Photo-Assisted Removal of Rhodamine B and Nile Blue Dyes from Water Using CuO-SiO2 Composite

Wastewater from the textile industries contaminates the natural water and affects the aquatic environment, soil fertility and biological ecosystem through discharge of different hazardous effluents. Therefore, it is essential to remove such dissolved toxic materials from water by applying more efficient techniques. We performed a comparative study on the removal of rhodamine B (RhB) and Nile blue (NB) from water through a catalytic/photocatalytic approach while using a CuO-SiO₂ based nanocomposite. The CuO-SiO₂ nanocomposite was synthesized through a sol-gel process using copper nitrate dihydrate and tetraethylorthosilicate as CuO and SiO₂ precursors, respectively, with ammonia solution as the precipitating agent. The synthesized nanocomposites were characterized, for their structure, morphology, crystallinity, stability, surface area, pore size and pore volume, by using a scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) techniques. The CuO-SiO₂ nanocomposite was used for potential environmental applications in the terms of its catalytic and photocatalytic activities toward the degradation of rhodamine B (RhB) and Nile blue (NB) dyes, in the presence and absence of light, while monitoring the degradation process of dyes by UV-Visible spectroscopy. The catalytic efficiency of the same composite was studied and discussed in terms of changes in the chemical structures of dyes and other experimental conditions, such as the presence and absence of light. Moreover, the composite showed 85% and 90% efficiency towards the removal of rhodamine B and Nile blue dyes respectively. Thus, the CuO-SiO₂ nanocomposite showed better efficiency toward removal of Nile blue as compared to rhodamine B dye while keeping other experimental variables constant. This can be attributed to the structure-property relationships and compatibility of a catalyst with the molecular structures of dyes.

Facile fabrication of green nano pure CeO2 and Mn-decorated CeO2 with Cassia angustifolia seed extract in water refinement by optimal photodegradation kinetics of malachite green

To eradicate the aquatic pollution caused by dyes, trendily the global researchers provide dedication to dye degradation using nanostructured photocatalyst. This research work is dedicated to explore an advanced, facile, bio-compact green fabricated nanostructure for water refinement. In this regard, plant-mediated syntheses of pure CeO₂ and Mn-decorated CeO₂ nano-powders have been inspected using seed extract of Cassia angustifolia. Investigations through UV-diffuse reflectance spectroscopy explored the significantly tuned band gap of Mn:CeO₂. FT-IR spectroscopy shows the existing functional groups of high-potential phenolic compounds, proteins, and amino acids in Cassia angustifolia act as reducing and capping agents involved in the green fabricated nanostructured samples. X-ray diffraction pattern has been exposed to crystalline cubic fluorite morphology in a single phase and it leads to a regulated optimized amount of Mn on CeO₂ nanostructure. The FESEM analysis predicts the morphology of CeO₂ in spherical and Mn:CeO₂ in flower-like structure. The HRTEM analysis has portrayed particle size of CeO₂ is 11 nm and tuned Mn:CeO₂ nanostructure is 9 nm. The HRTEM images revealed the average particle size in the range 10-12 nm in CeO₂ and 8-9 nm in 5 mol% Mn:CeO₂ nanoparticles. It showed a decrease in average particle size with an increase in Mn concentration and the reduction in size may be due to the replacement of Ce(IV) with Mn(II) ions. The elemental composition in nanostructure was predicted using energy-dispersive X-ray analysis. The rapid photocatalytic degradation efficiency of malachite green was effectually performed and compared with the kinetics model of Mn:CeO₂ and pure CeO₂ nanostructures. From the augmented results, tuned Mn:CeO₂ was found to act as the finest green fabricated photocatalyst in the amputation of lethal and carcinogenic dye.

Synthesis and characterization of heterostructured nanoparticle for efficient photocatalytic performance for dye degradation

This paper focusses on the synthesis of cobalt vanadate (CoVO4) nanoparticles (NPs) by precipitation method. This was further augmented by assistance from microwave. Nanotechnology has been a wonderful tool with the promising application in different fields of life. The CoVO4 NPs synthesized by microwave assisted precipitation method was characterized by advanced techniques such as X-ray powder diffraction (XRD), Energy dispersive X-ray analysis (EDX), Scanning electron microscopy (SEM), Ultraviolet visible spectroscopy (UV–vis) techniques. Rhodamine B (RhB) dye was used to evaluate the photo catalytic activity (PCA) of NPs by degradation of dye. The conditions were optimized for maximum degradation of dye. The NPs were in the nano flowers form and the size was ≤100 nm. The results regarding degradation of RhB was through PCA were promising; 83% dye was degraded at pH 10, reaction time 160 min and catalyst dose 1 g. It may conclude that the synthesized NPs could further be employed for possible treatment of industrial effluents particularly textile industry.

Photocatalytic Performance and Degradation Pathway of Rhodamine B with TS-1/C3N4 Composite under Visible Light

TS-1/C3N4 composites were prepared by calcining the precursors with cooling crystallization method and were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), UV-Vis diffuse reflection spectrum (DRS) and nitrogen adsorption-desorption isotherm. The photocatalytic performance of TS-1/C3N4 composites was investigated to degrade Rhodamine B (RhB) under visible light irradiation. The results showed that all composites exhibited better photocatalytic performance than pristine TS-1 and C3N4; TS-1/C3N4-B composite (the measured mass ratio of TS-1 to C3N4 is 1:4) had best performance, with a rate constant of 0.04166 min-1, which is about two and ten times higher than those of C3N4 and TS-1, respectively. We attributed the enhanced photocatalytic performance of TC-B to the optimized heterostructure formed by TS-1 and C3N4 with proper proportion. From the results of photoluminescence spectra (PL) and the enhanced photocurrent, it is concluded that photogenerated electrons and holes were separated more effectively in TS-1/C3N4 composites. The contribution of the three main active species for photocatalytic degradation followed a decreasing order of ·O2-, ·OH and h+. The degradation products of RhB were identified by liquid chromatography tandem mass spectrometry (LC-MS/MS), and the possible photocatalytic degradation pathways were proposed.

Synthesis of a high-surface area V2O5/TiO2–SiO2 catalyst and its application in the visible light photocatalytic degradation of methylene blue

In the present study, we synthesized several high-surface area V₂O₅/TiO₂–SiO₂ catalysts (vanado titanium silicate, VTS). The synthesized materials are characterized by PXRD, FE-SEM/EDAX, TEM, BET-surface area, FT-IR, UV-Vis, XPS, fluorescence and photocatalytic studies.

Synthesis of Bi3TaO7–Bi4TaO8Br composites in ambient air and their high photocatalytic activity upon metal loading

Cocatalyst loading on ambient-air synthesized Bi₃TaO₇–Bi₄TaO₈X (X = Cl, Br) composites for highly suppressed exciton recombination and efficient solar light harvesting.