Photocatalytic Degradation Performance Research Articles

Photocatalytic PAN Nanofibrous Membrane through Anchoring a Nanoflower-Branched CoAl-LDH@PANI Heterojunction for Organic Hazards Degradation and Oil-Containing Emulsified Wastewater Separation.

The synergistic treatment of oily wastewater containing organic hazards and emulsified oils remains a big challenge for membrane separation technology. Herein, the photocatalytic membrane, which combined the physical barrier and catalytic oxidation-driven degradation functionality, was fabricated via anchoring a nanoflower-branched CoAl-LDH@PANI Z-scheme heterojunction onto a porous polyacrylonitrile mat and using tannic acid as an adhesive. The assembly of such a Z-scheme heterojunction offered the superior photocatalytic degradation performance of soluble dyes and tetracycline (up to 94.3%) to the membrane with the improved photocatalytic activity of 2.33 times compared with the CoAl-LDH@pPAN membrane. Quenching experiments suggested that the •O2- was the most reactive oxygen species in the catalytic reaction system of the composite membrane. The greatly enhanced photocatalytic activity was attributed to the effective inhibition of photogenerated hole-electron combination using PANI as a carrier, with charge transferring from LDH to PANI. The possible photocatalytic degradation mechanism was proposed based on VB-XPS, electron spin resonance spectroscopy, and DRS technologies, which was confirmed by density functional theory calculation. Meanwhile, benefiting from the superhydrophilic/oleophobic feature and low oil adhesion, the membrane exhibited high permeability for isooctane emulsion (3990.39 L·m-2·h-1), high structure stability, and satisfactory cycling performance. This work provided a strategy to develop superwetting and photocatalytic composite membranes for treating complex multicomponent pollutants in the chemical industry.

Construction of Rod-Like Bi4O5I2/NaYF4:Yb,Tm Composite and its Improved Photocatalytic Degradation Performance Under Near-Infrared Light

Photocatalytic technology exhibits promising prospects in environmental remediation owing to its sustainable and environmentally friendly advantages. Among the bismuth-rich halide oxides, Bi4O5I2 has demonstrated remarkable efficacy in dye degradation due to its favorable valence band and conduction band positions. In this study, we successfully synthesized Bi4O5I2/NaYF4:Yb,Tm composites through a solvothermal method. When exposed to visible light, the Bi4O5I2/NaYF4:Yb,Tm composite achieved an impressive degradation rate of 86.7% for RhB solution after 60[Formula: see text]min of light-induced reaction. Moreover, the incorporation of NaYF4:Yb,Tm into Bi4O5I2 extended the utilization of near-infrared (NIR) spectroscopy. Under 980[Formula: see text]nm NIR light irradiation, the degradation rate of Rhodamine B (RhB) solution by the Bi4O5I2/NaYF4:Yb,Tm composite reached 43.0% after 240[Formula: see text]min of light reaction. Free radical capture experiments confirmed that h[Formula: see text] and •[Formula: see text] O[Formula: see text] played a significant role as the primary active species in the degradation process of RhB by the Bi4O5I2/NaYF4:Yb,Tm composites. Furthermore, we explored the mechanism behind the photocatalytic degradation of RhB solution using the Bi4O5I2/NaYF4:Yb,Tm composites. Bi4O5I2/NaYF4:Yb,Tm holds great potential as a promising candidate for utilization of NIR light for photocatalytic reactions.

Preparation and photocatalytic performance of BiOCl nanosheet–TiO2 nanotube array composites

Combining BiOCl with TiO2 nanomaterials is beneficial to enhance the photocatalytic activity and optoelectronic activity. In this paper, BiOCl nanosheet–TiO2 nanotube array composites were synthesized to enhance the photocatalytic degradation performance for methyl orange (MO) of TiO2 under ultraviolet light irradiation. BiOCl nanosheets were deposited on TiO2 nanotube arrays by the straightforward impregnation method. X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, and photocurrent (i–t) were used to evaluate the composites of BiOCl nanosheets–TiO2 nanotube arrays. The results showed that the tetragonal BiOCl nanosheets clustered together on the surface of the TiO2 nanotubes and grew along the (110) crystal plane. The composites outperformed pure TiO2 regarding outstanding structure and overall photocatalytic performance, and the MO photocatalytic degradation rate was 98.5%. For the 30-BiOCl–TiO2, its photocurrent intensity (58 µA) was 4.5 higher than TiO2 (13 µA). The degradation rate of 87% can still be reached after three cycles.

Optimization of Synthesizing Conditions for MXene (Ti3C2) Photocatalyst: Effect of LiF:Ti3AlC2 Mass Ratio

The analysis of the proposed work, specifically the development of the MXene photocatalyst, will be described in this chapter. The results of the analysis are useful for comparing the pristine precursor and etched structures of the MXene photocatalyst. A minimally intensive layer delamination (MILD) method will be used to create the MXene photocatalyst which uses lower fluorine content solution (HCl-LiF) creating a safer and easier method. The synthesis parameters for the development of highly efficient MXene photocatalysts, such as LiF:Ti3AlC2 mass ratio will be optimized. FTIR, XRD, SAP, FESEM and DR UV-Vis analysis will be used to characterize the as-developed MXene photocatalyst and its precursor, Ti3AlC2. The hypothesis of this study is etching treatment will increase the hydrophilicity and active functional group such as oxygen (O), fluorine (F) and hydroxyl (-OH) on MXene surfaces. The performance of photocatalytic degradation will be tested with an initial dye concentration of 30 ppm, solution pH at pH7 at room temperature (±27 ̊C). Each photocatalytic degradation study was performed in 50 ml of methylene blue solution with 0.1 g photocatalyst. All developed MXenes will undergo photocatalytic degradation performance to identify the optimized synthesizing conditions. The highest MXene photodegradation performance was found to reach 90% removal within 180 min.

Construction of Co3O4/Bi5O7I heterojunction derived from ZIF-67/BiOI with enhanced photodegradation ability

Recently, the degradation of expired and unused antibiotics has been a great concern for human health, and it has become a serious environmental hazard. Photocatalysis technology has treated the most promising ways to degrade antibiotics in the environment with high efficiency and low cost. A series of Co3O4/Bi5O7I composites were successfully synthesized via the calcination method derived from Zeolitic imidazolate frameworks-67 and Bismuth oxyiodide, and chatacerized by spectroscopic and also X-ray diffraction (XRD) processes. Co3O4/Bi5O7I composites exhibited enhanced photocatalytic performance for tetracycline degradation, which is about 6 times higher than that of the pristine Co3O4. The Co3O4/Bi5O7I can remove 86.67% tetracycline in 90 min and shows enhanced photocatalytic activities, which are about 6 times higher than those of the pristine Co3O4. The possible mechanisms of photocatalytic degradation were analyzed by trapping experiments, electron paramagnetic resonance, photocurrent, and electrochemical impedance measurements. The direct Z-scheme structure of Co3O4/Bi5O7I composites facilitated the charge separation and transportation of the photogenerated electrons and holes.

Construction of MoS2/BN nanohybrids with enhanced photocatalytic performance for RhB and TC degradation

In this study, MoS2/boron nitride nanohybrids have been fabricated via a simple hydrothermal process. Highly efficient nanohybrids have been synthesized by adding boron nitride (BN) as interfacial charge carrier migrate mediators onto the MoS2. The MoS2/BN nanohybrids exhibit excellent photocatalytic efficiency for removing rhodamine B (RhB) and tetracycline (TC) pollutants. The MoS2/BN nanohybrids show the best rate constant of 0.07 min−1, which is 1.5 folds greater than MoS2. Besides, MoS2/BN nanohybrids exhibit excellent cycling stability. The conformable improved mechanism for MoS2/BN-10 % nanohybrids could be assigned to the useful interfacial charge carrier separation and transfer between MoS2 and BN. The investigative results exhibited that the heterostructures presented better photocatalytic performance than the bare MoS2, and a slight proportion of the BN sample was favorable for photoinduced electron-hole pairs separation, which can improve the photocatalytic efficiency of MoS2/BN nanohybrids. This study displayed a facile process for the reasonable design of photocatalysts by developing their heterostructure and application.

Nanoarchitectonics of bamboo-based heterojunction photocatalyst for effective removal of organic pollutants

A high-performance photocatalyst with both efficient and reusable performance is essentially demanded for the purification of organic wastewater and the removal of indoor formaldehyde. However, recovery of photocatalyst particles from the reaction system remains a challenge. Herein, based on the abundant pore structure of natural bamboo and the outstanding photocatalytic activity of ZnO/WO3, we fabricated an efficient bamboo-based photocatalyst (ZnO/WO3@bamboo) for the efficient photocatalytic degradation of formaldehyde and organic dyes. The pretreatment of bamboo substrates with NaOH solution resulted in the formation of nucleation sites for ZnO/WO3 growth within bamboo cellulose channels. Subsequently, the as-prepared ZnO and WO3 were mixed in different mass ratios, and loaded on the pretreated bamboo substrates using the hydrothermal method. The results showed that the ZnO/WO3@bamboo had the effective function of photocatalytic degradation of formaldehyde gas and organic dyes. Moreover, the as-prepared ZnO/WO3@bamboo photocatalyst demonstrated superior recycling ability toward organic pollutants, which was described by photocatalytic degradation efficiency of formaldehyde gas more than 89% after 10 cycles, and organic dyes over 93% after 20 cycles. The coupling of ZnO and WO3 leads to electron delocalization, which caused the electron holes generated in the valence band (VB) of ZnO to delocalize to the VB of WO3, and reduced the recombination of electron-hole. Therefore, the photocatalytic degradation performance of the ZnO/WO3@bamboo was enhanced. The proposed ZnO/WO3@bamboo photocatalyst holds great promise in the field of air pollution and wastewater remediation.

A Tight-Connection g-C3N4/BiOBr (001) S-Scheme Heterojunction Photocatalyst for Boosting Photocatalytic Degradation of Organic Pollutants.

The efficient separation of photogenerated charge carriers and strong oxidizing properties can improve photocatalytic performance. Here, we combine the construction of a tightly connected S-scheme heterojunction with the exposure of an active crystal plane to prepare g-C3N4/BiOBr for the degradation of high-concentration organic pollutants. This strategy effectively improves the separation efficiency of photogenerated carriers and the number of active sites. Notably, the synthesized g-C3N4/BiOBr displays excellent photocatalytic degradation activity towards various organic pollutants, including methylene blue (MB, 90.8%), congo red (CR, 99.2%), and tetracycline (TC, 89%). Furthermore, the photocatalytic degradation performance of g-C3N4/BiOBr for MB maintains 80% efficiency under natural water quality (tap water, lake water, river water), and a wide pH range (pH = 4-10). Its excellent photocatalytic activity is attributed to the tight connection between g-C3N4 and BiOBr in the S-scheme heterojunction interface, as well as the exposure of highly active (001) crystal planes. These improve the efficiency of the separation of photogenerated carriers, and maintain their strong oxidation capability. This work presents a simple approach to improving the separation of electrons and holes by tightly combining two components within a heterojunction.

Supermolecule polymer derived of carbon nitride with controllable nanosheet for enhancing the degradation performance of RhB and BPA

Using melamine-cyanuric acid (MCA) supramolecular polymer as a precursor, a method was employed to synthesize graphitic carbon nitride with a large specific surface area and controllable band structure. The band structure and morphology of graphitic carbon nitride (g-C3N4) are closely related to the type of solvent used. By treating it with hypophosphorous acid and subsequent high-temperature treatment for 10 h , the precursor material was calcined to produce graphitic carbon nitride with a hollow tubular morphology. Experimental results demonstrate that this material exhibits outstanding performance in photocatalytic degradation of Rhodamine B and Bisphenol A. This work provides a new and effective strategy for achieving visible-light photocatalytic degradation of organic compounds.

FeOOH Nanosheets Coupled with ZnCdS Nanoparticles for Highly Improved Photocatalytic Degradation of Organic Dyes and Tetracycline in Water.

Developing a low-cost and highly efficient semiconductor photocatalyst for the decomposition of organic pollutants and antibiotics is highly desirable. Herein, FeOOH nanosheets were prepared using a liquid-phase stirring technique and combined with ZnCdS (ZCS) nanoparticles to construct FeOOH/ZCS nanocomposite photocatalysts. The photocatalytic efficiency of the FeOOH/ZCS nanocomposite was evaluated for the decomposition of various pollutants, including rhodamine B, methylene Blue, and tetracycline. The FeOOH/ZCS nanocomposite exhibited significantly higher photocatalytic performance for the decomposition of various organics. Moreover, the optimized FeOOH/ZCS retained more than 90% of its initial photocatalytic activity even after five successful runs. Radical quenching test and electron spin resonance (ESR) analysis revealed that hydroxyl radicals (•OH) play a dominant role for the decomposition of organics. The FeOOH/ZCS Z-scheme heterojunction significantly facilitates higher charge transfer efficiency and the generation of reactive radicals, resulting in excellent photocatalytic degradation performance. This work offers a new approach to synthesis FeOOH-based photocatalyst for the elimination of organics and antibiotics in water.

Rapid photocatalytic dye degradation, enhanced antibacterial and antifungal activities of silver stacked zinc oxide garnished on carbon nanotubes

A composite of Zinc oxide loaded with 5-weight % silver decorated on carbon nanotubes (Ag-loaded ZnO: CNT) was synthesized using a simple refluxed chemical method. The influence of deviation in the weight % of carbon nanotube loading on photocatalytic dye degradation (methylene blue and rose bengal) and antibiotic (antimicrobial and antifungal) performance was investigated in this study. The light capture ability of Ag-loaded ZnO:CNT in the visible region was higher in photocatalytic activity than that of Ag-loaded ZnO and ZnO:CNT. The bandgap of the Ag-loaded ZnO: CNT was tuned owing to the surface plasmon resonance effect. The photocatalytic degradation investigations were optimized by varying the wt% in CNTs, pH of dye solution, concentration of the dye solution, and amount of catalytic dose. Around 100% photocatalytic efficiency in 2 min against MB dye was observed for Ag doped ZnO with 10 wt% CNT composite at pH 9, at a rate constant 1.48 min−1. Bipolaris sorokiniana fungus was first time tested against a composite material, which demonstrated optimum fungal inhibition efficiency of 48%. They were also tested against the bacterial strains Staphylococcus aureus, Bacillus cerius, Proteus vulgaris, and Salmonella typhimurium, which showed promising antibacterial activity compared to commercially available drugs. The composite of Ag doped ZnO with 5 wt% CNT has shown competitive zone inhibition efficacy of 21.66 ± 0.57, 15.66 ± 0.57, 13.66 ± 0.57 against bacterial strains Bacillus cerius, Proteus vulgaris, and Salmonella typhimurium which were tested for the first time against Ag-loaded ZnO:CNT.

Construction of oxygen-doped g-C3N4/BiOCl (S-scheme) heterojunction: Efficient degradation of tetracycline in wastewater

Graphitic phase carbon nitride (g-C3N4) demonstrates significant promise in the photocatalytic degradation of organic pollutants, but the rapid recombination of photogenerated electron-hole pairs seriously restricts its degradation capacity. In this study, an innovative heterostructural anion regulation strategy based on g-C3N4 was proposed to significantly enhance the degradation performance of tetracycline. Initially, we regulated the electron configuration of g-C3N4 through O doping to optimize the active sites at the reaction interface. Subsequently, the S-scheme heterojunction was constructed by introducing BiOCl to stimulate the pumping effect and form efficient build-in electric field electron channels. The oxygen-doped g-C3N4/BiOCl (OCN/BiOCl) heterojunction material obtained through aforementioned modification exhibited a degradation efficiency of 89.33 % towards 20 mg·L−1 tetracycline (90 min light reaction, 30 min dark reaction), which was 2.5 times that of conventional g-C3N4 catalyst. In particular, density functional theory calculations and ultraviolet photoelectron spectroscopy jointly revealed the unique chemical environment and electronic structure between OCN and BiOCl due to the formation of the build-in electric field, thereby providing enhanced pathways for the migration of photogenerated currents. Meanwhile, the heterostructure significantly reduced the transport distance of photo-induced charge and minimizes the internal transmission resistance. It enhances the efficiency of separating photogenerated electrons and hole pairs, which is the key mechanism for greatly improving the photocatalytic degradation performance of OCN/BiOCl materials. In summary, the hetero-anion regulation strategy proposed in this study addresses the issue of rapid recombination of photogenerated charges in g-C3N4, providing a new perspective for efficient control of organic pollutants in the environment driven by g-C3N4 photocatalyst.

A novel LaFeO3/g-C3N4/Ag3PO4 dual Z-scheme heterojunction with enhanced light absorption, charge carrier separation and transfer capacity for photodegradation of antibiotics

The effective separation of photogenerated carriers is still a key problem to be overcome in the preparation of efficient green photocatalysts. In this work, A novel ternary composite LaFeO3/g-C3N4/Ag3PO4 (LgA) with dual Z-scheme heterojunction structure photocatalyst was constructed by combining LaFeO3 with excellent photoelectric conversion rate and Ag3PO4 with high-quantum yield on the surface of g-C3N4 by electrostatic attraction and in-situ co-precipitation. The serial characterization confirmed that there were close heterojunction interfaces and well-matched band structures among them, which was conducive to improving the separation efficiency of photogenerated electron-hole pairs. The photocatalytic results showed that the photocatalytic degradation performance of LgA-4 composites for ciprofloxacin hydrochloride (HCIP) was significantly superior to that of g-C3N4, LaFeO3, Ag3PO4 or their binary composites, and the degradation efficiency could reach 90.2 %, which could be mainly attributed to the construction of dual Z-scheme heterojunction with large valence bands oxidation surface, improved the light absorption capacity and promoted the separation of photogenerated electron-hole pairs (e−-h+). LgA-4 also had good stability and efficient universality. Furthermore, the photocatalytic mechanism of HCIP photocatalytic degradation by LgA-4 heterojunction was particularly discussed according to the results of characterization, free radical quenching and ESR experiments. The potential degradation pathways for HCIP by LgA-4 were proposed as well based on the degradation intermediates detected by Ultra-high Performance Liquid Chromatography-Mass Spectroscopy (UPLC-MS), HCIP degradation was confirmed a process of reduced ecotoxicity. These results provided a facile pathway for the preparation and application of high efficiency photocatalysts in water pollution control.

Photodegradation of dye wastewater by Ti doped Bi2O3/montmorillonite composites

Ti-doped Bi2O3/montmorillonite composites (TBM) were synthesized via chemical solution decomposition using tetrabutyl titanate and bismuth nitrate pentahydrate as titanium and bismuth sources, with sodium montmorillonite as the carrier. The active brilliant blue KN-R, carmine, and rose red B solutions were employed for adsorption and degradation experiments. Characterization of the composite was done through XRD, SEM, BET, and UV-Vis DRS analyses. Results indicate that the optimal degradation performance is achieved when the Ti doping ratio is 4 % (4TBM). The removal rates for active brilliant blue KN-R, carmine, and rose red B solutions were 98.17 %, 98.29 %, and 96.77 %, respectively. Bi2O3 was found in a tetragonal phase, with Ti ions doping into the lattice of Bi2O3 as Ti4+ inhibiting grain growth. The montmorillonite flakes in the composite were exfoliated, leading to an increased specific surface area of 4.16 m2/g. Following Ti doping, Ti 3d, O 2p, and Bi 6 s orbitals combined to form a valence band of 4TBM, reducing the band gap from 2.59 eV to 2.52 eV. This enhancement in light absorption capacity improved the photocatalytic degradation performance of 4TBM.

Directional regulation of reactive oxygen species in titanium dioxide boosting the photocatalytic degradation performance of azo dyes

It has been widely accepted that the generation of reactive oxygen species such as superoxide radical, hydroxyl radical, and hydrogen peroxide during photocatalysis is responsible for the degradation of azo dyes. However, it is unclear which reactive oxygen species primarily contributes to the degradation efficiency of azo dyes. Here, we demonstrate that the directional regulation of reactive oxygen species in titanium dioxide (TiO2) to form superoxide radicals by ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) can significantly improve the degradation performance of methyl orange. The optimized addition of EDTA-2Na can completely degrade azo dyes such as methyl orange, acid orange and alkaline orange at a concentration of 10 mg/L in about 20 min, which is not only higher than that achieved by pristine TiO2 under Xe lamp light but also far superior to the reported degradation efficiency of modified TiO2. Even under natural sunlight, this strategy can also effectively decompose azo dyes, demonstrating the great potential for practical water treatment using low-cost TiO2 photocatalysts.

One-step thermal oxidation synthesis of carbon-doped TiO2 with enhanced photocatalytic activity using CO2 as the carbon source

The study proposed a simplified carbon doping synthesis strategy to enhance the photocatalytic activity of titanium dioxide (TiO2). Utilizing CO2 gas as the carbon source, the material was directly synthesized onto a titanium substrate through a one-step thermal oxidation method. Raman and XPS analyses indicated that with the increase in CO2 partial pressure, the influence of the carbon source was amplified, resulting in carbon doping in a graphite-like structure and the induction of oxygen vacancies. Electrochemical impedance spectroscopy and UV–vis spectra demonstrated that the introduced carbon species acted as a photosensitizer, augmenting the transfer of photogenerated carriers. Photoluminescence spectra suggested that oxygen vacancies could enhance the non-radiative scattering of photogenerated carriers. These two effects synergistically improved the photocatalytic activity of TiO2 significantly, although the degree of enhancement was dependent on the optimized ratio of carbon content to oxygen vacancy content. Only with optimal carbon content and oxygen vacancy levels could the undesired radiative recombination of photogenerated carriers be prevented, ensuring that the energy derived from visible light was effectively utilized to drive chemical reactions. Under these optimal conditions, the TC-O5 and TC-O10 samples exhibited excellent photocatalytic degradation performance of methyl orange under visible light, with degradation rates of 86.27% and 82.54%, respectively, and displayed outstanding cycling stability, with the degradation rate remaining above 90% for three cycles. This method proved to be simple, efficient, and easily operable, offering significant advantages for industrial-scale preparation.

Remarkable improvement in photocatalytic activity of NiO nanoparticles through Ag doping: A kinetics-mechanism & recyclability

Metal oxides are recognized as exemplary materials for photocatalytic dye degradation attributed to their unique characteristics such as tunable electronic structure, prolonged stability, and cost-effectiveness. However, the wide band gap inherent to most of these materials often limits their light absorption to the ultraviolet (UV) region. Consequently, the doping of noble metal nanoparticles into the metal oxide nanostructures has been proposed to significantly improve their light-harvesting ability. This enhancement is primarily ascribed to the localized surface plasmon resonance (LSPR) effect associated with noble metal nanoparticles, which facilitates more effective utilization of light. Thus, in this study, we synthesized silver-doped nickel oxide (Ag:NiO) with varying Ag concentrations (0, 1, 2, 4, 6 wt%) to evaluate their photocatalytic performance. The X-ray diffraction (XRD) spectra revealed that NiO possesses a cubic crystalline structure, and a peak shift to a higher angle was noted for Ag doping, indicative of compressive strain. Further analyses of morphological, vibrational, and absorption properties were conducted through the acquisition of scanning electron microscopy (SEM) images, Raman spectra and UV–Vis absorption spectra, respectively. The photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) dyes was assessed, revealing that NiO with 4.wt.% Ag doping exhibited enhanced photocatalytic activity, achieving 99% degradation of MB and 90% degradation of RhB. Notably, Ag doping significantly enhances the light absorption capabilities and modifies the electronic structure of the NiO, thereby improving its performance in photocatalytic dye degradation.

PVA hydrogel serve as a high-efficiency carrier to enhance the photocatalytic degradation performance of BiOBr

BiOBr is a bismuth-containing photocatalytic material that exhibits visible light activity, making it highly promising for applications in photocatalytic degradation of pollutants and ecological protection. However, its application is hinder by the powder form and small particle size. Loading a powder photocatalyst on a suitable carrier is a common way to solve this challenge. This study proposes that PVA hydrogel can be used as a highly efficient carrier to enhance the photocatalytic degradation performance of BiOBr. By adding a foaming agent, the pore structure of hydrogel was improved and the degradation performance to pollutants in wastewater was increased. The impact of various factors, including BiOBr photocatalyst loading, solution pH, recycling stability, and reactive species, on the photocatalytic degradation process were investigated. The performance of the PVA/BiOBr composite hydrogel to degrade methylene blue (MB) under simulated solar irradiation was studied. After a 120 min photocatalytic reaction, PVA/BiOBr-1.0 % composite hydrogel removed 99 % of 10 mg·L−1 MB, which was superior to pure BiOBr photocatalyst. This investigation is of significance as it provides insights into the integration of BiOBr catalysts key role of the PVA hydrogel carriers in enhancing the catalytic performance of BiOBr photocatalyst in wastewater treatment.

Investigation of photocatalytic and visible light self-cleaning performance of 2D/2D g-C3N4-ZrO2 based PES/PDA membranes for organic contaminants degradation

This study fabricated a novel photocatalytic, self-cleaning membrane by depositing a 2D-2D g-C3N4/ZrO2 photocatalyst on polydopamine-coated polyethersulfone. The morphologies and surface chemistry of the membranes were studied through FESEM-EDX, AFM, and XPS. The results showed the satisfactory binding stability of the photocatalyst on the polyethersulfone/polydopamine. Also, depositing of the photocatalyst on the polyethersulfone/polydopamine strongly enhanced hydrophilicity. The optimized photocatalytic membrane (39.68 Lm2h) had a substantially higher water flux than polyethersulfone (13.61 Lm2h) and polyethersulfone/polydopamine (19.42 Lm2h). The photocatalytic membranes showed high dye removal and protein rejection rates. The flux recovery ratio was 83.32 % after 30 min of visible-light exposure. The conversion of irreversible contaminants into reversible ones under visible-light demonstrated the self-cleaning nature of the membrane. In addition, the photocatalytic membrane showed substantial stability in the vibration and shear force tests. Therefore, the polyethersulfone/polydopamine/(g-C3N4/ZrO2) membrane is a promising candidate for removing organic contaminants from water due to high rejection, water flux rate, and satisfactory stability. This study not only proposed an efficient methodology to fabricate a novel photocatalytic self-cleaning membrane with high stability but also provided further insights into the effects of the 2D structure of photocatalyst on the flux and photocatalytic degradation performance of such membranes.

The photocatalytic degradation performance of Dion-Jacobson-type layered perovskites AMCa2Ta3O10 (AM=Rb, Cs): A DFT study

The structural, electronic, redox potential, mechanical, photocatalytic, and optical properties of the Dion-Jacobson-type triple-layered perovskites AMCa2Ta3O10 (AM = Rb, Cs) are investigated via density functional theory (DFT) study. The electronic properties are calculated through HSE-06 functional technique which confirmed the semiconducting behavior with the energy band gap values of 1.67 eV and 1.71 eV for RbCa2Ta3O10 and CsCa2Ta3O10, respectively. The calculated results of redox potential indicate that both materials are favorable for water splitting and as an agent for pollutant degradation. Both studied compounds exhibit a reduced effective mass of electrons, which suggests the high capacity to transfer the charge to the surface, indicative of superior electrical conductivity. Poisson's and Pugh's ratios suggest that both the materials are brittle. Optical parameters are calculated within the energy range of 0–6 eV, which strongly correlates with the energy band gap's high absorption and low reflection in the visible region. Our findings indicate high photocatalytic efficiency in organic pollutant degradation, suggesting the potential for developing advanced photocatalytic devices for water splitting and environmental pollutant decomposition.