Degradation Rate Of Rhodamine B Research Articles

Hydrothermal preparation of magnetic recyclable In-doped MoO3/SrFe12O19 ternary nanocomposites with enhanced visible-light-driven photocatalytic performance

SrFe12O19 as a novel magnetic matrix has drawn increasing attention in photocatalysis. In the current study, a novel magnetically recoverable In-MoO3/SrFe12O19 ternary composite photocatalyst was fabricated with the hydrothermal method, and the photocatalytic activity was evaluated by degrading rhodamine B (RhB) solution through simulated solar irradiation. The results demonstrated that the outstanding degradation rate of RhB (96.5%) could be achieved within 70 min when the mass ratio of both doped In and SrFe12O19 in the ternary composite photocatalyst was 5% (5-IMS-5). The enhancement of the photocatalytic degradation performance was mainly related to the self-sensitization of RhB, the magnetic field effect of SrFe12O19, and the introduction of impurity energy levels by In doping. More importantly, the degradation rate of RhB by 5-IMS-5 was still up to 90.8% after 4 times of recycling, verifying that the prepared ternary composite sample has good recyclability and stability. This study proves a novel ternary composite photocatalyst that can be used for organic wastewater treatment, and its photocatalytic degradation mechanism provides great reference significance for the synthesis of other SrFe12O19-based magnetic semiconductor photocatalysts.

Visible-light-induced degradation of rhodamine B by double Z-scheme magnetic ATP-g-C3N4/SnFe2O4/Bi2WO6 heterojunctions: Performance and mechanism

A magnetic ternary double Z-scheme ATP-g-C3N4/SnFe2O4/Bi2WO6 (AG/SFO/BWO) heterojunction was prepared by a simple and green hydrothermal process, which was successfully used in the dye degradation. AG/7.5 %SFO/BWO catalyst demonstrated outstanding visible-light-induced degradation, achieving an impressive 96.72 % degradation of rhodamine B (RhB) in 2 h. Compared with Bi2WO6 (BWO) and SnFe2O4/Bi2WO6 (SFO/BWO), the degradation efficacy was increased about 1.65 and 1.16 times, respectively. After being used for five batches, the degradation rate of RhB remained over 90 %. Moreover, AG/7.5 %SFO/BWO showcased remarkable efficacy in degrading methylene blue (MB), Congo red (CR), and tetracycline (TC). Bacterial toxicity test indicated the toxicity of dyes was rapidly decreased in 24 h. Physicochemical properties and morphological characteristics of the prepared photocatalysts were investigated by various methods, including XRD, FTIR, XPS, SEM, TEM, BET, VSM, UV–vis, and EIS. AG/7.5 %SFO/BWO, utilizing a dual-Z scheme pathway, efficiently absorbed broad light, yielding multiple active agents, primarily hole (h+) and superoxide radical •O2−. The double Z-scheme heterojunction structure enhanced the electron-hole separation and ensured a stable photochemical environment. UPLC-HRMS was used to identify intermediates during the RhB degradation. Its degradation pathway and catalytic mechanism were illustrated systematically. The bio-toxicity (acute toxicity, developmental toxicity, and mutagenicity) of the intermediates was also evaluated by T.E.S.T.

Preparation of Fe3O4@CA/BNNS/AgNP Magnetic Microspheres and Photocatalysis of Dyes.

In this work, sea urchin-like magnetic Fe3O4@CA/BNNS/AgNP composite microspheres were successfully prepared. The photocatalytic performance of composite microspheres for the organic dye rhodamine B (RhB) was systematically investigated under different conditions, and the catalytic degradation rate of RhB was as high as 95% within 60 min; after three cycles of recycling, the degradation rate of RhB was reduced by only 8%. The main active agents in the reaction are e- and •O2-. Fe3O4@CA/BNNS/AgNP microspheres prepared in this study exhibit photocatalytic and electrochemical properties, making them easy to separate. This work is not limited to the development of Fe3O4-based catalysts but also is expected to provide ideas for the research and progress of photocatalytic composite catalysts with electrochemical properties.

Highly efficient visible-light driven dye degradation via 0D BiVO4 nanoparticles/2D BiOCl nanosheets p-n heterojunctions

The construction of hybrid heterojunction photocatalysts is an effective strategy to improve the utilization of photogenerated carriers and photocatalytic activity. To enhance the separation distance of photogenerated carriers and accelerate the effective separation at the heterojunction of the interface, a unique 0D-2D hierarchical nanostructured p-n heterojunction was successfully fabricated in this work. BiOCl (BOC) nanosheets (p-type) were in situ grown on BiVO4 (BVO) nanoparticles (n-type) using the microemulsion-calcination method for highly efficient visible-light-driven organic dye degradation. Compared with pure BVO (the degradation rate of rhodamine B (RhB): about 32.0% in 55 min, the mineralization rate: 24.9% in 120 min), the RhB degradation rate can reach about 99.5% in 55 min and the mineralization rate of 62.1% in 120 min by utilizing BVO/25%BOC heterojunction photocatalyst under visible light irradiation. Various characterizations demonstrate that the formation of BVO/BOC p-n heterojunction greatly facilitates photogenerated carriers separation efficiency. Meanwhile, the results of the scavenging experiments and electron spin resonance tests indicate that ·O2− and h+ are the prominent active species for Rh B degradation. In addition, possible degradation pathways for Rh B were proposed using LC-MS tests. This work proves that building low dimensional p-n heterojunction photocatalysts is a promising strategy for developing photocatalysts with high efficiency.

Self-templating approach to Co9S8 hexagonal sheets via Kirkendall effect with efficient photocatalytic performance

The Co9S8 Hexagonal Sheets (HSs) with an average side length of approximately 1 μm have been successfully prepared by a one-step hydrothermal route. XRD, FESEM, XPS, BET and UV–Vis spectra were used to analyze the crystal structure, morphology, surface element states, specific surface area and optical properties of the products. An SRS (Hexagonal Sheets-Hexagonal Rings-Hexagonal Sheets) growth mechanism of Co9S8 HSs was proposed based on the Kirkendall effect. The formation of Co9S8 HSs attributed to the gradual diffusion of Co2+ outward from the inner and S2- from outside into the core. The Co9S8 HSs exhibited excellent photocatalytic activity to degrade Rhodamine B (RhB) due to the larger specific surface area (13.74 m2/g) and lower band-gap (1.28 eV). The degradation rate of RhB (25 mg/L) reached 95 % in 60 min for Co9S8 HSs. After four cycles of degradation, the degradation rate can reach up to 90 %, indicating that Co9S8 HSs have good reusability. Furthermore, given radical quenching experiments and photocatalytic reactions, the degradation mechanism of Co9S8 HSs was also analyzed in detail. This work may enlighten the design and fabrication of nanomaterials for various applications.

Construction of Co-doped Fe2O3/carbonized melamine foam heterogeneous catalyst for enhanced degradation of organic pollutants through peroxymonosulfate activation

Co-doped Fe2O3/carbonized melamine foam heterogeneous catalyst (CMF/Co-Fe2O3) was prepared by hydrothermal method. Rhodamine B (RhB) degradation was employed as a model test for evaluating peroxymonosulfate (PMS) activation. The degradation efficiency of RhB can reach 97 % in the catalyst dosage (50 mg/L), PMS concentration (100 mg/L), pH = 7 and RhB initial concentration (10 mg/L) after 60 min reaction. The reaction rate constant is 10 times higher than that of CMF/Fe2O3 and the activation ability of PMS is greatly improved. The degradation efficiency of RhB can be inhibited by increasing the initial mass concentration of RhB and pH value. The effect of temperature on the degradation rate of RhB conforms to the Arrhenius model, and the degradation process is a surface reaction controlled process. The results of free radical capture experiments and electron paramagnetic resonance (EPR) experiments showed that SO4¯ was the main active free radical for RhB degradation. After four cycles, the degradation efficiency of RhB still maintains 80 % with CMF/10 %Co-Fe2O3 catalyst. The heterogeneous catalyst exhibited potential application in the field of degradation of dye wastewater due to its excellent cycling stability.

Citric acid–enhanced Fe2+ and Cu2+ synergistic activation of persulfate for rhodamine B degradation

Citric acid (CA) and Cu2+ were used to enhance Fe2+-activated persulfate (PDS) for rhodamine B (RhB) oxidative degradation. The effects of PDS concentration, Fe2+ concentration, CA concentration, Cu2+ concentration, pH, and common inorganic anions in water on PDS activation and RhB degradation were investigated. Results showed that sulfate and hydroxyl radicals were the primary active substances in the reaction system, with sulfate radical playing a key role. The addition of CA and Cu2+ improved the efficiency of RhB decomposition, achieving a removal rate of 98.4% after 30 min of reaction, governed by pseudo-first-order. The presence of a complexing agent, allows effective RhB removal over a wide pH range. The free sulfate radical (SO4·−) concentration increases with increasing Fe2+ concentration. However, when the Fe2+ concentration was higher than 0.5 mM, self-quenching of SO4·− occurred and the RhB degradation rate decreased. In contrast, with increasing PDS concentration, the degradation rate of RhB continued to increase. The radical process was the main mechanism of RhB decomposition. Analysis of intermediates showed that C–C and C–N bond cleavage was the most likely degradation mode for contaminants to become small molecules.

Structural Diversity Design, Four Nucleation Methods Growth and Mechanism of 3D Hollow Box TiO2 Nanocrystals with a Temperature-Controlled High (001) Crystal Facets Exposure Ratio.

Three-dimensional (3D) hollow box TiO2 nanocrystals with structural diversity have been designed and grown by four nucleation methods, including the acid dissolution denucleation method with Fe2O3 as heterogeneous nucleation, the topological phase transition method, the sonic solvothermal method, and the air atmosphere sintering method with TiOF2 as homogeneous nucleation. Through full morphology analysis and structural characterization, reasonable growth mechanisms of 3D hollow box TiO2 nanocrystals were proposed, including nucleation dissolution, Oswald ripening, and hydrolysis reactions. It was found that the high energy (001) crystal facets exposure ratio was closely correlated with reaction temperature of four nucleation-methods, which even reached 92% for the first time. Under simulated sunlight irradiation, their hydrogen production performance and photocatalytic degradation efficiency on model dye molecules rhodamine B (RhB) and methylene blue (MB) were evaluated, and as-prepared hollow box TiO2 nanocrystals prepared by the sonic solvothermal method exhibited the best photocatalytic performance, with a hydrogen production rate of 93.88 μmol/g/h. Within 70 min, the photocatalytic degradation rates of RhB and MB reached 96.59 and 75.25%, respectively, which were 5.74 and 5.54 times that of P25. Their properties are closely connected with the orderly cubic and hierarchy configuration structure of hollow box TiO2 nanocrystals, which have a high exposure ratio of (001) facet controlled by reaction temperatures, thereby greatly improving the photocatalytic activity. This study provides a classic reference for improving the properties of hollow box TiO2 nanocrystals through structural diversity design and various methods of nanocrystal growth.

Magnetic perovskite nanohybrid based on g-C3N4 nanosheets for photodegradation of toxic environmental pollutants under short-time visible irradiation

In this study, a magnetic perovskite nanohybrid based on g-C3N4 (gCN) nanosheets was synthesized and developed for the efficient photodegradation of toxic environmental pollutants under short-time visible irradiation. The synthesis of this nanohybrid involved the incorporation of SrTiO3:N (STO:N) and ZnFe2O4 (ZnF) onto the g-C3N4 nanosheets through a simple reflux method. Our investigation encompassed a comprehensive suite of analytical techniques, including BET, TGA, TEM, SEM, EDX, DRS, VSM, XRD, photocurrent, and FT-IR, to elucidate the physicochemical characteristics of this nanocomposite in the context of its application in photodegradation processes. The nanohybrid displayed significantly enhanced photocatalytic activity compared to its individual components, achieving a degradation efficiency of over 90% for various pollutants, including organic dyes like Rhodamine B (Rh-B), within a short irradiation time. This enhanced activity can be attributed to the synergistic effect between gCN, STO:N, and ZnF, which promotes the generation of reactive oxygen species and facilitates the degradation process. Notably, the nanocomposite containing 20 wt% STO:N perovskite and 20 wt% ZnF demonstrated the highest Rh-B degradation rate under visible light irradiation within just 30 min. Furthermore, the nanohybrid displayed excellent stability and reusability over seven consecutive runs, retaining its high photocatalytic activity even after multiple cycles of degradation. This remarkable performance can be attributed to the strong interaction between the gCN nanosheets and the magnetic perovskite components, which prevents their aggregation and ensures their efficient utilization. Additionally, the nanohybrid exhibited excellent visible light absorption, enabling the utilization of a wider range of light for degradation. This feature is particularly advantageous, as visible light is more abundant in sunlight compared to UV light, rendering the nanohybrid suitable for practical applications under natural sunlight. In conclusion, the ternary gCN-STO:N@ZnF nanocomposite represents a promising candidate for the treatment of organic pollutants in aqueous environments, offering a versatile and efficient solution.

Preparation and enhanced photocatalytic performance of N-TiO2/g-C3N4 heterostructure for Rhodamine B degradation

Highly efficient photocatalysts have been developed for the degradation of contaminated water under visible light. In this study, N-doped TiO2 (N-TiO2) and metal-free graphitic carbon nitride (g-C3N4) composites with various Ti/C molar ratios were prepared with the simple mixing-calcining method. The samples were characterized by X-ray diffraction, scanning electron microscopy, ultraviolet–visible diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The photocatalytic activity of N-TiO2/g-C3N4 in the degradation of Rhodamine B (RhB) was investigated, and the electrochemical method was used to determine the origin of the enhanced photoactivity of N-TiO2/g-C3N4. The results showed that N-TiO2 nanoparticles were dispersed on the surface of g-C3N4 and formed a stable heterojunction structure with g-C3N4. The heterojunction between the two semiconductors could effectively prevent the recombination of photogenerated electrons and holes and improve the photocatalytic efficiency of the photocatalyst under visible light irradiation. The photocatalyst exhibited high stability, and the RhB degradation rate was still higher than 82.3% after five cycles.

Oxidative degradation of Rhodamine B solution with nZVI persulfate activation

In this study, the researchers evaluated the use of nano-zero-valent iron (nZVI) activated persulfate (PS) for the degradation of Rhodamine B (RhB). The effects of various operating parameters such as initial pH, and dosages of PS, nZVI and citric acid (CA) on the removal rate of RhB were investigated. The results demonstrated that at a PS dosage of 5 mmol·L<sup>-1</sup>, nZVI dosage of 0.3 g·L<sup>-1</sup>, 0.1 mmol·L<sup>-1</sup> CA, and pH of 5, the degradation rate of RhB was 94.970%. The degradation and kinetic analysis of RhB using micron-scale zero-valent iron (mZVI) and nZVI revealed that nZVI exhibited higher activity with PS due to its smaller particle size. The activation of PS by nZVI is higher compared to mZVI, and the ineffective consumption is half that of the mZVI/PS system, the TOC removal rate increased by 18.65%. Kinetic analysis indicated that under the mentioned reaction conditions, the degradation process followed a pseudo-second-order reaction model, with the highest apparent reaction rate constant (kobs). The researchers also identified active radical species in the nZVI/PS system. Additionally, Gas Chromatography-Mass Spectrometry (GC-MS) analysis was used to detect reaction intermediates and propose a possible degradation pathway for RhB.

Preparation and photocatalytic activity of Ti(I/S) catalyst etched by different acids and alkalis

The surface of clay contains a large number of hydroxyl groups and adsorption sites, providing favorable conditions for the further modification to obtain efficient photocatalysts. TiO2 pillared illite/smectite (I/S) (Ti(I/S)) clay was etched by thiourea (CH4N2S), urea (CH4N2O), boric acid (H3BO3), and phosphoric acid (H3PO4) to increase its specific surface area. SEM and TEM results showed that there was no obvious etching on the surface of Ti(I/S), but the specific surface area of Ti(I/S) (50.1 m2/g) was improved after etching by different acids and alkalis. The specific surface area of Ti(I/S)–CH4N2S, Ti(I/S)–CH4N2O, Ti(I/S)–H3BO3, and Ti(I/S)–H3PO4 was 67.6 mg2/g, 52.9 m2/g, 53.2 m2/g, and 53.1 m2/g, respectively. Ti(I/S)–CH4N2S had higher photocatalytic activity for Rhodamine B (RhB) degradation than that of Ti(I/S)–CH4N2O, Ti(I/S)–H3BO3, and Ti(I/S)–H3PO4. The degradation rate of RhB by Ti(I/S)–CH4N2S-3 was 82% after 120 min, and Ti(I/S)–CH4N2S-3 had good chemical stability. The main active species for RhB degradation was ·O2−, and the possible photocatalytic mechanism was also described.

Cobalt-doped Graphene-supported Nanoscale Zero-valent Iron: Removal of Rhodamine B solution and mechanistic study

nZVI materials loaded on GO have been applied to the treatment of difficult-to-degrade organics due to their higher electron transfer rate. However, cobalt doping of GO/nZVI composites and the effect of the doped materials on difficult-to-degrade organics are not known. In this work, Cobalt-doped Graphene-supported nanoscale Zero-valent Iron (GO/nZVI-Co) was successfully synthesized via the liquid-phase reduction-suspension self-assembly method, which was composited with theoretical mass ratio of GO:nZVI:Co = 1:2:0.08. And GO/nZVI-Co was used as efficient heterogeneous catalyst for degradation of Rhodamine B (RhB) via H2O2. Characterization results show that nZVI and Co particles were successfully loaded on GO nanosheets increasing the dispersibility of particles. Under the optimal reaction conditions(the mass ratio of GO: nZVI = 1:2 and Co doping is less than 1/5), the RhB degradation rate was as high as 98.28 %. The degradation pathways of GO/nZVI-Co-HP system could better explained by the secondary kinetic model and GC–MS spectru. The main effect of cobalt doping in the GO/nZVI-Co-HP system is to increase the adsorption properties of the material on H2O2, and this facilitates the contact reaction of nZVI with H2O2. In this study, a GO/nZVI-Co material with improved electron transfer efficiency was prepared and its removal mechanism of pollutants was elucidated to provide relevant theoretical support for the treatment of difficult-to-degrade wastewater.

Enhanced photocatalytic performance and mechanism of N-deficiently porous g-C3N4 in organic pollutant degradation

N-deficiently porous graphitic carbon nitride (g-C3N4) was synthesized from the mixture of melamine and urea through a one-pot co-polymerization procedure. In particular, UMCN, which was prepared with a mass ratio of 1 : 5 for melamine to urea, possesses a ultrahigh specific surface area of 183.7 m2/g. The unique structure can offer more surface active sites, narrow the bandgap, as well as enhance the separation and migration of photogenerated carriers. Consequently, UMCN exhibited fascinating photocatalytic activity in the degradation of rhodamine B (RhB), and the corresponding removal rate reached 99.3% within 30 minutes irradiated by visible light. Also, the optimal material demonstrated excellent recyclability, and the degradation rate of RhB still remained as high as 95.6% even in the 7th run. Also, UMCN presented desirable universality in eliminating other organic contaminants. This work provides a facile strategy for synthesizing high-performance g-C3N4-based photocatalyst material towards the elimination of environmental pollutants.

Modulating Catalyst‐Reactant Interface Microenvironment for Efficient Photocatalysis on Bismuth Sulfide

AbstractPollution by organic dyes has received extensive attention due to their high toxicity, biohazard, and high stability in the natural environment, and the development of high‐efficiency dye degradation and heavy metal ion reduction technologies is urgently needed in photocatalysis. However, the interface microenvironment between catalyst and pollutant is often ignored, and the poor compatibility of the catalyst‐pollutant interface constrains further efficient catalysis. Herein, to improve the compatibility of the catalyst‐pollutant interface, a surfactant‐capping strategy for enhanced photocatalysis of rhodamine B (RhB) on one‐dimensional rod‐like Bi2S3 nanocrystals was investigated. Specifically, polyvinylpyrrolidone (PVP)‐capped Bi2S3 (Bi2S3‐PVP) showed enhanced RhB degradation rate compared with pure Bi2S3, and further studies suggested enhanced reaction interface compatibility at the Bi2S3‐PVP‐RhB interface. This work provides an interface microenvironment modulation strategy for improving photocatalytic performance towards organic dyes.

Ball mill-hydrothermal method for one-step synthesis of zinc oxide/carbon quantum dot (ZnO-CQD) nanocomposites as photocatalyst for degradation of organic pollutants

In this work, we report a cost-effective, green, one-step, and new method without any extra materials to prepare ZnO/CQD photocatalyst. Hence, ZnO nanoparticles and zinc oxide/carbon quantum dot (Z-CQD) nanocomposites were synthesized using zinc salt, KOH, and sucrose through the new green ball mill-hydrothermal method. The prepared nanomaterials were characterized by FT-IR, TEM, XRD, FE-SEM, TGA, and UV–Vis absorption. The analysis of the TGA result shows the presence of around 6 wt% of CQD in Z-CQD nanocomposite. The presence of CQD in ZnO nanoparticles decreased the bandgap. The photocatalytic performance of ZnO and Z-CQD were compared by evaluating the degradation of phenazopyridine (PhP), a drug pollutant, and rhodamine B (RhB), an organic dye pollutant, under UV light. The results showed that the degradation rate of RhB is higher than that of PhP. In addition, in the case of RhB, the degradation rate by Z-CQD is higher than that of pure ZnO. Therefore, the presence of carbon quantum dots showed a positive effect on the rate of photocatalytic degradation.

Fabrication of Ternary Ag/g‐C3N4/BiVO4 Composites with Enhanced Visible‐Light‐Driven Photocatalytic Activity toward Rhodamine B Elimination

AbstractBiVO4 and g‐C3N4 have gain attention for their potential in sustainable energy and environmental applications due to their visible light absorption properties. However, their limitations in terms of visible light absorption and electron‐hole separation have prompted efforts to enhance their energy utilization and reduce electron‐hole recombination. In our study, we investigated the fabrication of a ternary Ag/g‐C3N4/BiVO4 composite for Rhodamine B (RhB) degradation under visible light irradiation using a combination of photo‐deposition and calcination methods. Our findings demonstrate that the Ag/g‐C3N4/BiVO4 outperforms g‐C3N4, BiVO4, and g‐C3N4/BiVO4 in terms of RhB degradation rate. This improvement can be attributed to the improved light absorption and synergetic effects on charge transfer and photoelectron‐hole recombination resulting from the incorporation of Ag into the ternary system. This ternary Ag/g‐C3N4/BiVO4 composite has potential as a photocatalyst for the removal of organic pollutants due to its reasonable design and superior effectiveness.

Ce-MOF modified Ceria-based photocatalyst for enhancing the photocatalytic performance

Fabricating efficient and stable photocatalysts with an improved photocatalytic property is necessary to decontaminate wastewater. Herein, the [email protected]2 microspheres with a hollow structure are designed and synthesized. The unique hollow structure with the π-π conjugate organic ligand offers abundant reactive sites and a charge transfer channel, both enhancing the performance of photocatalysts. The SEM and TEM tests showed that the [email protected]2 composite retains the hollow microsphere structure, and its diameter is about 600–900 nm. At the same time, the prepared composite showed excellent photocatalytic performance for the degradation of rhodamine B (RhB) under visible-light-driven, within 30 min dark adsorption and 150 min visible light, the degradation rate for RhB reached 95.5% of Ce-MOF/h-CeO2-2 composite, which were 7.17 and 4.46 times of h-CeO2 and Ce-MOF, respectively. Furthermore, the composite of [email protected]2-2 exhibited a remarkable photocatalytic hydrogen evolution efficiency (3419.38 μmol‧g−1‧h−1), which was 15.16 and 10.91 times greater than that of the pure samples. This study provides helpful results of the metal–organic framework that can sensitize effectively the inorganic semiconductor materials for improving photocatalytic performance.

Preparation of Iron Oxalate from Iron Ore and Its Application in Photocatalytic Rhodamine B Degradation

In this study, iron oxalate dihydrate (FOD-ore) was produced from iron ore by the process using oxalic acid to extract iron, followed by photo-reduction. Several techniques, such as X-ray powder diffraction (XRD), Raman, scanning electron microscopy with energy dispersive X-Ray analysis (SEM-EDX), ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL), and X-ray photoelectron spectroscopy (XPS), were used to determine the physicochemical properties of the FOD-ore sample. To compare the photocatalytic activity of FOD-ore, commercial hematite (Fe2O3) was used as a precursor to creating iron oxalate (FOD). The FOD-ore was applied to the photocatalytic degradation of rhodamine B (RhB), a model organic pollutant in wastewater. Using the produced FOD-ore, we were able to degrade more than 85% of RhB within 90 min at a rate approximately 1.4 times higher than that with FOD. FOD-ore demonstrated greater light absorption than FOD, resulting in improved RhB degradation performance. Moreover, the enhanced separation and transport of photogenerated electron-hole pairs can be attributed to the increased photocatalytic RhB degradation rate of FOD-ore, confirmed by photoluminescence results. Therefore, FOD-ore can be utilized as a potential photocatalyst in the degradation process for other organic pollutants under light irradiation.

The preparation of MoS2/δ-FeOOH and degradation of RhB under visible light

MoS2/δ-FeOOH composite catalyst was constructed by a simple solvothermal–coprecipitation method, and the catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance (UV–vis DRS), X-ray photoelectron spectroscopy (XPS) and paramagnetic resonance spectroscopy (EPR). The results of analysis indicated that the composite was successfully prepared, and δ-FeOOH adhered to the surface of spheroidal MoS2 firmly and uniformly, with a particle size of about 1–2 µm. The introduction of co-catalyst MoS2 successfully expanded the photoresponse range of the catalyst, and constructed heterojunction with δ-FeOOH effectively inhibited the photogenerated electron-hole pair recombination. The degradation of organic dye Rhodamine B (RhB) by MoS2/δ-FeOOH activated peroxymonosulfate (PMS) under visible light was studied. The results showed that the degradation rate of RhB was 99.99% within 35 min. The excellent catalytic performance of MoS2/δ-FeOOH can be attributed to the dual-synergy of bimetallic and photocatalysis. In addition, the main active components of the MoS2/δ-FeOOH/PMS/vis system was determined to be 1O2 by free radical quenching experiment and EPR. After 5 cycles of degradation experiments, the removal rate of RhB still reached 89.68%, indicating that the material has good stability and repeatability. The MoS2/δ-FeOOH not only has good photocatalytic activity, but also has strong anti-interference ability for the actual water matrix degradation. Therefore, the MoS2/δ-FeOOH has a excellent application prospect in practical wastewater treatment.