Investigation of pure and g-C3N4 loaded CdWO4 photocatalytic activity on reducing toxic pollutants

Efficiency and mechanistic insights of photocatalytic decomposition of tetracycline and rhodamine B utilizing Z-scheme g-C3N4/SnWO4 heterostructures under visible light irradiation

The hydrothermal approach was used in the design and construction of the SnWO4 (SW) nanoplates anchored g-C3N4 (gCN) nanosheet heterostructures. Morphology, optical characteristics, and phase identification were investigated. The heterostructure architect construction and successful interface interaction were validated by the physicochemical characteristics. The test materials were used as a photocatalyst in the presence of visible light to break down the antibiotic tetracycline (TC) and the organic Rhodamine B (RhB). The best photocatalytic degradation efficiency of TC (97%) and RhB (98%) pollutants was demonstrated by the optimized 15 mg of gCNSW-7.5 in 72 and 48 min, respectively, at higher rate constants of 0.0409 and 0.0772 min-1. The interface contact between gCN and SW, which successfully enhanced charge transfer and restricted recombination rate in the photocatalyst, is responsible for the enhanced performance of the gCNSW heterostructure photocatalyst. In addition, the gCNSW heterostructure photocatalyst demonstrated exceptional stability and reusability over the course of four successive testing cycles, highlighting its durable and dependable function. Superoxide radicals and holes were shown to be key players in the degradation of contaminants through scavenger studies. The charge transfer mechanism in the heterostructure is identified as Z-scheme mode with the help of UV-vis DRS analysis. Attributed to its unique structural features, and effective separation of charge carriers, the Z-scheme gCNSW-7.5 heterostructure photocatalyst exhibits significant promise as an exceptionally efficient catalyst for the degradation of pollutants. This positions it as a prospective material with considerable potential across various environmental applications.

Promoting a well-dispersion of MoO3 nanoparticles on fibrous silica catalyst via one-pot synthesis for enhanced photoredox environmental pollutants efficiency

The coexistence of pharmaceutical compounds and heavy metals in the aquatic environment has resulted in complications in the treatment process and thus, causing uproar among the citizens. The radical-based photocatalysis technology has aroused as an excellent method to eliminate both heavy metal and pharmaceutical compounds in the water. Herein, reported the utilization of the microemulsion technique for the preparation of nanoporous fibrous silica-molybdenum oxide (FSMo) towards simultaneous photocatalytic abatement of hexavalent chromium (Cr(VI)) and tetracycline (TC). The FESEM analysis showed the spherical morphology of the FSMo catalyst with dendrimeric silica fiber. The synthesized FSMo catalyst exhibited narrowed bandgap, high crystallinity, and well Mo element dispersion for enhanced photo-redox of Cr(VI) and TC. Remarkably, simultaneous remediation of the Cr(VI) and TC over FSMo demonstrated superior photocatalytic efficiency, 69% and 75%, respectively, than in the individual system, possibly due to the effective separation of photoinduced charges. The introduction of the Mo element to the silica framework via microemulsion technique demonstrated better dispersion of Mo compared to the incipient wetness impregnation method and thus, yielded higher photocatalytic activity towards simultaneous removal of TC and Cr(VI). Besides, quenching experiments revealed the electrons and holes as the active species that play a dominant role in the simultaneous photo-redox of Cr(VI) and TC. Lastly, the FSMo catalyst demonstrated high stability after four continuous cycles of simultaneous photocatalysis reactions, implying its potential as a suitable material for practical wastewater treatments.

Sono-Photocatalytic Activity of Cloisite 30B/ZnO/Ag2O Nanocomposite for the Simultaneous Degradation of Crystal Violet and Methylene Blue Dyes in Aqueous Media

A new nanocomposite based on Cloisite 30B clay modified with ZnO and Ag₂O nanoparticles (Cloisite 30B/ZnO/Ag₂O) was synthesized as an effective catalyst in the sono-photocatalytic process of crystal violet (CV) and methylene blue (MB) dyes simultaneously. The characteristics and catalytic activity of Cloisite 30B/ZnO/Ag₂O nanocomposite were investigated under different conditions. The specific active surface for Cloisite 30B/ZnO/Ag₂O nanocomposite was 18.29 m²/g. Additionally, the catalytic activity showed that Cloisite 30B/ZnO/Ag₂O nanocomposite (CV: 99.21%, MB: 98.43%) compared to Cloisite 30B/Ag₂O (CV: 85.38%, MB: 83.62%) and Ag₂O (CV: 68.21%, MB: 66.41%) has more catalytic activity. The catalytic activity of Cloisite 30B/ZnO/Ag₂O using the sono-photocatalytic process had the maximum efficiency (CV: 99.21%, MB: 98.43%) at pH 8, time of 50 min, amount of 40 mM H₂O₂, catalyst dose of 0.5 g/L, and the concentration of 'CV + MB' of 5 mg/L. The catalyst can be reused in the sono-photocatalytic process for up to six steps. According to the results, •OH and h⁺ were effective in the degradation of the desired dyes using the desired method. Data followed the pseudo-first-order kinetic model. The method used in this research is an efficient and promising method to remove dyes from wastewater.

Visible-light driven dual heterojunction formed between g-C3N4/BiOCl@MXene-Ti3C2 for the effective degradation of tetracycline

In the present study, we have successfully formulated a dual heterojunction of g-C₃N₄/BiOCl@MXene-Ti₃C₂ (GCBM) which was found to be highly active in the visible region. GCBM was found to be highly efficient for the degradation of an antibiotic, tetracycline (TC) as compared to the individual constituting units; g-C₃N₄ and BiOCl. Maximum of 97% TC degradation rate was obtained within 90 min of visible light irradiation for initial concentration of 10 mg/L of TC. Optical analysis exhibited that the synthesized heterojunction showed high absorption in the complete spectrum. The reactive species specified by the scavenger study showed the major involvement of ^•O₂^- and ^•OH radicals. The charge transfer mechanism showed that 2 schemes were majorly involvement in which Z-scheme was formed between g-C₃N₄ and BiOCl and Schottky junction was formed between g-C₃N₄ and Mxene-Ti₃C₂. The formation of Schottky junction helped in inhibiting the back transfer of photogenerated charges and thus, helped in reducing the recombination rate. The synthesized photocatalyst was found to be highly reusable and was studied for consecutive 5 cycles that generalized the high proficiency even after repetitive cycles.