Photocatalytic Removal Of Rhodamine Research Articles

Photocatalytic removal of rhodamine B using a novel g–C3N4–organic solid waste biochar composite: Pathway, key factors, and mechanism

Over the past decades, water pollution caused by organic dyes has attracted extensive attention. The development of efficient, environmental friendly photocatalysts is a promising route for wastewater purification. Herein, a novel wild jujube shell derived biochar/g-C3N4 (BC/CN) composite has been prepared via a one-step calcination route. Although the specific surface area (9.37 m2/g) and pore size (14.57) of the BC/CN composite are smaller than those of g-C3N4, it exhibits enhanced photocatalytic activity. Especially, the 0.25-BC/CN composite (sour jujube shell powder/melamine ratio = 0.25) displays excellent photocatalytic activity, and can degrade ∼97.1 % of RhB under 40 min light irradiation, which is ∼46.51 times to that of pure g-C3N4. The actives species of h+, ·OH, ·O2− and 1O2 active species play the important roles in the photocatalytic system of the BC/CN composite. The results mechanistic study demonstrates that the enhanced photocatalytic activity of the BC/CN composite can be mainly attributed to the improved light absorption and charge separation efficiency of the catalyst. This work provides a simple method for preparing of novel highly efficient g–C3N4–based photocatalyts for wastewater purification, and provides a new idea for the recycling, and high-value utilization of the organic solid waste from traditional Chinese medicine.

Photo-catalytic removal of rhodamine B by nickel doped graphitic carbon nitride: anomalous dependence of removal efficiency on carrier recombination

Photo-catalytic removal of rhodamine B by nickel doped graphitic carbon nitride: anomalous dependence of removal efficiency on carrier recombination

Synergic effect of CuS and MgO for boosting adsorption-photocatalytic activity of S-doped biochar

Adsorption coupled with photocatalysis is a promising route to remove dyes from wastewater. Biochar was modified with S, CuS, and MgO (CuS–Mg/S-BC) through one-pot sulfurization to boost the adsorption and photocatalytic removal of rhodamine B (RhB). The abundant functional groups as well as vacant sites formed at the junction interface among S-doped biochar, CuS, and MgO favored RhB adsorption and photon capture, and this tight interface increased the separation and transfer of photoinduced e−-h+ pairs. Hence, CuS–Mg/S-BC exhibited greater removal efficiency than S-doped biochar, 2-CuS/S-BC (The biochar is loaded with 5 % CuS), and b-Mg/S-BC (The biochar is loaded with 5 % MgO). Langmuir and second-order models well described the adsorption isotherms and kinetics, respectively of CuS–Mg/S-BC composites. 2 b-CuS-Mg/S-BC (Biochar is loaded with both 5 % CuS and MgO) exhibited a removal efficiency of 95.70 % within 120 min, and qe estimated from the second-order model was 981.67 mg g−1. For a 220 mg L−1 RhB solution, the removal efficiency and the adsorption efficiency decreased from 95.70 % to 87.01 % and from 83.54 % to 76.17 %, respectively, after seven cycles.

Improved photocatalytic degradation of rhodamine B by g-C3N4 loaded BiVO4 nanocomposites

Photocatalytic degradation has emerged as one of the most efficient methods to eliminate toxic dyes from wastewater. In this context, graphitic nitride (g-C3N4) loaded BiVO4 nanocomposites (5 wt% g-CN@BiVO4 and 10 wt% g-CN@BiVO4) have been fabricated by the wet impregnation method, and their efficiency towards photocatalytic removal of rhodamine B have been investigated under visible light irradiation. These hybrid composites have been characterized by XRD, FESEM, HRTEM, EDS-mapping, UV-Vis DRS, DLS, XPS and BET, etc. The HRTEM images revealed that BiVO4 has a decagonal shape covered by a layered nanosheet-like structure of g-C3N4. BET measurements suggest increasing the proportion of g-C3N4 results enhancement of the specific surface area. Among different photocatalysts, the 10 wt% g-C3N4@BiVO4 hybrid possesses the best catalytic activity with 86% degradation efficiency after 60 min of reaction time. The LC-MS studies suggest that the degradation reactions follow the de-ethylation pathway. Even after five cycles, the heterostructure shows only a 14% decrease in photocatalytic activity, confirming its stability. As a result, the binary composite can be regarded as a promising catalyst for the degradation of pollutants due to its ease of preparation, high stability and superior catalytic activity.

Analysis of the structural, morphological, and optical properties of Selaginella lepidophylla-mediated ZnO semiconductor nanoparticles and their influence on the photocatalytic removal of Rhodamine B dye

Analysis of the structural, morphological, and optical properties of Selaginella lepidophylla-mediated ZnO semiconductor nanoparticles and their influence on the photocatalytic removal of Rhodamine B dye

Retraction Note to: Synthesis of an efficient, stable and recyclable AgVO3/ZnO nanocomposites with mixed crystalline phases for photocatalytic removal of rhodamine B dye

Retraction Note to: Synthesis of an efficient, stable and recyclable AgVO3/ZnO nanocomposites with mixed crystalline phases for photocatalytic removal of rhodamine B dye

Photocatalytic removal of Rhodamine B in water using g-C3N4/MIL-53(Fe) material under LED visible light with persulfate activation

Photocatalytic removal of Rhodamine B in water using g-C3N4/MIL-53(Fe) material under LED visible light with persulfate activation

Adsorption and photocatalytic removal of Rhodamine B from wastewater using carbon-based materials

The removal of Rhodamine B dyes (RhB) from wastewater, using the conventional water treatment techniques, usually involves some challenging processes. This is challenging because RhB is a highly soluble and persistent dye found in wastewater. Although some efficient physiochemical techniques have been reported, the limitations associated with these technologies, such as the production of secondary wastes in the chemical precipitation process, cannot be overlooked. Photocatalysis, on the other hand, could transform the dye molecules to less toxic or non-toxic final products without the generation of secondary wastes. Therefore, the combined use of photocatalysis and adsorption processes for the removal of RhB from water has been found to be highly efficient. However, the development of materials that possess efficient adsorption and photocatalytic properties remains a major challenge since most of the known materials have a low adsorption capacity and may not be photostable. Carbon-based materials have been used as an efficient material for the removal of RhB from wastewater due to their high adsorption capacity and light-sensitive properties. In this report, the properties, synthesis and use of the carbon-based materials for the removal of RhB from wastewater are discussed in detail. Different factors that affect the removal of RhB dyes from wastewater and the mechanism of photocatalysis and adsorption isotherms are critically reviewed. Furthermore, limitations of carbon-based materials as both adsorbents and photocatalysts are presented, and the possible methods for overcoming these limitations are also investigated.

Adsorptive and Photocatalytic Removal of Rhodamine B Dye from Water by using Copper Ferrite Polyaniline Nanocomposite

Preparation of copper ferrite polyaniline nanocomposite (CF-PANI) and its use for photocatalytic degradation of Rhodamine B dye from aqueous solution has been studied. Copper ferrite (CuFe 2 O 4 ), a magnetic ferrite (spinel) of nano dimension was synthesized by co-precipitation method. Polyaniline nanocomposite of copper ferrite was prepared by in situ polymerization and SEM technique was used for characterization. Adsorption and photo-degradation capacity of prepared nanocomposite was evaluated under different conditions.

Effect of organic capping agents on the optical and photocatalytic activity of mesoporous TiO2 nanoparticles by sol–gel method

In this work, the effect of capping agent effects on the structural, morphological, optical properties and photocatalytic removal of Rhodamine B (RhB) dye has been investigated. TiO2 nanoparticles were synthesized by a simple, fast and eco-friendly sol–gel method, in the presence of various capping agents, including ethylenediamine, polyvinyl alcohol (PVA), ethylene glycol, glucose and valine. The obtained TiO2 nanoparticles have been characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis, high resolution scanning electron microscopy and transmission electron microscopy, UV–visible absorption and photoluminescence (PL) spectroscopy. XRD pattern reveals the polycrystalline nature of TiO2 with anatase structure. The results revealed that the optical absorption band of TiO2 nanoparticles varied by capping agents. PL spectra exhibited visible emissions due to the formation of defects in the band gap region of TiO2 nanoparticles. The photocatalytic degradation of RhB dye by synthesized TiO2 nanoparticles using different capping agents was investigated under UV irradiation and the results demonstrated that TiO2 nanoparticles have appreciable photocatalytic activity for decomposing RhB dye when PVA was used as a capping agent. The results explained that the preparation of TiO2 nanoparticles showed a high efficiency in the removal of organic dyes.

OPTIMIZATION OF PHOTOCATALYTIC ACTIVITY OF Mg/ZnO NANOPARTICLES IN THE REMOVAL OF A MODEL CONTAMINANT USING RESPONSE SURFACE METHODOLOGY

In this study, Mg-doped ZnO nanoparticles with 2% Mg content were synthesized by sol-gel method. The structure and morphology of the nanoparticles were characterized by TEM, BET and UV-Vis absorbance techniques. From TEM image, it was found out that the nanoparticles had uniform size and uniform distribution. BET analysis revealed that in comparison with pure ZnO, Mg 2%/ZnO nanoparticles had a higher specific surface area. Based on UV-Vis absorbance analysis, Mg 2%/ZnO nanoparticles shifted to a lower wavelength (blue-shift), showing a high photocatalytic activity under UV light irradiation. The central composite design under the response surface methodology (RSM) was used for optimization of the photocatalytic removal of Rhodamine B (RhB) with Mg 2%/ZnO nanoparticles. The results showed that there was a good agreement between the predicted data from RSM and the experimental data with a correlation coefficient of 0.9354. The determined optimum values for removal of RhB were as follows: Mg 2%/ZnO nanoparticles dosage of 500 mg L-1, initial RhB concentration of 6 mg L-1, the irradiation time of 6 min, and pH = 8. In order to get more information about photocatalytic activity of the prepared Mg 2%/ZnO nanoparticles, a comparison was made between the photocatalytic activity in this study and that reported by other researchers. The results revealed the synthesized Mg 2%/ZnO nanoparticles had considerable photocatalytic activity.

Facile synthesis of ZnO nanoplates and nanoparticle aggregates for highly efficient photocatalytic degradation of organic dyes

ZnO nanoplates and nanoparticle aggregates with enhanced photocatalytic activity were synthesized using a facile wet chemical approach. Atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results clearly revealed the presence of ZnO nanoplates and nanoparticle aggregates. Photocatalytic removal of rhodamine B, methylene blue and malachite green dyes from water in the presence of synthesized ZnO nanostructures was investigated. ZnO nanoplates showed enhanced photocatalytic activities for degradation of all three dyes in water as compared with ZnO nanoparticle aggregates, which is attributed to the their larger surface area and higher defect concentration leading to enhanced dye adsorption, improved sunlight utilization capability and higher photocatalytic activity of the exposed facets. The tentative mechanisms underlying the formation of ZnO nanoplates and nanoparticle aggregates and their enhanced photocatalytic activity are proposed.

Graphene-based hollow TiO2 composites with enhanced photocatalytic activity for removal of pollutants

Catalytically active graphene-based hollow TiO2 composites(TiO2/RGO) were successfully synthesized via the solvothermal method. Hollow TiO2 microspheres are uniformly dispersed on RGO. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) were used for the characterization of prepared photocatalysts. The mass of GO was optimized in the photocatalytic removal of rhodamine B (RhB) as a model dye pollutants. The results showed that graphene-based hollow TiO2 composites exhibit a significantly enhanced photocatalytic activity in degradation of RhB under either UV or visible light irradiation. The formation of the graphene-based hollow TiO2 composites and the photocatalytic mechanisms under UV and visible light were also discussed.

Preparation of hollow core/shell CeO2@TiO2 with enhanced photocatalytic performance

In this study, hollow core/shell CeO2@TiO2 photocatalysts were prepared via precipitation-co-hydrothermal method. X-ray diffraction, transmission electron microscopy, UV−Vis diffuse reflectance spectroscopy, thermo-gravimetric–differential thermal analysis, and photoluminescence were used for the characterization of prepared photocatalysts. The synthesis variables were optimized in the photocatalytic removal of rhodamine B (rhB) as a model dye pollutants. The results showed that hollow core/shell CeO2@TiO2 exhibit a significantly enhanced photocatalytic activity in degradation of rhB under either UV or visible light irradiation. The formation of the hollow core/shell CeO2@TiO2 and the photocatalytic mechanisms under UV and visible light were also discussed.

Photocatalytic decolorization of Rhodamine B dye using novel mesoporous SnO2–TiO2 nano mixed oxides prepared by sol–gel method

Abstract The photocatalytic removal of Rhodamine B dye was successfully carried under UV irradiation over mesoporous SnO2/TiO2 nanoparticles embedded various molar compositions of SnO2 (0–25%) synthesized by sol–gel process using polymethylmethacrylate as template. Structural and textural features of the samples were investigated by X-ray diffraction (XRD), nitrogen adsorption–desorption isotherm, Fourier transformer infra-red (FTIR) and transmission electron microscope (TEM). The existence of tin oxide is associated with remarkable reduction in particle size to 6 nm and increasing the surface area up to161 m2/g revealing the successful role of SnO2 in manipulating high surface area nanoparticles. The TEM results revealed that well-dispersed and uniform spherical nanoparticles with diameters of 6 nm were embedded in the sample matrix. Both adsorption and UV irradiation are contribute for decolorization of about 92% of Rhodamine dye over the sample embedded 10% SnO2 after 3 h of the reaction compared with 70% only decomposition over pure titania. The photocatalytic decolorization of the dye follows a pseudo-first-order kinetics and the apparent rate constant was increase with increasing the tin oxide content up to 10%. The existence of tin oxide is associated with remarkable reduction in particle size, increasing the oxidizing power and increasing the efficiency of charge carrier separation which considered the main reasons for a remarkable increasing in the catalytic activity of the samples. As the mode of preparation is economically feasible, we can consider this catalyst to be very effective to decolorize various organic dyes.

Effective solar absorption and radial microchannels of SnO2 hierarchical structure for high photocatalytic activity

Photocatalytic removal of rhodamine B (RhB) and methyl orange (MO) has been studied using the hierarchical SnO2 nanoflowers and SnO2 nanorods under the simulated sunlight irradiation to investigate the influence of morphology on the photocatalytic activity. The hierarchical SnO2 nanoflower catalyst shows higher photocatalytic activity compared with SnO2 nanorod catalyst owing to its larger specific surface area and hierarchical structure, which can promote sunlight absorption and provide radial microchannels for reactant diffusion. The experiment also demonstrates a good photostability and reusability of the SnO2 nanoflower catalyst in photocatalystic degradation.