Visible Light Photocatalytic Degradation Research Articles

Binary Ce-doped-ZnO/rGO composite as excellent photocatalyst for bromothymol blue dye degradation

Organic contaminants pose a grave danger to both the surroundings and public health, which emphasizes the urgent need for efficient decomposition techniques. Building a composite and adding a cocatalyst can both enhance the transfer of photogenerated electrons, which are useful strategies to increase photocatalytic efficiency. This study sought to synthesize cerium–doped ZnO–rGO nanoparticles with varying concentrations of Ce for visible–light photocatalytic degradation of bromothymol blue dye in water. The synthesized photocatalysts were characterized using transmission electron microscopy, x–ray diffraction, ultraviolet–visible spectrophotometry, energy dispersive spectroscopy, and scanning electron microscopy. The results disclosed that the photoactivity of the 0.6% Ce–ZnO–rGO was the highest and degraded 92% of bromothymol blue dye under visible light within 180 min (k = 1.072 ×10–2 min–1) compared to the pristine ZnO which only degraded the dye by about 22% (k = 1.15 ×10−3 min−1). The band gap of the pure ZnO was estimated to be 3.09 eV and that of the best performing composite (0.6% Ce) to be 2.81 eV which we suggest are responsible for the improved photodegradation. The pseudo–first–order photocatalytic kinetic has a strong correlation value of 0.99. The Ce–ZnO–rGO composites offer a lot of potential for cleaning the environment.

Ferrocenylselenoether and its cuprous cluster modified TiO2 as visible-light photocatalyst for the synergistic transformation of N-cyclic organics and Cr(vi).

In this study, fcSe@TiO2 and [Cu2I2(fcSe)2]n@TiO2 nanosystems based on ferrocenylselenoether and its cuprous cluster were developed and characterized by X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray spectroscopy (EDX), and electron paramagnetic resonance (EPR). Under optimized conditions, 0.2 g L-1 catalyst, 20 mM H2O2, and initial pH 7, good synergistic visible light photocatalytic tetracycline degradation and Cr(vi) reduction were achieved, with 92.1% of tetracycline and 64.5% of Cr(vi) removal efficiency within 30 minutes. Mechanistic studies revealed that the reactive species ˙OH, ˙O2-, and h+ were produced in both systems through the mutual promotion of Fenton reactions and photogenerated charge separation. The [Cu2I2(fcSe)2]n@TiO2 system additionally produced 1O2 from Cu+ and ˙O2-. The advantages of the developed nanosystems include an acidic surface microenvironment provided by Se⋯H+, resourceful product formation, tolerance of complex environments, and excellent adaptability in refractory N-cyclic organics.

Enhanced visible-light photocatalytic degradation of organic pollutants using fibrous silica titania and Ti3AlC2 catalysts for sustainable wastewater treatment

Visible light photocatalysis offers a green and sustainable approach to wastewater treatment and environmental remediation.

Eco-benign synthesis of α-Fe2O3 mediated Trachyspermum ammi: A new insight to photocatalytic and bio-medical applications

Environmental contaminants are a golabl concern, and even at very low quantities, they can be extremely harmful to the aquatic ecosystem. Microbial resistance and photocatalysis are popular strategies for removing hazardous substances from the environment. The present study developed the green synthesis of α-Fe2O3 nanoparticles from Trachyspermum ammi plant leaf extract. The crystalline and structural stability of green synthesized α-Fe2O3 nanoparticles were studied by XRD. The surface morphology was investigated by TEM and FESEM equipped with EDX analysis. Metal, oxygen bond (Fe-O) and their interaction on the surfaces and their valency were explored from FTIR and XPS spectra. Optical orientations and electron movements were revealed from UV-DRS analysis. Visible light photocatalytic methylene blue degradation confirmed the largest surface area, rate of recombination, photo-excited charge carriers, photo-sensitivity range and radical generations of α-Fe2O3 nanoparticles. The green synthesized α-Fe2O3 nanoparticles bacterial susceptibility was examined by the well diffusion method using (10, 20, 50, 100) µg/L concentration of nanoparticles. The antibacterial activity enhanced with the higher concentration of α-Fe2O3 (100 µg/L). The gram-negative bacteria of E.coli has high bacterial susceptibility on α-Fe2O3 nanoparticles. The reactive oxygen species and OH radicals of α-Fe2O3 nanoparticles are demonstrated better resistivity against bacterial strains. The present study, therefore, suggested that the green synthesis would be an appropriate approach to synthesize the nanomaterials and confirming their suitability for use in industrial wastewater treatment and biomedical applications.

Novel MgO and Ag/MgO nanoparticles green-synthesis for antibacterial and photocatalytic applications: A kinetics-mechanism & recyclability

The present study identifies the novel nano production of MgO nanoparticles as well as the Ag decoration of MgO nanoparticles using Morinda tinctoria plant extract. Green compounds are used to reduce zero valent atoms and to decorate metal oxide surfaces. X-ray Diffractometer analysis (XRD) was used to examine the cubic structure of MgO (28 nm) and Ag/MgO (21 nm) nanoparticles. Fourier transform infrared spectroscopy (FTIR) analysis was used to determine the reactive functional groups, metal–oxygen bonding, and OH molecules. Ultra-Violet Diffuse Reflectance Spectroscopy (UV-DRS) analysis revealed the optical entity and their orbital electron shift. Using the Kubelka-Munk relation, the optical defect of MgO (4.68 eV) and Ag/MgO (3.18 eV) nanoparticles was calculated. Scanning Electron Microscope (SEM) indicated surface decorations and their pure MgO nanoparticles rod-like shape, and Energy-Dispersive X-Ray Spectroscopy (EDX) identified their elements. TEM analysis confirmed the poly-dispersive nature of the Ag decorations on the MgO surface. X-Ray Photoelectron Spectroscopy (XPS) was used to determine the valency of metal (Ag-3d) and metal oxide (Mg-2 s&O-1 s). MgO and Ag/MgO were used in visible light photocatalytic dye degradation of Rh-B dye. The biological properties were tested against S.aureus and E.coli. The plasmonic decoration on the MgO surface accelerated photodegradation and increased biological susceptibility. The innovative characteristics of this work squeeze the green synthesis of Ag/MgO nanoparticles, their improved photocatalytic and antibacterial performance, and their potential applications in water remediation and biomedicine.

Rapid photocatalytic degradation of organic pollutants by Al3+ doped CuO powders under low power visible light and natural sunlight

The photocatalytic degradation of organic pollutants is a promising approach to deal with dye industry wastes released into water bodies. However rapid, inexpensive, and low power visible light photocatalytic degradation of water pollutants is challenging. This study tries to address these constraints by using inexpensive doped CuO Powders under low-power visible household LED light. Also, direct illumination of sunlight to achieve better photocatalytic degradation, reducing device and operational costs. Further, photocatalytic degradation is enhanced by doping of Al3+ in CuO. Under several optimized conditions, rapid and almost complete degradation of three different dyes, Methylene Blue (MB), Rhodamine B (RhB), and Methyl Orange (MO) were achieved within 6 min of light irradiation under household LED and within 30 min of direct irradiation of sunlight. Even after five times of repeated use of the catalyst, no significant decrease in the photocatalytic activity was observed indicating its stability and sustainability.

Visible-light photocatalytic degradation of two textile dyes by recyclable ZnO-Perlite: kinetic models and cost analysis

ABSTRACT Zinc oxide (ZnO), as an n-type semiconductor photocatalyst, is often selected due to its excellent photocatalytic performance and is supported on commercial expanded perlite (EP) to enhance interfacial charge separation efficiency under visible LED light. The structure and photocatalytic properties of the synthesised photocatalyst via the co-precipitation route were studied through XRD, FT-IR, SEM, EDX and pHpzc analyses. The photocatalytic response was evaluated by studying the degradation of two toxic and refractory azo dyes, reactive black 5 (RB5) and acid red 14 (AR14). Azo dyes (20 mg L−1) were completely degraded in the studied system, which occurred at pH 7 and 3, with catalyst amounts of 2 and 1 g L−1, and in the presence of H2O2 at 2 and 10 mM under LED light (15 W) within 2 h for RB5 and AR14, respectively. The degradation of RB5 and AR14 followed first-order kinetics with Kobs values of 0.0218 and 0.0169 min−1 and R2 values of 0.9271 and 0.8325, respectively. The assessment of energy consumption (EEO) and total operation cost (OC) confirmed that the supported ZnO offered the lowest power and cost requirements to transform selected pollutants into the acquired effluent, with values of 20.65 and 25.13 kWh m−3 and 3.11 and 3.205 USD kg−1 for RB5 and AR14, respectively, compared to using only VIS/ZnO, VIS/EP and VIS. Furthermore, the catalyst exhibited stability without the need for any additional chemicals for up to 10 h (5 reuse cycles). Additionally, the presence of major anions (sulphate, chloride and alkalinity) reduced the degradation efficiency in a real water matrix (1.74 and 1.47 times for RB5 and AR14, respectively) compared to that in distilled water.

Construction of Embedded Sulfur-Doped g-C3N4/BiOBr S-Scheme Heterojunction for Highly Efficient Visible Light Photocatalytic Degradation of Organic Compound Rhodamine B.

Constructing S-scheme heterojunction catalysts is a key challenge in visible-light catalysed degradation of organic pollutants. Most heterojunction materials are reported to face significant obstacles in the separation of photogenerated electron-hole pairs owing to differences in the material size and energy barriers. In this study, sulfur-doped g-C3N4 oxidative-type semiconductor materials are synthesized and then coupled with BiOBr reductive-type semiconductor to form S-g-C3N4/BiOBr S-scheme heterojunction. A strong and efficient internal electric field is established between the two materials, facilitating the separation of photogenerated electron-hole pairs. Notably,in situ XPS proved that after visible light irradiation, Bi3+ is converted into Bi(3+ɑ)+, and a large number of photogenerated holes are produced on the surface of BiOBr, which oxidized and activated H2O into •OH. •OH cooperated with •O2 - and 1O2 to attack Rhodamine B (RhB) molecules to achieve deep oxidation mineralization. The composite material is designed with a LUMO energy level higher than that of RhB, promoting the sensitization of RhB by injecting photogenerated electrons into the heterojunction, thereby enhancing the photocatalytic performance to 22.44 times that of pure g-C3N4. This study provides a new perspective on the efficient degradation of organic molecules using visible light catalysis.

Visible light photocatalytic degradation of dyes by Ag3PO4/g-C3N4/CQDs composite

To facilitate the realize high-value utilization of coal tar pitch, carbon quantum dots (CQDs) were synthesized using ball-milling-assisted H₂O₂ oxidation method with tar pitch as carbon source. Subsequently, Ag₃PO₄/g-C₃N₄/CQDs composites were prepared through the electrostatic self-attraction of CQDs, Ag₃PO₄ and g-C₃N₄. These composites were then employed for the photocatalytic degradation of dyes, including methyl orange (MO), methylene blue (MB) and rhodamine B (RhB). A case study of MO, the degradation rate constant of Ag₃PO₄/g-C₃N₄/CQDs reached 0.02469 min−1, which was 11 times and 1.6 times higher than that of g-C₃N₄ and Ag₃PO₄. It found that Ag₃PO₄:g-C₃N₄ mass ratio of 1:1 and 5 mg/L CQDs solution loading were optimal. Characterization analysis revealed the specific surface area of the catalyst was increased and optimized band gap structure after the combination of CQDs as the co-catalyst. The possible reaction mechanism was also expounded, Ag₃PO₄/g-C₃N₄/CQDs constructed Z-scheme heterostructure, with CQDs as electron bridge. In addition, the impact of catalyst mass, initial concentration, and pH on the degradation process was studied, as well as the cyclic stability of the catalyst. Based on capture and ESR tests, the main active substances involved in the reaction were in the following order: h+ > ·OH > ·O2−. These experiments provided a new idea on the application of coal-based CQDs in the field of visible light catalytic degradation.

Hydrothermal synthesis of Bi2WO6/Bi2O4 heterojunction with WO3 and NaBiO3·2 H2O powders as precursors to improve visible light photocatalytic degradation performance

The limited visible light response range and fast recombination rate of photoinduced carriers restrict the photocatalytic performance of Bi2WO6. Herein, a novel low temperature hydrothermal approach was developed to construct the Bi2WO6/Bi2O4 heterojunction with WO3 and NaBiO3•2 H2O powders as precursors and the latter as the only bismuth source. During the hydrothermal reaction, WO3 first reacts with NaBiO3·2 H2O to generate Bi2WO6 and then the residual NaBiO3·2 H2O converts into Bi2O4, in-situ forming the Bi2WO6/Bi2O4 heterojunction with the co-shared Bi atoms. The content of Bi2WO6 in the heterostructure can be facilely modulated by changing the amount of WO3 added. The construction of Bi2WO6/Bi2O4 heterojunction could not only extend the spectral response range but also improve the separation efficiency of photoinduced charges. Consequently, the photocatalytic degradation performance to tetracycline (phenol) for the optimal Bi2WO6/Bi2O4 heterostructure is 5.19 and 1.77 times (4.75 and 1.66 times) higher than that of single Bi2WO6 and Bi2O4 under visible light, respectively. The capture experiments of active species and electron spin resonance spectra demonstrate that radicals (·O2-) and holes (h+) are the first and second important active species, respectively, during the catalytic degradation. Our work provides a new idea for the fabrication of high-performance Bi2WO6-based junction photocatalysts.

Synergistic interface engineering in n-p-n type heterojunction Co3O4/MIL/Mn-STO with dual S-scheme multi-charge migration to enhance visible-light photocatalytic degradation of antibiotics

Constructing an effective multi-heterojunction photocatalyst with maximum charge carrier separation remains challenging. Herein, a high-efficient Co3O4/MIL-88A/Mn–SrTiO3 (Co3O4/MIL/Mn-STO) n-p-n heterojunction photocatalyst was successfully prepared by a simple hydrothermal method for the photodegradation of sulfamethoxazole (SMX). The combination of MIL and Co3O4/Mn-STO established an internal electric field and heterojunction, accelerating the separation of carriers, and thus improved photocatalytic performance. In the Co3O4/MIL/Mn-STO photocatalytic system, 95.5 % of SMX was degraded in 90 min. The photocatalytic kinetic removal rate of Co3O4/MIL/Mn-STO reached 0.0337 min−1, 8 times of Co3O4 (0.0041 min−1), 5.2 times of Mn-STO (0.0062 min−1), 4.6 times of MIL (0.0078 min−1), and 3.6 times of MIL/Mn-STO (0.0095 min−1). Remarkably, superoxide radicals (•O2−) and holes (h+) have been recognized as the main active species in the degradation process through reactive species elimination experiments and electron spin resonance (ESR) tests. The experimental and theoretical proved the in-built interfacial contact and synergistic effect between the photocatalyst accomplished with low bandgaps, high specific surface area, more reaction sites, high electron-hole pair separation, and maximum solar-light utilization. The molecular structure and possible degradation routes with intermediate products in the photocatalytic system were investigated using a liquid chromatography-mass spectrometer (LC-MS) and DFT calculations. This work provided new insight into the guidelines of rational design/growth of new multicomponent photocatalysts to remove antibiotics and other emerging contaminants in wastewater.

Visible light photocatalytic degradation of methylene blue and rhodamine B over silver-doped titanium dioxide nanocomposites supported on Fuller's earth.

Silver-doped-titanium dioxide nanoparticles supported on Fuller's earth, prepared by the sol-gel method, were characterized with XRD, TGA, zeta potential, SEM, EDX, TEM, XPS, photoluminescence and UV-DRS measurements. The material, Ag-TiO2-Fuller's earth (AgTF), was tested for photocatalytic activity concerning the degradation of rhodamine B (RhB) and methylene blue (MB) in aqueous solution under visible light irradiation with pH, catalyst dosage, and dye concentration as the process variables. The degradation kinetics indicated pseudo-first-order kinetics with rate constant of (i) 0.55 min-1with 0.12 gL-1AgTF loading, 10-5 M MB at pH 9, and (ii) 0.53 min-1 with 0.08 g L-1 AgTF loading, 5 × 10-5 M RhB at pH 8. The methylene blue degradation was maximum (98.66%) for AgTF loading of 0.12 g L-1 while the maximum RhB degradation (96.34%) was attained with AgTF loading of 0.08 g L-1. With 5 × 10-6M MB concentration, the degradation achieved was 98% in 45 min and 100% in 60 min. One hundred per cent degradation of the dye, RhB (1 × 10-6 M) could be achieved in 30 min with 0.08 g L-1 AgTF at pH 8. The use of Fuller's earth, a cheap, abundant and large surface area support, increases the adsorbability of the dye on the catalyst surface and hence promotes the degradation. The catalyst could be removed easily from the reaction mixture and reused for up to five cycles without any significant decrease in activity. Scavengers such as triethanolamine (TEOA), p-benzoquinone (BQ) and isopropyl alcohol (IPA) were utilized to get some insight into the photocatalysis mechanism.

Facile synthesis of novel CoWO4/FeWO4 hetrocomposite with efficient visible light photocatalytic degradation and hydrogen evolution aspects

ABSTRACT Tungstate-based nanomaterials exhibit efficient photocatalytic performance and offer several advantages owing to their electrical and superior optical features, charge transport potentials, and superb corrosion resistance. The objective of the present study is to fabricate cobalt tungstate (CoWO4), Ferric tungstate (FeWO4) and CoWO4/FeWO4 heterojunction composite photocatalysts using a hydrothermal route with various molar concentrations (2:1, 1:1, 1:2, 1:5). The model pollutant Methyl Orange (MO) and Congo Red (CR) azo dyes were degraded 98.26% and 99.61% in 150 min by the as-synthesized CoWO4/FeWO4 at a molar concentration ratio of 1:2. A feasible photodegradation mechanism is purposed and the optimum values for different parameters are also evaluated by considering two different dyes as model organic pollutants. Hydrogen production efficiency reaches up to 36 μmolg−1 h−1 under visible light over 1:2 CoWO4/FeWO4. This work may open new possibilities for the use of CoWO4/FeWO4 composite for potential applications such as the hydrothermal synthesis of composites and their photocatalytic wastewater remedy and as hydrogen evolution applications.

A Novel Synthetic 3D Interconnected Porous Carbon-Rich Graphitic Carbon Nitride for Boosting Visible Light Photocatalytic Hydrogen Production and Dye Contaminant Degradation

The use of photocatalysis to address environmental pollution and energy shortage is an attractive choice. Herein, we successfully synthesized a novel 3D interconnected porous carbon-rich g-C3N4 catalyst via facile thermal polymerization to enhance photocatalytic hydrogen production and photodegradation of dye contaminants. Enhanced hydrogen evolution (1956.23 μmol g−1 h−1) and photocatalytic RhB degradation (96.74%) efficiency were achieved with the as-obtained catalysts. Based on the photocatalytic experimental data and characterization analyses, an enhancement mechanism was proposed. The 3D interconnected porous structure endowed the g-C3N4 with numerous active sites and a large specific surface area, and the carbon modification facilitated the separation and transfer of the photoinduced charge carriers. Nanoshape engineering and the carbon-rich structure showed a synergetic effect in increasing photocatalytic performance. This study offers an applicable methodology for the exploitation of an economical catalyst to alleviate environmental pollution and energy shortages.

Energy band matching Bi2WO6/black-TiO2 Z-scheme heterostructure for the enhanced visible-light photocatalytic degradation of toluene

By exploiting the distinct band alignment characteristics of various semiconductors, the Z-scheme heterostructure represents a significant method to improve the effectiveness of energy conversion processes. In this work, Bi2WO6/Black-TiO2 (BTB) compounds are developed using the hydrothermal method combined with sol-gel method. It is shown that the separation efficiency of photoinduced carriers on BTB is visibly raised via establishing a Z-scheme system with matched energy band structures. The surface carrier separation efficiency is closely related to photocatalytic activity. Under visible light, the degrading performance of toluene over BTB heterostructure is found to be markedly enhanced. BTB-3 exhibits the optimal photocatalytic activity of the group, achieving a toluene conversion of 90% after 120 min reaction, which is twice and 5.5 times larger than that of B-TiO2 and Bi2WO6, respectively. Furthermore, developing of BTB Z-scheme heterostructure can preserve the catalyst's initial redox capacity, thereby producing more significant active species, e.g., ·OH and ·O2−radicals, to efficiently decompose toluene. According to in-situ DRIFTS data, acids, aldehydes and alcohols are among the intermediates that are collected during various stages of toluene's photocatalytic breakdown. This work supplies a fresh, workable route for future photocatalytic volatile organic compounds degradation.

Localized surface plasmon resonance enhanced charge transfer effect in MoO2/ZnSe nanocomposites enabling efficient SERS detection and visible light photocatalytic degradation

The detection of pharmaceutical residues in the environment based on surface enhanced Raman spectroscopy (SERS) technology has become a popular tool due to its superior molecular specificity and high sensitivity. However, the practical applicability of semiconductor-based SERS sensors for trace pharmaceutical contaminants is limited due to their weak and unstable SERS performance. Herein, a donor-bridge-acceptor (D-B-A) system of MoO2 and ZnSe was fabricated to enhance the separation efficiency of electron-hole pairs in ZnSe and the charge transfer between MoO2 and ZnSe, which causes the MoO2/ZnSe nanocomposites to exhibit excellent SERS sensitivity and photocatalytic activity for the detection of multi-component contaminants and the antibiotic. The LOD of ciprofloxacin hydrochloride (CIP HCl) on MoO2/ZnSe nanocomposites is 8.30 × 10−8 M, and the degradation rate of CIP HCl is 80 % after visible light irradiation for 180 min. Our research effectively improves the SERS sensitivities and expands the practical SERS application of plasma-nonmetal/semiconductor composites, and avoids secondary contamination in the detection process. The enhancement mechanism of SERS and the interpretation of photocatalytic phenomena provide promising guidance for providing a low-cost and stable composite SERS platform in the detection and treatment of emerging contaminants.

Sulfur vacancies promoted highly efficient visible light photocatalytic degradation of antibiotic and phenolic pollutants over WS2/rGO heterostructure

Antibiotic and phenolic contaminations are severe and have become a significant source of worry in recent years. A multifunctional sulfur vacancy-induced WS2/rGO heterostructure was fabricated by a simple hydrothermal process for the photocatalytic degradation of antibiotic and phenolic compounds. The sulfur-based defects can reduce bandgap energies and enhance visible light absorption. The sulfur-enriched WS2/rGO heterostructure exhibited efficient photocatalytic activity towards Ciprofloxacin (CIP) and 4-Nitrophenol (4-NP) degradation under visible light illumination, and the deceptive rate constant is about 13 and 22 times higher than pristine WS2, and the removal efficiency was 16 and 13 times higher than pristine GO catalysts. The degradation efficiency and kinetic rate constants of 4-NP and CIP were 96.95 %, 92.30 %, and 0.113 min−1, 0.027 min−1, respectively. The excellent photocatalytic activity of WS2/rGO heterostructure was due to rGO acts as an electron mediator, and helps to accelerate charge separation and reduce the recombination rates. In addition, rGO improved the surface appearance of the heterostructure and provided more adsorption and reaction sites. The photocurrent measurement and time-resolved spectrum were used to investigate the photogenerated charge separation. Furthermore, the superoxide radical was the dominant reactive species of 4-NP and CIP degradation, as demonstrated by electron spin resonance and scavenger experiments. The possible degradation pathway and mechanism of 4-NP were proposed using liquid chromatography-mass spectroscopy.

Sonochemically prepared bismuth doped titanium oxide-reduced graphene oxide (Bi@TiO2-rGO) nanocomposites for effective visible light photocatalytic degradation of malachite green

In the present work, rGO (reduced graphene oxide) was used as a support material for the preparation of Bi@TiO2-rGO nanocomposites with uniform morphology with using ultrasound assisted process. Bi@TiO2-rGO nanocomposites samples at various loading of Bi were prepared by a facile sol-gel method assisted by ultrasound waves and their performance was compared with nanocomposites prepared by conventional stirring method. Formation of Bi and Ti based nanoparticles supported with rGO sheet was confirmed by scanning electron microscopy. The successful incorporation of rGO, Bi and Ti in Bi@TiO2-rGO nanocomposites was confirmed by XRD, Raman spectroscopy and EDAX. The XRD study showed phases corresponding to Bi, Ti and rGO and indicated the formation of crystalline Bi@TiO2-rGO nanocomposite. From the morphological analysis of nanocomposites, uniformly decorated layered morphology was observed. XRD and Raman analyses confirmed the presence of Bi, Ti and formation of rGO during preparation of Bi@TiO2-rGO nanocomposite using ultrasound assisted and conventional method. Prepared Bi@TiO2-rGO nanocomposite was applied for the degradation of malachite green dye. The photocatalytic degradation experiments were carried out in sunlight using Bi@TiO2-rGO nanocomposites prepared with varied loading of Bi using ultrasound and conventional method. At the optimum condition, degradation was found to be 93.34 % in sunlight.

Congregating Ag into γ-Bi2O3 coupled with CoFe2O4 for enhanced visible light photocatalytic degradation of ciprofloxacin, Cr(VI) reduction and genotoxicity studies

The work attempts to construct a highly effective γ-Bi2O3/CoFe2O4/Ag visible active photocatalyst for the enhanced degradation of ciprofloxacin (CIP) and Cr(VI) reduction. γ-Bi2O3/CoFe2O4/Ag photocatalyst was prepared by simple solid phase and co-precipitation methods. The nanosphere shaped CoFe2O4 photocatalyst are embedded on top of γ-Bi2O3 nanotriangle. The addition of Ag into γ-Bi2O3/CoFe2O4 heterojunction primitively facilitates the photocatalytic activity in higher rate. The quantitative analysis of photocatalyst possesses to have lower e−/h+ recombination rate compared to its counterparts. The prepared γ-Bi2O3/CoFe2O4/Ag photocatalyst showed 96.6% degradation of CIP in 220 min and 99.2% reduction of Cr(VI) in 120 min. Additionally, γ-Bi2O3/CoFe2O4/Ag showed outstanding recyclability and long-term stability with a degradation efficiency of 96.5% even after six cycles. The intermediate products formed were identified and the degradation pathway was elucidated by gas chromatography-mass spectrometry analysis. Total organic carbon measurement was carried over to assess the efficiency of complete degradation and the removal percentage was found to be 98%. The end product toxicity study towards bacteria was proven to have less toxicity level when compared to parent compound. Lastly, the genotoxicity of γ-Bi2O3/CoFe2O4/Ag photocatalyst was tested in Allium cepa and the results confirmed to have no cause of toxicity impacts. Overall, the work not only tends to provide a highly visible active γ-Bi2O3/CoFe2O4/Ag photocatalyst, but also attributes to have no further negative imprints in the environment.

Preparation, Characterization, and Application of Novel Ternary PPS/PVA/Fe3O4 Nanocomposite for Enhanced Visible Light Photocatalytic Degradation of Methylene Blue

Preparation, Characterization, and Application of Novel Ternary PPS/PVA/Fe3O4 Nanocomposite for Enhanced Visible Light Photocatalytic Degradation of Methylene Blue