Photodegradation Of Rhodamine B Research Articles

Ag3PO4/g-C3N4/Zn3(PO4)2 catalyst with ternary heterostructure and Z-scheme/type Ⅱ dual pathway mechanism for high photocatalytic performance

A novel Ag3PO4/g-C3N4/Zn3(PO4)2 photocatalyst with ternary heterostructure and Z-scheme/type Ⅱ dual pathway mechanism was synthesized. Scanning electron microscopy and transmission electron microscopy data showed that Ag3PO4, Zn3(PO4)2, and g-C3N4 were in close contact, leading to the formation of the ternary heterojunction. Under simulated solar light irradiation, the Ag3PO4/g-C3N4/Zn3(PO4)2 photocatalyst efficiently degraded rhodamine B (RhB) and displayed much higher photocatalytic activity than pure Ag3PO4, g-C3N4, Zn3(PO4)2, and Ag3PO4/Zn3(PO4)2 composite, exhibiting a RhB photodegradation efficiency of ∼91.2 % within 60 min. The quenching effects of different scavengers and electron spin resonance (ESR) experiments demonstrated that reactive h+ and·O2− species played major roles in the photocatalytic reaction. It was elucidated that excellent photocatalytic activity could be ascribed to the Z-scheme/type Ⅱ dual carrier transfer pathways. Therefore, the formation of a ternary heterostructure system is an efficient method for separating charge carriers and retaining their redox capabilities.

Ba3(PO4)2 Photocatalyst for Efficient Photocatalytic Application.

Barium phosphate (Ba3(PO4)2) is a class of material that has attracted significant attention thanks to its chemical stability and versatility. However, the use of Ba3(PO4)2 as a photocatalyst is scarcely reported, and its use as a photocatalyst has yet to be reported. Herein, Ba3(PO4)2 nanoflakes synthesis is optimized using sol-gel and hydrothermal methods. The as-prepared Ba3(PO4)2 powders are investigated using physicochemical characterizations, including XRD, SEM, EDX, FTIR, DRS, J-t, LSV, Mott-Schottky, and EIS. In addition, DFT calculations are performed to investigate the band structure. The oxidation capability of the photocatalysts is investigated depending on the synthesis method using rhodamine B (RhB) as a pollutant model. Both Ba3(PO4)2 samples prepared by the sol-gel and hydrothermal methods display high RhB photodegradation of 79% and 68%, respectively. The Ba3(PO4)2 obtained using the sol-gel process exhibits much higher stability under light excitation after four regeneration cycles. The photocatalytic oxidation mechanism is proposed based on the active species trapping experiments where O2 •‒ is the most reactive species. The finding shows the promising potential of Ba3(PO4)2 photocatalysts and opens the door for further investigation and application in various photocatalytic applications.

In situ solid-state fabrication of Z-Scheme BiVO4/g-C3N4 heterojunction photocatalyst with highly efficient-light visible activity and their antibacterial properties against bacterial pathogens

Here, BiVO4/g-C3N4 composite photocatalyst with various weight percent of BiVO4 were synthesized by in-situ solid-state fabrication via calcination process. Photocatalyst was characterized by various analytical techniques (XRD, SEM, TEM, UV–vis-DRS, and TGA). The SEM and TEM results showed that composites materials BiVO4 dispersed uniformly on the surface of g-C3N4 sheets, revealing that g-C3N4 sheets was probably a promising support for in-situ growth of nano-size materials. The achieved intimate interfacial contact between BiVO4 and g-C3N4 promoted the charge transfer and inhibited recombination rate of photogenerated electron-hole pairs, which significantly improved the photocatalytic activity. Remarkably, catalytic efficiency of BiVO4/g-C3N4 composites has been demonstrated, via photodegradation of organic pollutants such as rhodamine-B (RhB) and ciprofloxacin (CIP). The 5 wt.% BiVO4/g-C3N4 showed excellent photocatalyst activity and potentially degraded RbB (98 %) and CIP (95 %) in 75 min of irradiation time in the presence of visible light. Moreover, radical trap experiment indicated that the –•O2 and •OH acted as main reactive species for photocatalytic degradation. In addition, BiVO4/g-C3N4 nanocomposite showed strong antibacterial potential against bacterial pathogens; E. coli ATCC-15224, Staphylococcus aureus MTCC-3160 and Pseudomonas aeruginosa PAO1. Studies revealed that depended on time and BiVO4/g-C3N4 concentration, bacterial growth, and viability (CFU count) was consistently declined. The increasing doses of BiVO4/g-C3N4 significantly (p ≤ 0.05) inhibited the virulence factors like pyoverdin, pyocyanin, elastase, exoprotease, rhamnolipid, and swimming motility of P. aeruginosa PAO1 by 76.9, 49.0, 71.1, 53.3, 89.5, and 60 %, respectively. Furthermore, biofilms formed by E. coli, S. aureus and P. aeruginosa PAO1 were maximally inhibited at 10 µgmL−1 BiVO4/g-C3N4 to a maximum of 67, 56 and 56 %, respectively. Also, exopolysaccharide (EPS) releasing ability of isolates were suppressed by BiVO4/g-C3N4. The fluorescently labelled probe DCFH-DA staining of bacterial isolates showed nanocomposite-dependent increase in ROS production and superoxide radicals. The photodegradation of RhB and (CIP) recommends that synthesized BiVO4/g-C3N4 nanocomposite have strong photocatalytic properties. Summarily, newly synthesized BiVO4/g-C3N4 photocatalyst can be employed as an alternative to remediate the environmental pollution as well as a therapeutic agent for topical administration in controlling the pathogenic infections.

Enhancing the visible light absorption of MOF-808 by surface decoration with sulfur and nitrogen co-doped carbon quantum dots: Highly efficient photocatalyst for improved photocatalytic water remediation

Metal-organic frameworks (MOFs) have aroused growing attention in the domain of photocatalysis. However, the photocatalytic performance of MOFs has been severely restricted by their fast recombination of photo-generated electrons and low utilization of solar energy. Combining MOFs with narrow-gap semiconductors can help to overcome their functional shortcomings. In this work, MOF-808 and sulfur and nitrogen co-doped carbon quantum dots (S,N-CQDs) were synthesized using a simple solvothermal technique. Then, novel MOF-808/S,N-CQDs(x) (MS-x) composites were fabricated through a simple solvent-deposition technique to decorate various amounts of S,N-CQDs on the surface of MOF-808. The morphology of MOF-808 and MS-0.5 composite, along with the lattice spacing, and size distribution of decorated S,N-CQDs on MOF-808 surface were investigated by SEM and HR-TEM analyses. According to the UV–Vis DRS and Tauc plots findings, MOF-808 was not photo-active in visible light region because of its large band gap energy (3.85 eV). In contrast, the photocatalytic performance of the prepared composites in Rhodamine B (RhB) degradation was significantly enhanced compared with MOF-808 under visible light irradiation. The results confirmed that S,N-CQDs play a key role in enhancing the visible light absorption efficiency. MS-0.5 composite exhibited the highest photocatalytic activity among the other composites and demonstrated high RhB photodegradation up to 89 % under visible light and 95 % under sunlight irradiation in optimal conditions. According to the kinetic studies, MS-0.5 composite had the highest rate constant, 29.67 and 6.93 times greater than S,N-CQDs and MOF-808, respectively. The scavenger tests revealed that h+ and OH radicals were the main active intermediates in the photocatalytic reaction. In addition, MS-0.5 composite exhibited excellent reusability because only a minor loss of photoactivity was observed after four reaction cycles.

Boosting the performance of LaCoO3/MoS2 perovskite interface for sustainable decontaminants under visible light-driven photocatalysis

The novel composite LaCoO3/MoS2 hybrid nanostructure was synthesized via a combination of sol-gel, hydrothermal, and ultrasonication methods. Alizarin Red S (ARS) and Rhodamine B (RhB) were employed as a model pollutant, to assess the photodegradation efficiency of synthesized catalysts. The effect of MoS2 (2.5%, 5%, 7.5%, and 10%) on LaCoO3 (LCO) and its photocatalytic performance was studied. The properties of synthesized catalysts were assessed using various material characterization techniques. The photocatalytic dye degradation of ARS and RhB was investigated under visible light. Among the synthesized catalyst LM-5% composite (LaCoO3 with 5% MoS2) is determined to be the best photocatalyst as it degrades 96 % (ARS) and 90 % (RhB) in 40 min and 80 min, respectively. The photocatalyst is stable even after multiple runs and exhibits negligible loss in degradation efficiency during the cyclic test. Trapping experiments reveal the significance of superoxide anion and hydroxyl radicals against the photodegradation of ARS and RhB. The kinetics of photodegradation of ARS and RhB by LM-5% is found to be 5.70 × 10−2 and 2.25 × 10−2 min−1, respectively. Herein, we demonstrated a catalyst possessing excellent photodegradation activity which may ignite the possibilities of using efficient photocatalysts for environmental remediation.

Synthesis of g-C3N4/Co3O4@BiVO4 double S-scheme heterojunction photocatalyst for enhanced Rhodamine B degradation with simulated sunlight

The g-C3N4/Co3O4@BiVO4 photo-catalyst was synthesized by green co-precipitation method and used for photocatalytic degradation of Rhodamine B (RhB). It was shown that Co3O4 and BiVO4 form a p-n heterojunction and the band gap energy decreases from 2.578 eV for BiVO4 to 1.564 eV for Co3O4@BiVO4. However, the band gap reduction does not have a significant effect through the g-C3N4 loading. g-C3N4/Co3O4@BiVO4 is more efficient than BiVO4 and Co3O4@BiVO4 at photodegradation of RhB. With a catalyst dose of 0.8 g/L, the removal rate reached 52.6 % after 60 min of simulated sunlight irradiation. The RhB degradation follows a pseudo first-order kinetic law. The S-scheme mechanism was considered in, where g-C3N4 provides a new migration pathway for photoelectrons, favoring the production of electronshole pairs and hydroxyl radicals, as well as the production of superoxide radicals. This study provides a new idea and a new approach for the practical application of BiVO4 photocatalysts.

Synthesis of CuO, ZnO and SnO2 Coupled TiO2 Photocatalyst Particles for Enhanced Photodegradation of Rhodamine B Dye

Environmental pollution is a global problem and dye pollution is one of the major factors. TiO2 shows promising photocatalytic properties that can degrade organic pollutants such as dye under ultraviolet (UV) irradiation. However, TiO2 possesses some disadvantages such as a wide band gap and a high recombination rate of electron-hole pairs. Coupling TiO2 with various metal oxides can enhance photocatalytic properties. In this work, photodepositon (reduction of metal ions on TiO2) followed by the thermal oxidation method were used for the coupling of TiO2 with CuO, ZnO, or SnO2 under various methanol concentrations (25 vol% or 50 vol%) and deposition duration (1 h or 3 h) to observe the effect of these parameters on the photocatalytic degradation activity on Rhodamine B (RhB) dye (up to 90 min). The rate constant of the photodegradation reaction (k) has improved from 0.0141 min−1 (uncoupled TiO2) to 0.0151~0.0368 min−1. Overall, CuO/TiO2 and SnO2/TiO2 samples have shown similar photocatalytic properties (average rate constants of 0.0341 min−1 and 0.0327 min-1, respectively), and both performed better than ZnO/TiO2 in terms of RhB photodegradation (average rate constants of 0.0197 min−1). The difference in photocatalytic performance can be explained by the bandgap of metal oxides and their relative band positions with TiO2. Lastly, CuO/TiO2 (50 vol%, 3 h) and SnO2/TiO2 (50 vol%, 3 h) have shown the best photocatalytic properties respectively due to a longer deposition time and higher concentration methanol, resulting in more deposited materials. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Photodegradation of rhodamine-B in aqueous environment using visible-active gC3N4@CS-MoS2 nanocomposite

Rapid industrial expansion leads to environmental pollution especially in an aqueous environment. Photocatalytic degradation is one of the most efficient and environmentally friendly techniques used to treat industrial pollution due to its complete degradation capability of a variety of water contaminants to their non-toxic state. Graphitic carbon nitride (gC3N4) and molybdenum disulfide (MoS2) provide efficient dye degradation, but MoS2 has few disadvantages. Hence, chitosan (CS) supported gC3N4–MoS2 hybrid nanocomposite was developed in this study to reduce these issues by accelerating the degradation of dye molecules such as rhodamine-B under visible light. The prepared gC3N4@CS-MoS2 hybrid nanocomposite was thoroughly characterized using various analytical tools including FTIR, XRD, SEM, EDX, XPS, UV–Visible, and PL spectra. Several influencing parameters such as irradiation time, initial pH, dosage, and initial dye concentration were optimized by batch mode. The photodegradation of rhodamine-B could be induced by the heterogeneous gC3N4@CS-MoS2-water hybrid nanocomposite. The narrow band gap of gC3N4@CS-MoS2 (1.80 eV) makes it suitable for effective degradation of rhodamine-B due to more active in the visible region and attained its highest degradation efficiency of 99% after 40 min at pH 8 with minimum dosage of 60 mg. The possible degradation mechanism was tentatively proposed for rhodamine-B dye molecules from aqueous environment. The present work shows a novel photocatalyst for the purification and detoxification of dye molecules as well as other water contaminants found in polluted wastewater.

Influence of Radical Scavenger on Radiation Synthesis of Graphene Oxide/TiO2 Nanotubes/Ag Nanoparticles Nanocomposites and Their Dye Photodegradation Efficiency

Aqueous solutions of graphene oxide (GO), TiO2 nanotubes (TNTs), and silver nanoparticles (AgNPs) were synthesized through a facile, single-step radiolytic method at room temperature and ambient pressure. The resulting material, referred to as GO-TNTs-AgNPs (GTA), was investigated for its potential application in the photodegradation of Rhodamine-B (RhB) dye. This synthesis process relies on the interaction of high-energy gamma rays from a 60Co source with the water in the aqueous solutions. The main objective of this study was to evaluate the effect of irradiation dose and the presence of polyethylene glycol (PEG) solution on the combination within the nanocomposite materials. The inefficiency of GTA synthesis experimentally was in agreement with the hydroxyl radical (HO•) scavenger. Then, the irradiated materials were structurally characterized using various spectroscopic methods (Fourier transform infrared (FTIR), X-ray diffraction (XRD), Raman spectroscopy, and ultraviolet-visible absorption (UV–Vis)). Scanning electron microscopy (SEM) studies reveal the variable morphology of nanocomposites. GTA samples in water exhibited significantly higher degradation efficiency on Rhodamine B dye under natural sunlight irradiation conditions.

Size‐Dependent Structural, Optical and Photocatalytic Properties of Zirconium Ferrite Prepared via a Sol‐Gel Route

AbstractZirconium ferrite (ZrFe2O4) nanoparticles with different sizes (43, 56 and 69 nm) were synthesized by the sol‐gel synthesis technique after calcination at 400, 600 and 800 °C, respectively. The X‐ray diffraction (XRD) method was used to study the change in crystal structure with temperature andrevealed the increase inaverage crystallite sizewith the increase in calcination temperature.Scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDX) were used to investigate the morphology and elemental analysis. The SEM study confirmed the spherical shape and homogenous distribution of the nanoparticles.The optical band gap reduced from 2.5 eV to 2.24 eV with an increase in particle size from 43 to 69 nm, studied using UV‐Vis spectroscopy.The ZrFe2O4 nanoparticles with smaller particle size displayed better photocatalytic activities than that with larger particle size for the degradation of hazardous dyes methylene blue (MB) and rhodamine B (RhB) under UV radiation. The photodegradation of MB and RhB catalyzed by the ZrFe2O4 nanoparticles was a pseudo‐first‐order reaction. The maximum degradation for MB and RhB was 70 % and 95 %,respectively, in just 120 minutes for the sample having the smallest size due to its large surface area.This study confirmed that the ZrFe2O4 nanoparticles are apromisingcandidate for the catalysis of organic dyes through the redox reaction.

A flexible and easily recyclable polyacrylonitrile/Cd0.8Zn0.2S/SnO2 nanofibrous mat for visible-light driven photodegradation of RhB

Constructing photocatalyst with high visible light utilization efficiency and easy recyclability is still challenging in view of practical applications. Herein, we constructed a novel Cd0.8Zn0.2S/SnO2 heterojunction on flexible PAN nanofiber substrates via a simple solvothermal route as a flexible and easily recycled photocatalyst. This newly developed PAN/Cd0.8Zn0.2S/SnO2 nanofibrous mat had excellent photocatalytic activity towards Rhodamine B (RhB) under visible light driving, and RhB could be degraded 98 % after 120 min. The efficient photocarrier separation endowed by Cd0.8Zn0.2S/SnO2 heterojunction plays a significant role in improving photocatalytic property. Meanwhile, the obtained PAN/Cd0.8Zn0.2S/SnO2 nanofibrous mat had good structural stability and cycling performance. More importantly, relative to the traditional suspended nanoparticles, the film-like PAN/Cd0.8Zn0.2S/SnO2 exhibit outstanding flexibility and self-supporting characters, allowing them to be effortlessly separated and removed from service environment. This work provides an excellent strategy for designing flexible and recyclable nanofiber based photocatalysts with high photocatalytic activity, which is expected to have broad application prospects in the field of water treatment.

In-situ construction of Sn-doped BiOCl/Bi2WO6 heterojunction for excellent organic pollutants degradation: Insight into performance and mechanism

Heterojunction formation and metal doping are two prospective strategies for accomplishing efficient separation of charges. However, the photogenerated carriers’ separation efficiency still has space for ascension when one of them is utilized alone. In this study, Sn-BiOCl/Bi2WO6 composite was constructed by tin chloride etching to investigate the synergy of heterojunction and metal doping toward the elevated of photogenerated carrier’ separation efficiency. The Sn2+/Sn4+ redox couple and heterojunction interface promotes the charges separation and reactive oxygen species (ROS) generation, leading to the Sn-BiOCl/Bi2WO6 exhibits 2.75 and 1.95 times of photodegradation rates towards rhodamine B (RhB) compared to Bi2WO6 and BiOCl/Bi2WO6. Meanwhile, the Sn-BiOCl/Bi2WO6 behaves photocatalytic activation effect on bicarbonate and sulfite to boost excessive ROS generation during the process of photocatalytic degradation of ciprofloxacin (CIP). Furthermore, the possible RhB and CIP photodegradation pathways over Sn-BiOCl/Bi2WO6 were further explored by MS spectra. This study offers a reliable method to develop highly efficient photocatalyst for environmental remediation.

S-scheme Ag/ZnO/CeO2 inverse opal photonic crystals with enhanced photocatalytic properties

Construction of S-scheme heterojunctions and increasing the specific surface area are considered effective strategies to enhance photocatalytic performance. In this work, ZnO and ZnO/CeO2 with inverse opal structure were constructed by the high-temperature template removal method. Then a simple UV photoreduction method was used to construct the photocatalysts with Ag/ZnO/CeO2 inverse opal (Ag/ZnO/CeO2 IO). The degradation behavior of the composite for rhodamine B (RhB) was investigated. Specifically, the photodegradation of RhB by Ag/ZnO/CeO2 exhibited good photostability and the best removal efficiency compared with ZnO inverse opal (ZnO IO) and ZnO/CeO2 inverse opal(ZnO/CeO2 IO), which was 2.7 times higher than that of ZnO IO. The synergetic effect of the composite effectively improves the electron adsorption capacity, and the surface plasmon resonance (SPR) effect of Ag nanoparticles enhances its photo availability, thus improving the photocatalytic activity. This work provides a new strategy for ZnO-based composites in degrading wastewater pollution.

Enhanced Photodegradation of Rhodamine B Using Visible-Light Sensitive N-TiO2/rGO Composite

Rhodamine B (RhB) is extensively used for dyeing purposes, and cannot be completely removed using traditional water treatment technologies. Here, we report for the first time the photodegradation of RhB using nitrogen-doped titanium dioxide (N-TiO2) on reduced graphene oxide (rGO) composite (N-TiO2/rGO). The work primarily highlights the synergistic effect of the incorporation of N-TiO2 and rGO and its kinetic study for the photodegradation of RhB. The N-TiO2/rGO composite was synthesized by dispersing titanium(IV) isopropoxide and urea, followed by annealing treatment via the hydrothermal method with rGO. Scanning electron microscopy (SEM) images illustrated that N-TiO2 particles with an irregular round shape and white color were dispersed onto the rGO surface. X-Ray diffraction (XRD) patterns revealed that N-TiO2/rGO composite showed an anatase phase of TiO2 with a diffraction peak of 2θ = 25.622°. The gas sorption analysis (GSA) showed that N-TiO2/rGO had surface area, pore volume, and pore size of 53.393 m2/g, 0.096 cc/g, and 3.588 nm, respectively. The thermogravimetric-differential thermal analysis (TG-DTA) showed an anatase phase of TiO2 that appeared at a temperature of 200–500 °C, with a weight loss of 2.50%. According to the ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) study, TiO2, N-TiO2, and N-TiO2/rGO had band gap energies of 3.25, 2.95, and 2.86 eV, respectively. The highest photodegradation of RhB was obtained at the optimum condition in pH 2 with a photocatalyst mass of 20 mg and an irradiation time of 90 min. The photocatalytic activity of N-TiO2/rGO using visible light showed a higher percentage of photodegradation at 78.29%, compared to 44.08% under UV light. The kinetic study of the photodegradation of RhB using N-TiO2/rGO followed the pseudo-second-order model.

Synthesis and physicochemical evaluations of a novel MIL-101(Fe)-PMA-Biochar triple composite photocatalyst activated through visible-light and utilized toward degradation of organic pollutants: optimal operations and kinetics investigations.

A triple photocatalytic composite of biochar, metal-organic framework, and phosphomolybdic acid was prepared through hydrothermal treatment of iron (III) chloride hexahydrate, terephthalic acid, lavandulifolia-derived biochar, and phosphomolybdic acid. It was characterized and utilized for photodegradation of Rhodamine-B (RhB) dye under visible-light irradiation. Investigations of reaction variables confirmed that, the highest yield of 96.2% was achieved at ambient temperature using 0.07g of catalyst at pH of 7, and a dye concentration of 10ppm. Under these optimum conditions, Methyl Orange (MO) dye was also degraded to yield 93% removal. In addition, the kinetic and thermodynamic parameters for RhB were determined. It was revealed that the photodegradation of RhB followed a pseudo-first-order kinetics with no mass transfer limitations. A corresponding chemical mechanism for this process was also suggested. Adsorption isotherms were investigated for rate of adsorption as well as adsorption capacity of the catalyst under dark conditions. Notably, the catalyst could have been reused for five cycles with a loss of around 20% activity.

Photocatalytic investigation of textile dyes and E. coli bacteria from wastewater using Fe3O4@MnO2 heterojunction and investigation for hydrogen generation on NaBH4 hydrolysis

Various impurities found nowadays in water can be detrimental to human health. This work focused on utilizing Fe3O4@MnO2 nanocomposite for cleaning organic contaminants from water, including rhodamine B (RhB) and Escherichia coli (E. coli). Analysis methods such as XRD, UV–vis, TEM, and FTIR were used to describe the nanocomposite. The results showed that the developed nanocomposite has good photocatalytic activity against pollutants in wastewater. The E. coli was destroyed after 90 min, and the RhB photodegradation rate was 75%. Moreover, the Fe3O4@MnO2 efficiency as a catalyst for producing hydrogen as an alternative energy source was tested. According to the calculations, the nanomaterial's turnover frequency, activation energy, enthalpy, and entropy are 1061.3 h−1, 28.93 kJ/mol, 26.38 kJ/mol, and −128.41 J/mol.K, respectively. Four reusability tests were completed, and the average reusability was 78%. The obtained data indicated the excellent potential for the developed Fe3O4@MnO2 nanomaterial to act as an adsorbent, thus representing an alternative to the classical depollution methods. This study showed that nanoparticles have a photocatalytic effect against pathogenic bacteria and RhB azo dye in polluted waters and offer an effective catalytic activity to produce hydrogen as an alternative energy source.

Ba2-xHoxSr2-yNiyFe12O22 and its composite with MXene: synthesis, characterization and enhanced visible light mediated photocatalytic activity for colored dye and pesticide.

The rapid recombination of charges of photogenerated electrons and holes severely limits single semiconductor photocatalytic applications. In this study, a simple and facile sol-gel approach was used to synthesize Ba2-xHoxSr2-yNiyFe12O22 (x = 0, 0.1 and y = 0, 0.5). The composite of holmium-nickel doped barium-strontium ferrite with MXene (Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene) was synthesized by ultrasonication method. These synthesized samples were subsequently used to photodegrade rhodamine B (RhB) and pendimethalin under visible light illumination. The results of the experiments demonstrated that MXene, as a cocatalyst, considerably reduces the rate of recombination of charges and broadens absorption of visible light by providing increased surface functional groups to improve the photocatalytic activity of synthesized samples. MXene is thermally stable, have high electrical conductivity, have adjustable bandgap, and hydrophilic in nature. The optimized Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene composite demonstrated an excellent photocatalytic rate by degrading 78.88% RhB and 75.59% pendimethalin in 140 minutes. Moreover, the scavenging experiment revealed that photogenerated electrons and holes were the primary active species involved in RhB and pendimethalin photodegradation, respectively. Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene showed increased photocatalytic behavior because it has increased surface area which decreases rate of recombination of electron and hole pair, hence photocatalytic activity increases. It is observed that Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene has potential application in photocatalytic degradation of harmful pollutants.

Ag2NCN anchored on Ti3C2Tx MXene as a Schottky heterojunction: enhanced visible light photocatalytic efficiency of rhodamine B degradation.

The quick charge recombination of light-generated electrons and holes severely restricts the photocatalytic applications of single semiconductors. Here, a straightforward electrostatically driven self-assembly technique was used to construct an Ag2NCN/Ti3C2Tx Schottky heterojunction, which was then used to degrade Rhodamine B (RhB) in the illumination of visible light. The findings from the experiments revealed that as a cocatalyst, Ti3C2Tx significantly suppresses the recombination rate and broadens visible absorptivity to improve Ag2NCN photocatalytic efficiency. The optimized Ag2NCN/Ti3C2Tx (AT2) composite exhibited an outstanding photocatalytic rate in 96 min, with the highest RhB degradation rate (k = 0.029 min-1), which was around fifteen times that of pure Ag2NCN (k = 0.002 min-1). Furthermore, the trapping-agent experiment showed photogenerated superoxide radicals and holes were the principal active agents inside the photodegradation of RhB. Compared with Ag-based semiconductors, the composite exhibited outstanding photostability, highlighting its excellent potential for application in visible-light photocatalysis.

Straightforward synthesis and mechanism insight of TiO2/α′-AgVO3 heterostructure with enhanced photocatalytic activity

With the deterioration of our environment, it is imperative to develop high-performance photocatalysts for ‘green’ environmental protection. In this work, a novel TiO2/α′-AgVO3 heterostructure has been successfully synthesized by a straightforward hydrothermal method for the photodegradation of Rhodamine B (RhB). Specifically, TiO2/α′-AgVO3 with a molar ratio of 4:1 displays excellent stability and outstanding photodegradation efficiency, which can remove 94% RhB within 120 min visible light irradiation. The free radical capture experiments demonstrate that h+ and ·OH act as pivotal parts in the photodegradation of RhB. Additionally, the enhanced photocatalytic performance of TiO2/α′-AgVO3 heterostructure is mainly attributed to the appropriate surface areas, broadened range of light adsorption, more photocarrier generation, and effective charge separation. This research reveals that TiO2/α′-AgVO3 heterostructure is an efficient visible light photocatalyst and is expected to be applied in organic sewage degradation.

Perovskite LaNiO3/Ag3PO4 heterojunction photocatalyst for the degradation of dyes.

Pristine lanthanum nickelate (LaNiO3), silver phosphate (Ag3PO4) and perovskite lanthanum nickelate silver phosphate composites (LaNiO3/Ag3PO4) were prepared using the facile hydrothermal method. Three composites were synthesized by varying the percentage of LaNiO3 in Ag3PO4. The physical properties of as-prepared samples were studied by powder X-ray diffraction (pXRD), Fourier-transform infrared (FT-IR), Scanning electron microscopy (SEM) and Energy-dispersive X-ray (EDX). Among all synthesized photocatalysts, 5%LaNiO3/Ag3PO4 composite has been proved to be an excellent visible light photocatalyst for the degradation of dyes i.e., rhodamine B (RhB) and methyl orange (MO). The photocatalytic activity and stability of Ag3PO4 were also enhanced by introducing LaNiO3 in Ag3PO4 heterojunction formation. Complete photodegradation of 50mg/L of RhB and MO solutions using 25mg of 5%LaNiO3/Ag3PO4 photocatalyst was observed in just 20min. Photodegradation of RhB and MO using 5%LaNiO3/Ag3PO4 catalyst follows first-order kinetics with rate constants of 0.213 and 0.1804min-1, respectively. Perovskite LaNiO3/Ag3PO4 photocatalyst showed the highest stability up to five cycles. The photodegradation mechanism suggests that the holes ( h +) and superoxide anion radicals plays a main role in the dye degradation of RhB and MO.