Nanocomposite Photocatalyst Research Articles

Functionalized cements incorporated with nanocomposite photocatalysts for self-cleaning applications

The constantly escalating pollution on the surface of cement-based materials affects architectural aesthetics and residents′ health, necessitating frequent cleaning and maintenance, which contradicts the concept of sustainable development. This study aimed to develop a novel photocatalytic cement material to enhance the self-cleaning capabilities of cement-based materials, thereby extending their service life and reducing maintenance costs. To achieve this, carbon quantum dots (CDs) and g-C3N4 (CN) nanocomposite photocatalysts (CDs@CN) were synthesized and integrated into white cement to prepare photocatalytic cements. The materials were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscopy. Photocatalytic performance was evaluated by the degradation of Rhodamine B (RhB) under xenon (Xe) lamp, Vis light and UV light. The CDs@CN nanocomposite displayed superior photocatalytic activity, particularly under Xe lamp irradiation, achieving over 95 % degradation of RhB within 1 h. Even under Vis and UV light, the photocatalytic cement retains robust self-cleaning capabilities, achieving pollutant degradation rates of 81 % and 63 %, respectively, within 1 h. This performance exceeded that of pristine CN and control samples, demonstrating effective light absorption and charge separation. The optimal photocatalyst concentration in cement was identified as 0.1∼5.0 wt%, balancing performance and dispersion. The developed CDs@CN-based photocatalytic cement material offers a sustainable solution for self-cleaning and environmental purification. This study provides insights into the design of functional cementitious materials and contributes to the sustainable development of the construction industry.

Solar driven highly efficient photocatalyst based on Dy2O3 nanorods deposited on reduced graphene oxide nanocomposite for methylene blue dye degradation.

In recent years, the demand for rare earth elements has surged due to their unique characteristics and diverse applications. This investigation focuses on utilizing the rare earth element dysprosium oxide (Dy2O3) for the photocatalytic oxidation of model pollutants under solar light irradiation. A novel RGO-Dy2O3 nanocomposite photocatalyst was developed using a solvothermal approach, Dy2O3 nanorods uniformly deposited onto reduced graphene oxide (RGO) nanosheets. Comprehensive characterization techniques, including Brunner-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), Raman spectroscopy, high resolution - transmittance electron microscopy (HR-TEM), field emission-electron scanning microscopy (FE-SEM), atomic force microscopy (AFM), electron paramagnetic resonance spectroscopy (EPR), photoluminescence spectroscopy (PL), and electrochemical impedance spectroscopy EIS techniques. The UV-visible diffusive reflectance spectroscopy (UV-Vis-DRS) studies revealed a band gap energy of 3.18eV and a specific surface area of 114 m2/g for the fabricated RGO-Dy2O3 nanocomposite. The RGO-Dy2O3 nanocomposite demonstrated a high photocatalytic degradation efficiency of 98.1% at neutral pH for methylene blue (MB) dye for the dye concentration of 10ppm. The remarkable photocatalytic performance was achieved within 60min under solar light irradiation. Reusability tests demonstrated stability, maintaining over 90% photocatalytic efficiency after three cycles. The EPR spectra and quenching experiments confirmed that photogenerated hydroxyl radicals significantly influence the photodegradation processes. The RGO-Dy2O3 nanocomposite photocatalyst, with its green, easy preparation process and recycling capabilities, presents an ideal choice for various applications. It offers a viable alternative for the photocatalytic degradation of organic dyes in real wastewater, contributing to sustainable environmental remediation.

Anchoring TiO2 and CuO nanoparticles on SnO2 nanotube arrays to construct ternary heterostructure for visible-light-driven photocatalytic degradation of green malachite dye

Designing and constructing heterostructure photocatalysts is necessary to facilitate the long-term separation of photogenerated charge carriers and enhance photocatalytic efficiency. Herein, a ternary nanocomposite photocatalyst based on SnO2, TiO2 and CuO semiconductors was successfully synthesized and employed as a highly effective photocatalyst for the malachite green (MG) dye degradation under visible light irradiation. According to the results, the ternary SnO2/TiO2/CuO nanocomposite demonstrated impressive photocatalytic activity (98.4 %) compared to pristine SnO2 nanotubes (40.3 %), binary SnO2/TiO2 (76 %) and SnO2/CuO nanocomposites (88 %), when exposed to 90 min of visible illumination. The photoreaction rate constant of SnO2/TiO2/CuO nanocomposite (0.0482 min−1) was found to be ∼8.5 times faster than SnO2 nanotubes (0.0057 min−1) against MG dye. This enhancement in photocatalytic performance can be attributed to the introduction of TiO2 and CuO which effectively suppress the recombination of photogenerated electron-hole pairs, accelerate the transfer of charge carriers, increase the active sites, and improve the optical absorption properties. Scavengers were used to elucidate the photocatalytic mechanism, exhibiting the pivotal role of •O2− and h+ in the photodegradation process. Besides, recyclability tests showed acceptable results after four cycles, confirming the stability and durability of the SnO2/TiO2/CuO nanocomposite against RhB dye degradation.

Cu surface plasmon resonance promoted charge transfer in S-scheme system enhanced visible light photocatalytic hydrogen evolution

Reasonably constructing nanocomposite photocatalysts with fast charge transfer and broad solar response capabilities is significant for efficiently converting solar energy into chemical energy. Cu modifies P25/CeO2 heterojunctions prepared by photodeposition (P25 is commercial TiO2). The local surface plasmon resonance (LSPR) effect caused by Cu nanoparticles broadens the spectral response range and generates significant photothermal effects. After 90 s of irradiation, the temperature of 9.5 %Cu-P25/CeO2 increases to 148.1 °C. The photocatalytic hydrogen evolution rate (HER) of 9.5 %Cu-P25/CeO2 under visible light (λ = 400 nm) reaches 1538.2 μmol h−1 g−1, which is 158.6 times, 17.7 times, and 2.5 times higher than that of Cerium dioxide (CeO2), P25, and P25/CeO2, respectively. This catalyst has stronger light absorption, easier carrier transfer, and separation. This study guides the construction of efficient hydrogen evolution photocatalysts.

Photocatalytic degradation of phenol and polycyclic aromatic hydrocarbons in water by novel acid soluble collagen-polyvinylpyrrolidone polymer embedded in Nitrogen-TiO2

Herein, we have synthesized acid-soluble collagen (ASC), polyvinylpyrrolidone (PVP), and nitrogen-doped titanium dioxide to form a novel hybrid photocatalyst nanocomposite (N-TiO2/ASC-PVP). The results of XRD, SEM and TEM revealed that the as-synthesized photocatalyst was composed of spheroidal particles, which were smaller than undoped TiO2.XPS analysis revealed that N was effectively incorporated into the lattice of TiO2 through substituting oxygen atoms, and N might coexist in the form of substitutional N (O–Ti–N) and interstitial N (TiON). The N-TiO2/ASC-PVP composite calcined at 200 and 400 °C exhibited high photocatalytic degradation rates for phenol, naphthalene (Nap), fluoranthene (Flu), phenanthrene (Phe), pyrene (Pyr), benz[a]anthracene (BaA), and anthracene (Ana), achieving a 98.6 % removal rate within 120 min at a dosage of 10 mg/L. The enhanced visible light photocatalytic activity was mainly attributed to the smaller crystal size, more surface hydroxyl groups, stronger light absorption in visible region and narrower band gap energy. This innovative hybrid photocatalyst holds immense potential for applications in materials science and nanotechnology, promising to revolutionize various industries.

Extended Interfacial Charge Transference in CoFe2O4/WO3 Nanocomposites for the Photocatalytic Degradation of Tetracycline Antibiotics.

The large-scale utilization of antibiotics has opened a separate chapter of pollution with the generation of reactive drug-resistant bacteria. To deal with this, in this work, different mass ratios of CoFe2O4/WO3 nanocomposites were prepared following an in situ growth method using the precursors of WO3 and CoFe2O4. The structure, morphology, and optical properties of the nanocomposite photocatalysts were scrutinized by X-ray diffraction (XRD), UV-visible diffuse reflectance spectra (UV-Vis DRS), photoluminescence spectrum (PL), etc. The experimental data signified that the loading of CoFe2O4 obviously changed the optical properties of WO3. The photocatalytic performance of CoFe2O4/WO3 composites was investigated by considering tetracycline as a potential pollutant. The outcome of the analyzed data exposed that the CoFe2O4/WO3 composite with a mass ratio of 5% had the best degradation performance for tetracycline eradication under the solar light, and a degradation efficiency of 77% was achieved in 20 min. The monitored degradation efficiency of the optimized photocatalyst was 45% higher compared with the degradation efficiency of 32% for pure WO3. Capturing experiments and tests revealed that hydroxyl radical (·OH) and hole (h+) were the primary eradicators of the target pollutant. This study demonstrates that a proper mass of CoFe2O4 can significantly push WO3 for enhanced eradication of waterborne pollutants.

Visible-light-driven selective cleavage of lignin C-C bonds on the TiO2@g-C3N4 heterostructured photocatalyst.

The selective cleavage of lignin C-C bonds is a highly sought-after process with the goal of obtaining low-molecular-weight aromatic chemicals from renewable resources. However, it remains a challenging task to achieve under mild conditions. Photocatalysis is a potentially promising approach to address this issue, but the development of efficient photocatalysts is still in progress. In this study, we introduce the heterostructured TiO2@g-C3N4 photocatalyst for the development of a visible light photocatalytic procedure for the selective cleavage of lignin C-C bonds under mild conditions. The photocatalyst displays favourable visible light absorption, efficient charge separation efficiency, and promising reusability. A typical β-O-4 dimer model, 2-phenoxy-1-phenylethanol, was effectively (96.0% conversion) and selectively (95.0 selectivity) cleaved under visible light at ambient conditions. This photocatalytic procedure was also effective when subjected to solar irradiation or other lignin dimer models with β-O-4 or β-1 linkages. This reaction occurred through a Cβ-centred radical intermediate and a six-membered transition state with photogenerated holes as the primary active species. The Cα-OH oxidative dehydrogenation of the substrate could also take place but was a relatively minor route. This study provides a new photocatalytic procedure for visible-light-driven lignin valorisation and sheds light on the design of high-performance nanocomposite photocatalysts for C-C bond cleavage.&#xD.

Investigation of MO Adsorption Kinetics and Photocatalytic Degradation Utilizing Hollow Fibers of Cu-CuO/TiO2 Nanocomposite.

This comprehensive study explores the kinetics of adsorption and its photocatalytic degradation of methyl orange (MO) using an advanced copper-decorated photocatalyst in the form of hollow fibers (HFs). Designed to boost both adsorption capacity and photocatalytic activity, the photocatalyst was tested in batch experiments to efficiently remove MO from aqueous solutions. Various isotherm models, including Langmuir, Freundlich, Sips, Temkin, and Dubinin-Radushkevich, along with kinetic models like pseudo-first and pseudo-second order, Elovich, Bangham, and Weber-Morris, were utilized to assess adsorption capacity and kinetics at varying initial concentrations. The results indicated a favorable MO physisorption on the nanocomposite photocatalyst under specific conditions. Further analysis of photocatalytic degradation under UV exposure revealed that the material maintained high degradation efficiency and stability across different MO concentrations. Through the facilitation of reactive oxygen species generation, oxygen played a crucial role in enhancing photocatalytic performance, while the degradation process following the Langmuir-Hinshelwood model. The study also confirmed the robustness and sustained activity of the nanocomposite photocatalyst, which could be regenerated and reused over five successive cycles, maintaining 92% of their initial performance at concentrations up to 15 mg/L. Overall, this effective nanocomposite photocatalyst structured in the form of HF shows great promise for effectively removing organic pollutants through combined adsorption and photocatalysis, offering valuable potential in wastewater treatment and environmental remediation.

ZnO/carbon quantum dots nanocomposites derived from Moringa oleifera gum: An improved catalytic vitiation of methylene blue dye

The present study reports on the enhanced photocatalytic and chemocatalytic performance of ZnO/carbon dots (CDs) nanocomposites for the degradation of methylene blue (MB) dye. Carbon quantum dots were prepared by employing Moringa oleifera gum powder as a carbon source through the hydrothermal process. ZnO/CQDs nanocomposites were synthesized by dispersing ZnO nanoparticles into carbon quantum dot solution. The obtained samples were characterized by using techniques like FTIR, UV, and SEM with EDX analysis. When the methylene blue (MB) dye was exposed to visible light at room temperature, the ZnO/CQDs nanocomposites photocatalyst exhibited more photocatalytic and chemocatalytic activity than the pure ZnO nanoparticle photocatalyst. Antibacterial activity and cytotoxic assay of ZnO/CQDs nanocomposites were also investigated. In addition to protecting the environment, the purpose of this research is to create a new visible-light photocatalyst for the effective treatment of organic wastewater.

Plasmon-induced efficient solar-driven H2 production using bimetallic core-shell Cu@Ag:TiO2 nanocomposite photocatalyst

The nano-interface formed by bimetallic Cu@Ag nanoparticles (NPs) on a TiO2 surface enhances charge separation through plasmonic heterojunctions. These bimetallic Cu@Ag NPs were synthesized via the a galvanic replacement reaction (GRR) involving Ag+ in an aqueous medium and metallic Cu NPs on TiO2. During the GRR, Cuδ+ and Agδ+ charge pairs are generated by electron transfer from the catalyst surface. These charge pairs act as active sites, significantly enhancing photocatalytic hydrogen production. Additionally, the cubic crystalline phase of metallic Cu NPs is maintained after the GRR process with Ag ions, while the size of bimetallic Cu@Ag NPs remains constant. Consequently, Cu@Ag NPs supported on TiO2 (Cu@Ag:TiO2) exhibit increased donor charge density of 1.66 × 1020 cm−3 and facilitate rapid charge transfer. As a result, the photocatalytic hydrogen production rate of Cu@Ag:TiO2 is 20 times higher than that of pristine TiO2. Moreover, the visible-light responsive photocatalytic activity of Cu@Ag:TiO2 NPs reaches 3.4 mmol g−1 over 5 hours, which is 78 times higher than that of pristine TiO2. This remarkable enhancement is attributed to the formation of a plasmonic heterojunction with close contact between Cu@Ag and TiO2, enabling efficient charge carrier separation.

Enhanced photocatalytic degradation of Reactive Green 19 dye using earthworms like T-ZnO-CuO nano-composite material as a S-scheme heterojunction photocatalyst

Due to increasing organic dye pollution in the water environment, green and efficient photocatalyst are urgently needed to solve this problem. This study hypothesizes that green-synthesized nanocomposites, using plant leaf extracts, will significantly enhance the efficiency of organic dye degradation without the environmental drawbacks associated with traditional methods. Herein, enhanced degradation of Reactive Green 19 (RG 19) dye using earthworm like T-ZnO-CuO (TZC) nano-composite was reported. T-ZnO (TZ) and TZC nano-composite were synthesized using leaves extract of Thevetia peruviana plant. In the synthesis process, Thevetia peruviana leaves extract acts as a capping, stabilising and reducing agent, and additionally create a unique surface morphology of TZC nano-composite. The establishment of TZ and TZC nano-composite samples were investigated using FT-IR, XRD, FE-SEM with EDX, HR-TEM and UV–VIS DRS spectroscopy. Furthermore, band gap energy of TZ and TZC nano-composites were calculated using Tauc’s plot. The band gap energy of TZC2 nano-composite was determined to be 2.80 eV. The nano-composite photocatalyst (TZC) was utilised in the degradation of RG 19 dye with 96.89 % efficiency in 150 min at 20 mg/L dye concentration, pH=7.5, and 0.6 g/L catalyst dose. In order to investigate the tentative photocatalytic mechanism, scavenging study, recyclability experiment, and stability were also investigated. The findings show that O2− and OH radical species have higher degree of involvement in the degradation process. The kinetics of the degradation of RG 19 dye follows pseudo-first-order kinetics.

Facile construction of ZnWO4/g-C3N4 heterojunction for the improved photocatalytic degradation of MB, RhB and mixed dyes

This study presents the construction of binary ZnWO4/g-C3N4 nanocomposite via a facile hydrothermal approach to enhance the photocatalytic performance under the visible light irradiation. The proposed ZnWO4/g-C3N4 nanocomposite photocatalyst shows excellent photodegradation towards organic dyes, such as methylene blue (MB) and rhodamine B (RhB). The optimal loading of ZnWO4 and g-C3N4 leads to the synergistic effect which plays a predominant role in inhibiting the fast electron-hole pairs recombination rate at the interface of ZnWO4/g-C3N4 photocatalyst. The degradation rates of MB and RhB is achieved around 92.9 % and 88.8 % under the visible light irradiation for 120 min. According to our findings, the radical quenching experiments suggested that the ●OH radicals played a positive impact in the photodegradation process. Since, our proposed photocatalyst exhibit superior photocatalytic activity towards the individual MB and RhB degradation. The ZnWO4/g-C3N4 photocatalyst were further applied to demonstrate the degradation of mixed dyes (MB and RhB) at an irradiation time of 180 min. In the mixed dye solution, the ZnWO4/g-C3N4 photocatalyst achieved a highest reaction rate of 0.010 min−1 for MB and 0.012 min−1 for RhB with the degradation rate of 87.8 % and 83.3 % for RhB and MB, respectively. For the mixed dyes, the radical quenching experiments confirmed that the ●OH radicals are responsible for the fast photodegradation. Additionally, the practicality of the proposed ZnWO4/g-C3N4 photocatalyst towards the degradation of MB, RhB and the mixed dyes were examined in the tap water samples. Furthermore, the plausible photodegradation mechanism of ZnWO4/g-C3N4 photocatalyst was proposed in detail. This study provides a new insight for the simultaneous degradation of mixed chemical pollutants using our proposed ZnWO4/g-C3N4 photocatalyst.

Synthesis of CS/Fe3O4/TiO2@MXene nanocomposite photocatalyst with excellent degradation and bacteriostatic properties by one-step hydrothermal method

With the rapid development of global economy and industrialization, the management and protection of water resources have become increasingly important. In this paper, a novel three-dimensional Chitosan/Fe3O4/TiO2@MXene photocatalyst with excellent degradation and bacterial inhibition properties was prepared by a simple one-step hydrothermal method using FeCl3·6H2O, Chitosan (CS) and MXene (Ti3C2) as main raw materials. TiO2 was generated in-situ on the surface of Ti3C2 nanosheets and modified by loading Fe3O4 nanoparticles and CS films. The conformations and band gaps of the composites were modified, and then photocatalytic mechanisms, phase compositions, morphological structures, magnetic properties and photoelectrochemical properties of the photocatalysts were systematically analyzed. The degradation efficiency of the CS/Fe3O4/TiO2@Ti3C2 composite photocatalyst can reach 95.9 % when the ration of CS to FeCl3·6H2O is 1:3 and the hydrothermal temperature is 180 °C, which showing excellent photocatalytic performance. Meanwhile, the inhibition rate of Staphylococcus aureus (S. aureus) is close to 98.91 % under the light condition. This study further reveals that visible light is a cost-effective way to treat pollution in terms of degradation and bacteriostatic inhibition, and the composite photocatalysts can be efficiently recycled and reused under the action of a magnetic field.

Preparation of Cu/Cu2O/BC and Its Performance in Adsorption-Photocatalytic Degradation of Methyl Orange in Water.

In this study, we prepared a low-cost novel Cu/Cu2O/BC nanocomposite visible-light photocatalyst by the impregnation method using CuSO4·5H2O and rice husk biochar (BC) as raw materials and Na2S2O4 as a single reductant to improve the stability and dispersion of the Cu/Cu2O nanoparticles, in order to solve their aggregation tendency during photocatalysis. The morphology and structure of the Cu/Cu2O/BC were characterized using various analytical and spectroscopic techniques. The photocatalytic effect and cyclic stability of the synthesized photocatalyst on methyl orange (MO) removal were investigated under visible light radiation and various parameter conditions, including the mass ratio of BC to Cu/Cu2O, initial MO concentration, pH, temperature, and catalyst dosage. The results show that the synthesized Cu/Cu2O/BC nanocomposite composed of Cu/Cu2O spherical particles was loaded on the BC carrier, which has better stability and dispersion. The best adsorption-photocatalytic effect of the Cu/Cu2O/BC is exhibited when the mass ratio of BC to Cu/Cu2O is 0.2. A total of 100 mg of Cu/Cu2O/BC can remove 95% of the MO and 88.26% of the COD in the aqueous solution at pH = 6, T = 25 °C, and an initial MO concentration of 100 mg/L. After five cycles of degradation, the MO degradation rate in the sample can still remain at 78.41%. Both the quasi-secondary kinetic model and the Langmuir isothermal adsorption model describe the adsorption process. Additionally, the thermodynamic analysis demonstrates that the photocatalytic process follows the quasi-primary kinetic model and that the removal process is of spontaneous heat absorption. The photocatalyst described in this paper offers a cost-effective, easily prepared, and visible-light-responsive solution for water pollution treatment.

Rational Engineering of Nanostructured NiS/GO/PVA for Efficient Photocatalytic Degradation of Organic Pollutants

A novel nanocomposite film synthesized from an inexpensive and easily accessible polymer such as poly (vinyl alcohol) (PVA), which is coated with nickel sulfide (NiS) and graphene oxide (GO), was obtained from used drinking-water bottles. The produced coated film was examined as a potential photocatalyst film for wastewater treatment promotion in a batch system for the removal of methylene blue (MB) and tetracycline (TC) antibiotics. The experimental results show that the presence of GO significantly increases the photocatalytic efficiency of NiS, and the MB and TC degradation results proved that the incorporation of GO with NiS led to a more than one-and-a-half-fold increase in the removal percentage in comparison with the NiS/PVA-coated film. After 30 min of illumination using GO/NiS/PVA-coated film, the removal efficiency reached 86% for MB and 64% for TC. The photodegradation kinetic rate followed the pseudo-first-order rate. Furthermore, the response surface methodology (RSM) model was utilized to study and optimize several operating parameters. The ideal circumstances to achieve 91% elimination of MB are 12 mg L−1 MB initial concentration, two lamps, and an illumination time of 15 min; however, to achieve 85% TC removal, 11 mg L−1 TC initial concentration, two lamps, and a 45 min illumination time should be used. The fabricated nanocomposite photocatalyst film seems to have promise for use in water purification systems.

Modeling sustainable photocatalytic degradation of acidic dyes using Jordanian nano-Kaolin–TiO2 and solar energy: Synergetic mechanistic insights

The abstract highlights the global issue of environmental contamination caused by organic compounds and the exploration of various methods for its resolution. One such approach involves the utilization of titanium dioxide (TiO2) as a photocatalyst in conjunction with natural adsorption materials like kaolin. The study employed a modeling-based approach to investigate the sustainable photocatalytic degradation of acidic dyes using a Jordanian nano-kaolin–TiO2 composite material and solar energy. Mechanistic insights were gained through the identification of the dominant reactive oxygen species (ROS) involved in the degradation process, as well as the synergetic effect between adsorption and photocatalysis. The Jordanian nano-kaolin–TiO2 composite was synthesized using the sol-gel method and characterized. The nanocomposite photocatalyst exhibited particle sizes ranging from 27 to 41 nm, with the TiO2 nanoparticles well-dispersed within the kaolin matrix. The efficacy of this nanocomposite in removing Congo-red dye was investigated under various conditions, including pH, initial dye concentration, and photocatalyst amount. The optimal conditions for dye removal were found to be at pH 5, with an initial dye concentration of 20 ppm, and using 0.1 g of photocatalyst, resulting in a 95 % removal efficiency. The mechanistic insights gained from this study indicate that the hydroxyl radicals (•OH) generated during the photocatalytic process play a dominant role in the degradation of the acidic dye. Furthermore, the synergetic effect between the adsorption of the dye molecules onto the photocatalyst surface and the subsequent photocatalytic degradation by the ROS was found to enhance the overall removal efficiency. These findings contribute to the fundamental understanding of the photodegradation mechanisms and guide the development of more efficient photocatalytic systems for the treatment of acidic dye-containing wastewater. The use of solar power during the purification procedure also leads to cost reduction and strengthens sustainability efforts.

BiVO4/sulfur-doped g-C3N4 nanocomposite as photocatalyst for degradation of ciprofloxacin under visible light irradiation

In recent years, the use of antibiotics has greatly increased, which has caused environmental pollution. We offer a photocatalyst based on BiVO4/sulfur-doped g-C3N4 nanocomposite, which was made by a one-step thermal condensation method from thiourea and bismuth vanadate to degradate ciprofloxacin (CIP). The BiVO4/sulfur-doped g-C3N4 photocatalyst was analyzed by certain techniques including XRD, FTIR, BET, FESEM, EDX, TEM, DRS, photoluminesence, and Mott-Schottky to determine various physicochemical properties. The photocatalytic degradation of CIP, as a model pollutant, under visible LED light irradiation was tested to investigate the catalytic performance of nanocomposite. Response Surface Methodology (RSM) was employed to optimize operational parameters, including photocatalyst dosage (50–150 mg), CIP concentration (10–30 mg/L), initial pH of the solution (3–11), and irradiation time (12–120 min). The BiVO4/sulfur-doped g-C3N4 nanocomposite, with a narrow bandgap of 2.15 eV, exhibited exceptional photocatalytic performance in degrading CIP. The optimal conditions for CIP removal were photocatalyst dosage of 120.9 mg, CIP concentration of 10 mg/L, and initial solution pH of 3, resulting in 93.5 % removal efficiency after 105 min of irradiation. The photocatalytic degradation kinetics of CIP followed a pseudo-first-order model with a rate constant (K) of −0.0221 L/min, indicating rapid degradation process. The photocatalyst maintained excellent performance after 5 reuses, with only a 3 % reduction in efficiency. XRD analysis confirmed the structural stability of the nanocomposite after reuse.

Sustainable Wastewater Treatment with Bi2MoO6/Cellulose Acetate Photocatalytic Membranes

AbstractA major challenge for modern society is securing quality water for various uses. Membrane water treatment will be crucial for drinking water, desalination, and wastewater reuse. The development of bismuth molybdate (Bi2MoO6) nanoparticles has enabled the production of novel Bi2MoO6‐incorporated cellulose acetate (CA) membrane nanocomposite. The synthesized Bi2MoO6/CA nanocomposites are thoroughly examined for their structural, morphological, and photocatalytic characteristics using X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) with energy dispersive X‐ray spectroscopy (EDX) analysis. The photocatalytic properties are determined by evaluating the degradation of Malachite Green (MG) and Rose Bengal (RB) by the nanocomposite membranes under the illumination of a UV light simulator. Notably, the Bi2MoO6/CA nanocomposite membrane displays exceptional and sustained photocatalytic efficiency (78%) and (84%) in MG and RB dye degradation, respectively. Moreover, the effective loading of the Bi2MoO6 onto the CA membrane enhances electron and hole adsorption while facilitating carrier movement. Furthermore, the stability exhibited by the Bi2MoO6/CA nanocomposite photocatalysts remains impressive even after multiple cycles, demonstrating their durability. This research introduces a cutting‐edge semiconductor‐based hybrid nanocomposite material that proves highly efficient in the photocatalytic degradation of organic dyes, showcasing promising advancements in environmental remediation strategies.

Hydrothermal synthesis of cadmium sulfide decorated reduced graphene oxide photocatalyst for the degradation of photostable naphthol blue black dye

Photocatalysis is being used for the mineralization of recalcitrant organic pollutants in water that cannot be treated with conventional methods. Cadmium sulfide decorated reduced graphene oxide (rGO-CdS) nanocomposite photocatalyst was synthesized by hydrothermal method and evaluated for the removal of a photostable textile azo dye, naphthol blue black (NBB) under ultraviolet light (UV-A, 365 nm). The rGO-CdS combination was opted for due to utilizing the narrow band gap (Eg = ~2.4 eV) of CdS and robust rGO support, capable of attracting organic pollutants to surface, bear, and protect CdS from photocorrosion. The formation of rGO-CdS was proved from the findings of physiochemical characterization UV–visible-, X-ray diffraction photoelectron, Raman, energy dispersive X-ray-spectroscopic, and scanning, transmission electron, and atomic force microscopic studies. The spherical CdS was decorated on the random shaped rGO sheets. Eg of CdS and rGO-CdS were 2.42 and 2.39 eV, respectively. After 2 h of light exposure, 2 g/L of rGO-CdS mineralized 95 % of NBB (2 × 10−4 mol/L). After 5 cycles, 80 % of photocatalytic efficiency was retained. In gas chromatography-mass spectrometry studies, 8 fragments of NBB were found after 1 h and confirmed that the degradation was mediated by photocatalytic dilapidation. The optimum pH for NBB degradation was 9. The rGO-CdS was found to be a potentially stable and reusable photocatalyst for environmental applications.

Novel S-scheme β-Cu2V2O7/Ni/Pg-C3N4 heterojunction photocatalyst for sunlight-induced degradation of RhB

A novel S-scheme β-Cu2V2O7/Ni/Pg-C3N4 nanocomposite photocatalyst has been advantageously established by propelling β-Cu2V2O7 nanoparticles (NPs) on the top layer of porous graphitic carbon nitride (Pg-C3N4) nanosheets (NSs) using a facile co-precipitation approach. Implementing photoelectrochemical and physicochemical techniques, the crystallinity, purity, optical quality, morphology, chemical composition, and charge separation efficiency of the produced samples were examined. The outcomes indicate that metallic Ni and β-Cu2V2O7 NPs were perfectly encapsulated onto the Pg-C3N4 NSs and well-matched band structures between both semiconductors facilitate the creation of an S-scheme charge transfer path. The fabricated pristine and β-Cu2V2O7/Ni/Pg-C3N4 composite samples were utilized as a catalyst for the removal of rhodamine B (RhB) dye under sunlight irradiation. The β-Cu2V2O7/Ni/Pg-C3N4 nanocomposite exhibits exceptional activity within 60 min of radiation exposure (RhB- 98.56%), whereas β-Cu2V2O7 and Pg-C3N4 show reduced activity (RhB-34.4% and 45.68%). The favourable impact of S-scheme nanocomposite establishment boosted photocatalytic behavior using the intrinsic electric field among Pg-C3N4 NSs and β-Cu2V2O7 and surface plasmon resonance (SPR) effect of metallic Nickel (Ni) NPs for delivering e− and h+ pairs and prolonging the life of charge carriers. According to radical scavenging experiments •O2− is the primary reactive species followed by •OH radicals. The produced nanocomposite has the potential to be employed in large-scale photocatalytic water treatment, as evidenced by the photocatalyst's excellent efficiency and reusability after five consecutive experiments.