Photocatalytic Degradation Of Rhodamine B Research Articles

Nitrogen-doped carbon quantum dot as electron acceptor anchored on graphitic carbon nitride nanosheet for improving rhodamine B degradation

Carbon quantum dots (CQDs) hold significant promise for wastewater treatment because of their remarkable attributes, including robust stability, outstanding biocompatibility, minimal toxicity, superior water dispersibility, cost-effective production, and exceptional photo-stability.In this study, CQDs were synthesized using microplasma and tested for the degradation of rhodamine B (RhB) (5 mg/L) under different conditions, with a Solar simulator and UVA illumination. Specifically, graphitic carbon nitride nanosheets (NCN) in conjugation with carbon quantum dots (NCN@CQD) were prepared with different amounts of CQD. The synthesized CQD, NCN, and NCN@CQD underwent characterization using various compositional and structural analytical techniques. The results show that nitrogen species were effectively incorporated into the CQDs framework and CQDs are anchored on NCN forming NCN@CQD successfully. Subsequently, all samples were then investigated in degrading Rhodamin B, RhB, to assess the photocatalytic activity. The results reveal that the presence of CQDs substantially improved the photocatalytic efficiency of NCN. Specifically, the CQDs anchored on NCN exhibited a substantial enhancement in the photoactivity for RhB decomposition under a solar light simulator, surpassing that of pure NCN. The amount of CQD in the NCN@CQD sample exerted a strong influence on the photocatalytic activity. All NCN@CQD samples exhibited remarkable enhancements in both adsorption and photocatalytic performance compared to pure CQD and NCN samples. In an optimization study, a best NCN@CQ photocatalyst was identified, showing a 40 % enhancement of photocatalytic efficiency compared to the use of NCN alone. A visible light photocatalytic activity of 91 % can be attained within 150 min, exhibiting a reaction rate constant of 0.0135 min−1 toward RhB decomposition, which was double as for the individual NCN (0.0067 min−1). The boosted photocatalytic activity resulting from the synergistic effect between NCNs and CQDs can be attributed to the efficient function of CQD as an electron acceptor. The proposed mechanism of photocatalytic degradation of RhB is illustrated in detail.

Regulation of Lewis acid sites on ZnO/SiW11Co for tunable photocatalytic activity toward water remediation

The function of surface acidity in catalytic reactions has been well studied in the field of conventional catalysis, nevertheless, regulating surface acidic sites and unveiling its roles during heterogeneous photocatalysis has been less frequently reported. To address this issue, we constructed a novel heterojunction photocatalyst of ZnO/SiW11Co with abundant Lewis acid sites for wastewater treatment. Under visible light irradiation, the optimal ZnO/SiW11Co was found to have the highest photocatalytic activity, achieving a degradation efficiency of 97.7% for Rhodamine B (RhB), 96.1% for tetracycline (TC), and 91.4% for methyl orange (MO). The RhB removal rate remained at 91.3% even after five cycles, indicating excellent stability and practicality of ZnO/SiW11Co. By compositing with SiW11Co, a typical polyoxometalates with unique super acid properties, ZnO/SiW11Co formed plentiful surface Lewis acid sites, as confirmed by the pyridine adsorption FT-IR and NH3-TPD. The as-formed Lewis acid sites could provide more active sites, making it easier for reactants to coordinate to the photocatalyst surface, which reduced the activation energy of photocatalytic reactions and accelerate RhB removal. Density functional theory (DFT) calculations unveiled the redistribution of electron-hole pairs, optimizing the light absorption and charge separation efficiency, which obeyed a Z-scheme mechanism. Combined active species capture experiments and electron spin resonance, •O2−, h+, and •OH were the main active substances for the photocatalytic degradation of RhB. Besides, the possible degradation pathways for RhB were analyzed using liquid chromatography-mass spectrometry (LC-MS). The work provided useful strategy for the design of high-performance photocatalysts via regulating surface Lewis acid sites toward water remediation.

Enhanced photocatalytic performance of Ga2O3 hollow spheres prepared by hard template technique

Semiconductor-assisted photocatalytic treatment has been regarded as a promising technique to dispose the dye-contaminated wastewater and gained pronounced attention recently. Here, we demonstrated a kind of Ga2O3 nanometer hollow sphere photocatalysis by template-assisted technique and applied it on the degradation of Rhodamine B (RhB). It was found that the hollow spherical structure of photocatalyst can greatly enhance the photo absorption and reduce the recombination of photogenerated carriers, thus improve the photocatalytic performance. This study provides a new method for efficient photocatalytic degradation of RhB, and provides a new idea for subsequent degradation work.

Enhanced Visible Light Photocatalytic Activity of Exfoliated Boron‐TiO2 Composite for Degradation of Rhodamine B and Nitrogen Fixation

AbstractThe design of an efficient, recyclable, visible light photocatalytic system was examined as a viable new green way to address environmental challenges such as removal of pollutants from wastewater and N2 fixation. The exfoliated boron (Bexf)‐Titanium oxide (TiO2) composite visible light active photocatalysts were successfully constructed via a simple wet chemical method by utilizing acetone as a solvent. The composite was evaluated for the photodegradation of Rhodamine B (RhB) dye and reduction of N2, which exhibits improved photocatalytic activity for degradation of RhB as well as for reduction of N2. Experiments with different quenchers indicate that the photogenerated superoxide radical anion (O2⋅−) plays a significant role in the degradation of RhB as well as for N2 reduction reactions. The composite catalyst shows good photostability and there is no significant reduction of the catalyst activity for dye degradation up to 4 cycles of reaction. This work affords a significant view into the design of reusable TiO2 composite materials for photocatalytic RhB degradation and nitrogen fixation.

Photocatalytic Degradation of Rhodamine-B and Water Densification via Eco-Friendly Synthesized Cr2O3 and Ag@Cr2O3 Using Garlic Peel Aqueous Extract

The purification and densification of wastewater play an important role in water recycling, especially if the materials used in water recycling are other types of recycled waste. Therefore, considering this view in this study, the biosynthesis of silver-decorated chromium oxide nanoparticles utilizing a wasted Allium sativum (garlic) peel extract is investigated. The aqueous extract of garlic peel (GPE) was treated with silver nitrate, chromium nitrate, and a mixture of silver nitrate and chromium nitrate to synthesize silver nanoparticles (Ag-garlic), chromium oxide nanoparticles (Cr2O3-garlic), and silver-decorated chromium oxide nanoparticles (Ag@Cr2O3-garlic), respectively. The synthesized nanoparticles were elucidated via thermal gravimetric analysis (TGA), infrared spectra (FT-IR), absorption spectra (UV-Vis), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Antimicrobial activity studies were conducted against waterborne germs, bacterial strains (Bacillus subtilis, Enterococcus faecium, Escherichia coli, and Pseudomonas aeruginosa), and fungal strains (Alternaria porri, Aspergillus flavus, Aspergillus niger, Fuserium oxysporum, and Trichoderma longibrachiatum) and showed significant levels of antimicrobial activity. The results revealed that Ag@Cr2O3 significantly improved antimicrobial activity due to their synergistic effect. The photocatalytic activity of nanoparticles was assessed using Rhodamine B dye (5 ppm) under solar irradiation. Cr2O3-garlic exhibited the best activity as a photocatalyst among the studied nanoparticles, with 97.5% degradation efficiency under optimal conditions.

Morphological regulation of CdS/Ga0.04Cd0.96S nanocomposites for enhanced efficiency of solar-driven rhodamine B degradation

In recent years, semiconductor-based nanocomposites have emerged as promising materials for solar-driven photocatalytic degradation of organic pollutants. In this study, GaxCd1−xS nanospheres were successfully synthesized through the interstitial doping of Ga ions into CdS nanospheres via a hydrothermal route. These nanospheres were further employed to create CdS NRs/Ga0.04Cd0.96S nanocomposites using solvothermal methods, aiming to enhance the efficiency of solar-driven rhodamine B (Rh-B) degradation. The photocatalytic activities of the prepared CdS nanostructures, Ga0.04Cd0.96S nanospheres, and CdSNRs/Ga0.04Cd0.96S nanocomposites were evaluated for dye removal and photocatalytic degradation. Notably, Ga0.04Cd0.96S (1:30) nanospheres exhibited high efficiency in degrading Rh-B compared to pure CdS nanostructures under identical reaction conditions. Single CdS NRs/Ga0.04Cd0.96S (1:1) demonstrated stable cyclic photocatalytic performance over multiple rounds of use. The study further elucidated the enhanced separation and lower recombination of photogenerated electrons and holes in CdS NRs/Ga0.04Cd0.96S compared to Ga0.04Cd0.96S, as confirmed by PL spectrum and photocurrent response studies. The scavenger method was employed to identify reactive species, providing insights into the mechanism of Rh-B degradation. Additionally, the proposed mechanism of photocatalytic degradation of Rh-B over the CdS NRs/Ga0.04Cd0.96S nanocomposites was discussed. This research contributes valuable insights into the development of efficient semiconductor-based nanocomposites for solar-driven photocatalysis, addressing environmental concerns related to organic pollutant degradation.

Aminated graphene quantum dots/CdS nanobelts for enhanced photocatalytic degradation of RhB dye under visible light.

CdS nanoparticles have wide applications as photocatalysts for degradation of organic pollutants, but due to their limited turnover number and off-pathway charge recombination processes, their degradation efficiency is low. Herein, aminated graphene quantum dots/CdS (GQDs/CdS) nanobelts were successfully fabricated by solvothermal and hydrothermal processes. The prepared GQDs/CdS were characterized by physical methods to investigate their structure, morphology, optical properties, specific surface area, element composition, and chemical state. GQDs/CdS materials promoted efficient charge separation, and showed high efficiency in the photocatalytic degradation of the organic dye Rhodamine B (RhB) under visible light. The degradation efficiency of RhB samples over 0.05 g of catalysts reached 97.40% after 150 min, a much higher efficiency in comparison to pure CdS. Electron paramagnetic resonance (EPR) spectroscopy provided direct evidence for ˙OH and ˙O2- as the reactive oxidative species using DMPO as a spin trap. Consistent with the experimental results, a possible mechanism of RhB photocatalytic degradation by GQDs/CdS under visible light was proposed. This work may provide environmentally friendly photocatalysts for degrading organic dyes and purifying water.

Activation of peroxymonosulfate by halloysite nanotube-supported TiO2 composite for efficient photocatalytic degradation of Rhodamine B

In this study, to enhance the peroxymonosulfate (PMS)-assisted photocatalytic degradation of Rhodamine B (RhB) under visible light over TiO2, a novel halloysite nanotube (HNTs) supported TiO2 composite photocatalyst was prepared by the sol-gel method. The crystal structure and bonding information of samples were investigated by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible diffuse reflection spectroscopy (DRS), photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) were used to characterize the morphology, optical properties and energy band structure of the samples. The composite with weight ratio of 1:5 (HNTs/TiO2) (named HT-20) exhibited apparently enhanced PMS-assisted photocatalytic RhB degradation efficiency and can degrade approximately 95.31 % of RhB in 30 min, and the first-order rate constants (k) of HT-20-PMS system is about 54.5 times higher than that of B–TiO2. In addition, the possible mechanism of enhanced PMS-assisted photocatalytic activity of HT-20 was proposed. The improvement of photocatalytic activity in the composite photocatalyst can be ascribed to the large surface area and strong adsorption capacity of HNTs.

Enhancing O2 adsorption and activation over porous S-doped g-C3N4 rod toward efficient photocatalytic rhodamine-B degradation

Photocatalytic oxygen molecular (O2) activation to generate reactive oxygen species (ROS) is a promising strategy for the oxidative degradation of organic pollutants. Herein, a porous S-doped g-C3N4 rod (S-g-CN-rod) was synthesized and applied to photocatalytic superoxide radicals (·O2-) evolution and rhodamine-B (RhB) degradation. The morphological, structural, and optical properties of all samples were investigated. DFT calculation demonstrated that the carbon site adjacent to S was energetically favorable for O2 adsorption, which was conducive to ·O2- evolution. The porous S-g-CN-rod exhibited an excellent photocatalytic ·O2- evolution rate of 268.2 μmol L−1 h−1, which was the main active species to degrade RhB. Conceivably, the porous S-g-CN-rod demonstrated exceptionally high efficiency of photocatalytic RhB degradation and achieved almost complete disposal of RhB (99.7 %) in only 30 min, which was higher than most reported photocatalysts. The experimental results and theoretical calculations demonstrated that the preeminent photocatalytic activities were ascribed to enhanced light-harvesting, improved migration and separation of photo-induced electrons, and the superior O2 adsorption and activation induced by S doping.

Cu and Fe doped NiCo2O4/g-C3N4 nanocomposite ferroelectric, magnetic, dielectric and optical properties: Visible light-driven photocatalytic degradation of RhB and CR dyes

A novel Cu and Fe doped NiCo2O4/g-C3N4 nanocomposites were prepared with varying dopant concentrations via a precipitation and ultrasonication route. The resulting Ni1-xCuxCo2-yFeyO4/g-C3N4 nanocomposites were characterized by advanced techniques and effect of doping was investigated based on ferroelectric, dielectric, magnetic, electrical, optical and photocatalytic properties. The results confirmed the FCC spinel geometry of NiCo2O4 nanoparticles with a spherical shape (ranging from 18 to 32 nm). The absorption range in the visible region and the suppression of electron-hole recombination were investigated through UV–Vis diffused reflectance spectra and PL analysis. The Cu and Fe doping significantly influenced the dielectric properties and the AC conductivity of Ni1-xCuxCo2-yFeyO4/g-C3N4 nanocomposites was also increased with Cu and Fe substitution. The photocatalytic activity of doped Ni0.75Cu0.25Co1.5Fe0.25O4/g-C3N4 (NCCF3/g-CN) were evaluated for the removal of rhodamine B (RhB) and Congo red dyes under visible light irradiation. The NCCF3/gCN nanocomposite exhibited the dye removal of 89 % versus undoped nanocomposite (50 %). The rate constants for CR dye degradation were found to be 0.04366 and 0.1009 (min−1) for the NCCF3/gCN nanocomposite and undoped nanocomposite NiCo2O4/gC3N4 (NCO/gCN), respectively. The efficient separation of charge carriers was facilitated by the migration of photo-induced electrons from the g-C3N4 surface to the NiCo2O4. The influence of pH and catalyst dose on the kinetics of photocatalytic activity revealed a significant effect on the dye degradation rate. The results indicate that the NiCo2O4/g-C3N4 shows a promising potential for photocatalytic removal of dyes under visible light illumination, which could be employed for the removal of dyes from the effluents.

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.

Evaluation of MnO2 incorporated cellulose acetate membranes and their potential photocatalytic studies using Rhodamine-B dye

In this study, CA/MnO2 nanocomposites were successfully synthesized by using a magnetic stirring method that was not prohibitively expensive. For the purpose of characterizing nanocomposites, XRD, EDX, Photoluminescence, FTIR, and XPS were used. FESEM was used to observe the shape and dimensions of the formed CA/MnO2 nanocomposites. For the purpose of evaluating CA/MnO2 nanocomposites, photocatalytic degradation of rhodamine-B that was obtained from the dyeing industry was employed. In addition, research was conducted on the photocatalytic process of rhodamine-B degradation in an aqueous solution. This method displayed that the concentration of rhodamine-B decreased by 81 % in only sixty minutes when it was exposed to UV–visible light. These results pave the way towards developing more efficient visible-light-responsive photocatalysts to remove organic pollutants during the water treatment process.

The Wood/MoS2 Composites with Good Adsorption and Photocatalytic Ability for Highly Efficient Removal of Organic Dye Molecules

AbstractOrganic dye‐contained wastewater is a major threat to the global environment and public health. In this study, natural wood and MoS2 are combined to create effective photocatalysts for removing organic pollutants from water under light irradiation. The results show that the photocatalytic degradation activity of wood/MoS2 composites are obviously superior to that of natural wood under solar light as well as possess outstanding stability after three reaction cycles. The improvement in photocatalytic performance for photodegradation is primarily due to an increase in specific surface area and the introduction of catalytic active sites from the edge S, which favors adsorption of organic pollutants and accelerates the degradation process. The synergistic effect of adsorption and photocatalysis also ensures that the composited catalyst is highly universal in its application to organic dye degradation, including RhB (Rhodamine B), MB (Methylene Blue), and MO (Methyl Orange); the kinetic constant for the photocatalytic degradation of RhB, MO, and MB are 0.040, 0.035, and 0.032 min−1, respectively and the degradation performance can be well maintained after three cycle tests. Our study has proved that the wood/MoS2 composite is a novel, low‐cost photocatalyst that plays an important role in environmental protection.

Fabrication of LaFeO3-nitrogen deficient g-C3N4 composite for enhanced the photocatalytic degradation of RhB under sunlight irradiation

LaFeO3-nitrogen deficient g-C3N4 (LaFeO3-g-C3N4-H) heterostructure has been fabricated obtaining thermal polymerization of acetic acid-treated melamine followed by incorporation of perovskite-type LaFeO3 onto the graphitic carbon nitride nanosheets (g-C3N4) using La(NO3)3·6H2O and Fe(NO3)3·9H2O as precursors. The as-synthesized nanocomposite was investigated using Fourier Transform Infrared Spectroscopy (FT-IR), powder X-ray diffraction (XRD), UV–Vis Diffuse Reflection Spectroscopy (UV–Vis DRS), Scanning Electron microscope (SEM), and Transmission Electron microscope (TEM). The findings of the characterization study revealed the successful incorporation of LaFeO3 on g-C3N4-H nanosheets. The band gap energy of LaFeO3-g-C3N4-H heterojunctions was found to be active in the visible light region. The LaFeO3-g-C3N4-H ability to degrade Rhodamine B (RhB) dye in an aqueous solution was investigated under sunlight illumination. The results of photocatalytic degradation activity showed that LaFeO3-g-C3N4-H photocatalyst haspresented the highest photocatalytic efficiency of 99.5% after 60 min under sunlight irradiation. The remarkable photocatalytic activity can be attributed to the defect structure of g-C3N4 and the construction of heterojunction. In addition, LaFeO3-g-C3N4-H showed promise recyclability after 5 cycles with slight activity reduction.

Optimization of photocatalytic degradation performance of organic dye using highly efficient bismuth MOFs: Preparation and parametric analysis

Bismuth MOF catalysts were successfully fabricated using the solvothermal method, which involved the use of a mixed solvent composed of DMF and ethanol in varying volume ratios. Subsequently, the catalysts underwent comprehensive characterization using diverse techniques i.e., FTIR, XRD, N2 adsorption-desorption, UV–vis diffuse, and SEM-EDX. The photocatalytic degradation of RhB was investigated using six different bismuth MOF (BiEt) catalysts. Later, parametric analysis study was performed to test the BiEt catalysts under different values of pH, Rhodamine B (RhB) dye concentrations, and different scavengers. The results showed that BiEt1 had total surface area of 16.78 m2/g and pore volume of 0.025 cm3/g with a pore size of 1.5331 nm. The photocatalytic performance of the catalysts was assessed by quantifying the removal capacity and analyzing theUV–vis absorption spectra during the degradation of RhB. The results show that BiEt 1 had the highest photodegradation efficiency toward the RhB and that it required the shortest time of 60 min to achieve 100% removal. The UV–vis absorption spectra of BiEt catalysts during the degradation of RhB showed that the characteristic absorption wavelength of RhB was observed at 576 nm. These findings suggest that the prepared BiEt was an exceptional photocatalyst for the degradation of RhB. It has great potential for environmental remediation applications.

An efficient biosynthesis of novel ZnO/CuO nanocomposites using berberis vulgaris extract (ZnO/CuO@BVENCs) for enhanced photocatalytic degradation of pollution, antibacterial and antifungal activity

In this study, an environmentally-friendly method was employed to synthesize ZnO/CuO nanocomposites using berberis vulgaris extract, resulting in ZnO/CuO@BVE NCs. The structure and properties of the ZnO/CuO@BVE NCs were characterized using various analytical techniques including XRD, UV-DRS, FESEM, FT-IR, EDAX, and TEM. UV-DRS results highlighted a bandgap energy reduction from 3.11 eV to 2.93 eV due to CuO integration with ZnO. TEM images confirmed the nanocomposite size to be between 35–50 nm. To evaluate the photocatalytic effectiveness of the biosynthesized nanocomposites, rhodamine b (RhB) was used as a representative contaminant. We thoroughly investigated the influence of multiple variables such as dye concentration, nanocatalyst amount, light source, and pH on the photocatalytic degradation of RhB. Under optimized conditions (0.15 g/L nanocatalyst, pH 11, UV light, and 3 ppm pollutant concentration), a remarkable 97.3% RhB degradation efficiency was achieved. Additionally, the antibacterial properties of the ZnO/CuO@BVE NCs were tested against six ATCC strains. Notably, they exhibited strong antibacterial action, especially against K. pneumoniae and P. aeruginosa, with a minimum inhibitory concentration (MIC) as low as 62.5 μg/mL. Furthermore, the nanocomposites demonstrated significant antifungal activity against C. albicans with an MIC of 31.2μg/mL. This research emphasizes the potential applications of ZnO/CuO@BVE NCs in environmental remediation and medical fields.

Facile Construction of 2D/2D ZnIn2S4-Based Bifunctional Photocatalysts for H2 Production and Simultaneous Degradation of Rhodamine B and Tetracycline.

A two-dimensional/two-dimensional (2D/2D) TiO2/ZnIn2S4 photocatalyst was reasonably proposed and constructed by a two-step oil bath-hydrothermal method. TiO2 nanosheets uniformly grown on the surface of ZnIn2S4 nanosheets and a synergetic effect between the TiO2 and ZnIn2S4 could highly contribute to improving the specific surface area and hydrophilicity of ZnIn2S4 as well as accelerating the separation and transfer of photon-generated e--h+ pairs, and thus enhancing the visible-light photocatalytic degradation and H2 evolution performance of ZnIn2S4. Rhodamine B (RhB) and tetracycline (TC) were simultaneously selected as the target pollutants for degradation in the work. The optimum photocatalytic RhB and TC degradation properties of TiO2/ZnIn2S4-10 wt% were almost 3.11- and 8.61-fold higher than that of pure ZnIn2S4, separately, while the highest photocatalytic hydrogen evolution rate was also observed in the presence of TiO2/ZnIn2S4-10wt% and 4.28-fold higher than that of ZnIn2S4. Moreover, the possible photocatalytic mechanisms for enhanced visible-light photocatalytic degradation and H2 evolution were investigated and proposed in detail. Our research results open an easy pathway for developing efficient bifunctional photocatalysts.

Cost-effective synthesis of highly-dispersed WS2 nanosheets assembled on tourmaline for improved photocatalytic activity

Tungsten disulfide (WS2) has attracted much attention in photocatalysis due to the excellent visible light harvesting and charge transfer kinetics, yet practical applications have been severely limited by the restacking property. In this work, a novel WS2/tourmaline composite was fabricated by coupling hydrothermal and calcination methods. The highly dispersed WS2 nanosheets homogeneously deposited on the tourmaline surface were revealed by electron microscopy, with sufficient exposure of the photocatalytic sites to enhance the migration efficiency of interfacial electrons. The armadillo-like WS2/tourmaline composite exhibited excellent photocatalytic activity for rhodamine B (RhB), with a degradation efficiency of 89.4 % after 150 min irradiation, while only 30.4 % was achieved by the pure WS2 microspheres. Electron paramagnetic resonance and density functional theory (DFT) calculations showed that the WS2/tourmaline composites with more sulfur vacancies preferred to produce sufficient reactive species for photocatalytic RhB degradation. In addition, photogenerated holes (h+) play a more important role in the degradation process of RhB than superoxide radicals (·O2–) and hydroxyl radicals (·OH), as confirmed by radical quenching experiments. This work presents a new option for the low-cost preparation of high-performance 2D materials via mineral assembly.

Enhancement of Photocatalytic Rhodamine B Degradation over Magnesium–Manganese Baring Extracted Iron Oxalate from Converter Slag

In this work, iron oxalate from converter slag (FeOX-Slag) was produced by extraction of iron from converter slag using oxalic acid, followed by photo-reduction. The FeOX-Slag sample was subjected to various characterization techniques, including X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL), X-ray absorption near-edge structure spectroscopy (XANES), and X-ray photoelectron spectroscopy (XPS), in order to gain insights into its physicochemical properties. Also, to compare the photocatalytic activity of the FeOX-Slag, commercial iron oxide (Fe2O3) was used as a precursor to produce normal iron oxalate (FeOX-Fe2O3). The obtained FeOX-Slag was applied to the photocatalytic degradation of rhodamine B (RhB), a model organic contaminant in wastewater, compared with the FeOX-Fe2O3. Using the produced FeOX-Slag, we were able to degrade RhB more than 98% within 90 min at a reaction rate constant of about 3.6 times faster than FeOX-Fe2O3. Photoluminescence results confirmed the less recombination of the electron–hole pairs in FeOX-Slag, compared to FeOX-Fe2O3, which may be due to the defect structure of iron oxalate by guest metal impurities. The higher separation and transportation of photogenerated electron–hole pairs cause the enhancement of the degradation photocatalytic RhB degradation activity of the FeOX-Slag. In addition, The FeOX-Slag showed higher light absorption ability than FeOX-Fe2O3, resulting in the enhancement of the RhB degradation performance. Thus, the optical properties and the results from the activity tests led to the proposal that FeOX-Slag may be used in a photocatalytic degradation process for RhB under light irradiation.

Preparation of C60 Fullerene Nanowhisker–CuS Nanoparticle Composites and Photocatalyst for Rhodamine B Degradation under Blue Light Emitting Diode Irradiation

The liquid-liquid interfacial precipitation (LLIP) approach was used to synthesize the C60 fullerene nanowhisker (FNW)–CuS nanoparticle composites utilizing a CuS nanoparticle solution, C60-saturated toluene, and isopropyl alcohol (IPA). Powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the product of C60 FNW–CuS nanoparticle composites. These were also utilized to photocatalytic degradation of rhodamine B (RhB) under blue light emitting diode (LED) irradiation at 450 nm. Also, UV–vis spectroscopy was used to confirm the photocatalytic degradation activity of RhB over the C60 FNW–CuS nanoparticle composites. The percentage of photocatalytic degradation of RhB was shown to be 95.148%. The kinetics study for photocatalytic degradation of RhB using C60 FNW–CuS nanoparticle composites followed a pseudo-first-order reaction rate law. C60 FNW–CuS nanoparticle composites as photocatalyst have a rate constant of 4.82×10-2 min-1 at 25 °C.