/Bi/g-C₃N₄ photocatalyst after 90 min under visible light irradiation. The present work would provide a rational route for developing Bi NP-based photocatalysis to replace metallic Au, Pt, and Ag NPs.

MXene coupled graphitic carbon nitride nanosheets based plasmonic photocatalysts for removal of pharmaceutical pollutant

The continuous rise in the amount of industrial and pharmaceutical waste in water sources is an alarming concern. Effective strategies should be developed for the treatment of pharmaceutical industrial waste. Hence the alternative renewable source of energy, such as solar energy, should be utilized for a sustainable future. Herein, a series of Au plasmonic nanoparticle decorated ternary photocatalysts comprising graphitic carbon nitride and Ti₃C₂ MXene has been designed to degrade colourless pharmaceutical pollutants, cefixime under visible light irradiation. These photocatalysts were synthesized by varying the amount of Ti₃C₂ MXene, and their catalytic potential was explored. The optimized photocatalyst having 3 wt% Ti₃C₂ MXene achieved 64.69% removal of the pharmaceutical pollutant, cefixime within 105 min of exposure to visible light. The presence of the Au nanoparticles and MXene in the nanocomposite facilitates the excellent charge carrier separation and increased the number of active sites due to the formation of interfacial contact with graphitic carbon nitride nanosheets. Besides, the plasmonic effect of the Au nanoparticles improves the absorption of light causing enhanced photocatalytic performance of the nanocomposite. Based on the obtained results, a plausible mechanism has been formulated to understand the contribution of different components in photocatalytic activity. In addition, the optimized photocatalyst shows excellent activity and can be reused for up to three cycles without any significant loss in its photocatalytic performance. Overall, the current work provides deeper physical insight into the future development of MXene graphitic carbon nitride-based plasmonic ternary photocatalysts.

Construction of Highly Active Zn3In2S6 (110)/g-C3N4 System by Low Temperature Solvothermal for Efficient Degradation of Tetracycline under Visible Light

Herein, Zn3In2S6 photocatalyst with (110) exposed facet was prepared by low temperature solvothermal method. On this basis, a highly efficient binary Zn3In2S6/g-C3N4 was obtained by low temperature solvothermal method and applied to the degradation of tetracycline (TC). The samples of the preparation were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, UV–vis diffuse reflection spectroscopy, and photoluminescence spectroscopy. Furthermore, the degradation performance of photocatalysts on TC was investigated under different experimental conditions. Finally, the mechanism of Zn3In2S6/g-C3N4 composite material degrading TC is discussed. The results show that Zn3In2S6 and Zn3In2S6/g-C3N4 photocatalysts with excellent performance could be successfully prepared at lower temperature. The Zn3In2S6/g-C3N4 heterojunction photocatalyst could significantly improve the photocatalytic activity compared with g-C3N4. After 150 min of illumination, the efficiency of 80%Zn3In2S6/g-C3N4 to degrade TC was 1.35 times that of g-C3N4. The improvement of photocatalytic activity was due to the formation of Zn3In2S6/g-C3N4 heterojunction, which promoted the transfer of photogenerated electron–holes. The cycle experiment test confirmed that Zn3In2S6/g-C3N4 composite material had excellent stability. The free radical capture experiment showed that ·O2− was the primary active material. This study provides a new strategy for the preparation of photocatalysts with excellent performance at low temperature.

Fabrication of Cr-ZnFe2O4/S-g-C3N4 Heterojunction Enriched Charge Separation for Sunlight Responsive Photocatalytic Performance and Antibacterial Study

There has been a lot of interest in the manufacture of stable, high-efficiency photocatalysts. In this study, initially Cr doped ZnFe₂O₄ nanoparticles (NPs) were made via surfactant-assisted hydrothermal technique. Then Cr-ZnFe₂O₄ NPs were modified by incorporating S-g-C₃N₄ to enhance their photocatalytic efficiency. The morphological, structural, and bonding aspects were analyzed by XRD, FTIR, and SEM techniques. The photocatalytic efficiency of the functional Cr-ZnFe₂O₄/S-g-C₃N₄ (ZFG) heterostructure photocatalysts was examined against MB under sunlight. The produced ZFG-50 composite has the best photocatalytic performance, which is 2.4 and 3.5 times better than that of ZnFe₂O₄ and S-g-C₃N₄, respectively. Experiments revealed that the enhanced photocatalytic activity of the ZFG nanocomposite was caused by a more effective transfer and separation of photo-induced charges. The ZFG photocatalyst can use sunlight for treating polluted water, and the proposed modification of ZnFe₂O₄ using Cr and S-g-C₃N₄ is efficient, affordable, and environmentally benign. Under visible light, Gram-positive and Gram-negative bacteria were employed to ZFG-50 NCs’ antimicrobial activity. These ZFG-50 NCs also exhibit excellent antibacterial potential.

Constructing novel graphitic carbon nitride-based nanocomposites - From the perspective of material dimensions and interfacial characteristics

Two-dimensional (2D) graphitic carbon nitride (g-C₃N₄), a fascinating metal-free conjugated polymer, has garnered immense interest in the fields of solar power generation and environmental remediation. The construction of g-C₃N₄-based nanocomposites with materials of various dimensions can further improve their photocatalytic activities by surface area enlargement, bandgap tuning, heterojunction formation, etc. In this paper, we comprehensively reviewed the design, synthesis, and functionalities of g-C₃N₄-based nanocomposites based on their applications in hydrogen evolution, CO₂ reduction, and pollutants removal. We provided detailed analyses on the integration of 2D g-C₃N₄ with zero-, one-, two-, and three-dimensional materials with a focus on their interfacial characteristics and functional improvement. This review aims to stimulate fresh ideas on the interfacial engineering of g-C₃N₄-based nanocomposites to broaden their future applications.

Nanocomposite ZnO/g-C3N4 for Improved Degradation of Dyes under Visible Light: Facile Preparation, Characterization, and Performance Investigations

In this study, ZnO/g-C3N4 nanocomposites were prepared via a physical mixing-calcination process for improved degradation of dyes under visible light irradiation. The BET surface area, pore volume, crystal size, and pHpzc of the ZnO/g-C3N4 composite were 3.9 m2/g, 0.034 cm3/g, 18.1 nm, and 7.7, respectively. Although the morphology of the ZnO/g-C3N4 composite was very different from that of pure g-C3N4, their average pore sizes were similar. The Eg of the ZnO/g-C3N4 composite (3.195 eV) was slightly lower than that of ZnO (3.195) but much higher than that of g-C3N4 (2.875). The interface interaction of ZnO and g-C3N4, which was revealed by oscillations of Zn-C, benefited the transport of photoinduced charge carriers and reduced the recombination of electron-hole. As the result, the ZnO/g-C3N4 composite had higher photocatalytic activity than ZnO and g-C3N4. Its degradation efficiency (DE) value for methylene blue (MB) in 90 min and rate constant were 93.2 % and 0.025 min‑1, respectively. In addition, the effects of ZnO/urea molar ratio, catalyst dosage, solution pH, and concentration of dye on photocatalytic degradation of MB were completely investigated. The photocatalytic performance of the ZnO/g-C3N4 composite was evaluated by the degradation of other persistent organic compounds, also compared to other catalysts in the literatures. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Recent advances and challenges in 2D/2D heterojunction photocatalysts for solar fuels applications

Although photocatalytic technology has emerged as an effective means of alleviating the projected future fuel crisis by converting sunlight directly into chemical energy, no visible-light-driven, low-cost, and highly stable photocatalyst has been developed to date. Due to considerably higher interfacial contact with numerous reactive sites, effective charge transmission and separation ability, and strong redox potentials, the focus has now shifted to 2D/2D heterojunction systems, which have exhibited effective photocatalytic performance. The fundamentals of 2D/2D photocatalysis for different applications and the classification of 2D/2D materials are first explained in this paper, followed by strategies to improve the photocatalytic performance of various 2D/2D heterojunction systems. Following that, current breakthroughs in 2D/2D metal-based and metal-free heterojunction photocatalysts, as well as their applications for H₂ evolution via water splitting, CO₂ reduction, and N₂ fixation, are discussed. Finally, a brief overview of current constraints and predicted results for 2D/2D heterojunction systems is also presented. This paper lays out a strategy for developing efficient 2D/2D heterojunction photocatalysts and sophisticated technology for solar fuel applications in order to address the energy issue.

A Comprehensive Review of Graphitic Carbon Nitride (g-C3N4)-Metal Oxide-Based Nanocomposites: Potential for Photocatalysis and Sensing

g-C3N4 has drawn lots of attention due to its photocatalytic activity, low-cost and facile synthesis, and interesting layered structure. However, to improve some of the properties of g-C3N4, such as photochemical stability, electrical band structure, and to decrease charge recombination rate, and towards effective light-harvesting, g-C3N4-metal oxide-based heterojunctions have been introduced. In this review, we initially discussed the preparation, modification, and physical properties of the g-C3N4 and then, we discussed the combination of g-C3N4 with various metal oxides such as TiO2, ZnO, FeO, Fe2O3, Fe3O4, WO3, SnO, SnO2, etc. We summarized some of their characteristic properties of these heterojunctions, their optical features, photocatalytic performance, and electrical band edge positions. This review covers recent advances, including applications in water splitting, CO2 reduction, and photodegradation of organic pollutants, sensors, bacterial disinfection, and supercapacitors. We show that metal oxides can improve the efficiency of the bare g-C3N4 to make the composites suitable for a wide range of applications. Finally, this review provides some perspectives, limitations, and challenges in investigation of g-C3N4-metal-oxide-based heterojunctions.

2D/2D Heterojunction systems for the removal of organic pollutants: A review

Photocatalysis is considered to be an effective way to remove organic pollutants, but the key to photocatalysis is finding a high-efficiency and stable photocatalyst. 2D materials-based heterojunction has aroused widespread concerns in photocatalysis because of its merits in more active sites, adjustable band gaps and shorter charge transfer distance. Among various 2D heterojunction systems, 2D/2D heterojunction with a face-to-face contact interface is regarded as a highly promising photocatalyst. Due to the strong coupling interface in 2D/2D heterojunction, the separation and migration of photoexcited electron-hole pairs are facilitated, which enhances the photocatalytic performance. Thus, the design of 2D/2D heterojunction can become a potential model for expanding the application of photocatalysis in the removal of organic pollutants. Herein, in this review, we first summarize the fundamental principles, classification, and strategies for elevating photocatalytic performance. Then, the synthesis and application of the 2D/2D heterojunction system for the removal of organic pollutants are discussed. Finally, the challenges and perspectives in 2D/2D heterojunction photocatalysts and their application for removing organic pollutants are presented.

Novel VUV/g-C3N4 system with high adaptability to varied environmental conditions and outstanding degradation capacity for chlorophenols

Given the limitations of conventional vacuum ultraviolet (VUV) systems, a novel vacuum ultraviolet/graphite carbon nitride (VUV/g-C₃N₄) system with high adaptability to varying environmental conditions was developed. Compared with conventional VUV and UV/g-C₃N₄ systems, the VUV/g-C₃N₄ system demonstrates a much higher ability for the efficient degradation of chlorophenols (CPs). In particular, the VUV/g-C₃N₄ system exhibits outstanding performance even at low pH and high concentrations of humic acid and SO₄^2-. Alkaline conditions and the presence of HCO₃^- can further promote CP removal. In addition, the feasibility of the VUV/g-C₃N₄ system was verified by its stable operation in both river water and tap water. Unlike conventional photochemical systems relying on •OH, the dominant reactive species for CP degradation by the VUV/g-C₃N₄ system was identified to be •O₂^-. This study conclusively provided a novel system for the efficient photocatalytic treatment of pollutants.

Anionic polyacrylamide-assisted construction of thin 2D-2D WO3/g-C3N4 Step-scheme heterojunction for enhanced tetracycline degradation under visible light irradiation

Thin 2D/2D WO₃/g-C₃N₄ Step-scheme (S-scheme) heterojunction with carbon doping and bridge (C-W/N) was constructed with anionic polyacrylamide (APAM), in which APAM functioned as an assistant templet and a carbon source. APAM and WO₃ were inserted into g-C₃N₄ nanosheet. The carbon, thin planar structure and WO₃ with oxygen vacancies result in fast charge transfer, high quantum efficiency and strong driving force for photocatalytic reaction. Consequently, as-prepared C-W/N ternary composite photocatalyst exhibited significantly enhanced photocatalytic performance for tetracycline (TC) degradation under visible light compared to pure g-C₃N₄, WO₃ and other binary composites. Moreover, the material showed high stability and reusability in cyclic TC degradation. The principal intermediate products over C-W/N photocatalyst were revealed by HPLC-MS analysis. Corresponding degradation pathway of TC was also presented in this work. According to the trapping experiments, analysis of electron spin resource (ESR) and band gap, possible charge transfer pathways of C-W/N are proposed and discussed in detail. Based on the results, carbon derived from APAM works not only as electron mediator but also as acceptor for photocatalytic degradation reaction. It is a promising way to further modulate heterojunction for varies applications.

Facile fabrication of porous BiVO4hollow spheres with improved visible-light photocatalytic properties

Bismuth vanadate (BiVO₄) hollow spheres with porous structure have been successfully fabricated by a one-step wet solution method with no surfactant and template.

Fabrication of corncob-derived biomass charcoal decorated g-C3N4photocatalysts for removing 2-mercaptobenzothiazole

Insights into active sites and charge transport behavior are challenging topics for fabricating composite photocatalysts and investigating their photocatalytic degradation reaction mechanisms.

A heterojunction photocatalyst constructed by the modification of 2D-CeO2 on 2D-MoS2 nanosheets with enhanced degrading activity

A new 2D/2D heterojunction of MoS₂/CeO₂ is successfully prepared by a facile hydrothermal method.

Graphene-based plasmonic nanocomposites for highly enhanced solar-driven photocatalytic activities

High-efficiency photocatalysts are crucial for the removal of organic pollutants and environmental sustainability. In the present work, we report on a new low-temperature hydrothermal chemical method, assisted by ultrasonication, to synthesize disruptive plasmonic ZnO/graphene/Ag/AgI nanocomposites for solar-driven photocatalysis. The plasmonic nanocomposites were investigated by a wide range of characterization techniques, confirming successful formation of photocatalysts with excellent degradation efficiency. Using Congo red as a model dye molecule, our experimental results demonstrated a photocatalytic reactivity exceeding 90% efficiency after one hour simulated solar irradiation. The significantly enhanced degradation efficiency is attributed to improved electronic properties of the nanocomposites by hybridization of the graphene and to the addition of Ag/AgI which generates a strong surface plasmon resonance effect in the metallic silver further improving the photocatalytic activity and stability under solar irradiation. Scavenger experiments suggest that superoxide and hydroxyl radicals are responsible for the photodegradation of Congo red. Our findings are important for the fundamental understanding of the photocatalytic mechanism of ZnO/graphene/Ag/AgI nanocomposites and can lead to further development of novel efficient photocatalyst materials.

High-efficiency of plasmonic ZnO/graphene/Ag/AgI nanocomposites for solar-driven photocatalysis activities.