Modulated BiOCl nanoplates with porous g-C3N4 nanosheets for photocatalytic degradation of color/colorless pollutants in natural sunlight. (July 2021) - Kundu, Aayushi
Abstract: Photocatalytic degradation of noxious pollutants is an efficacious approach to combat water pollution. The heterojunction photocatalysts having low band-gap and recombination-rate have immense significance in this respect. Herein, a series of composites (various weight ratios of g-C3 N4 @BiOCl) are constructed by conglomerating g-C3 N4 nanosheets with BiOCl nanoplates by a wet chemical process. XRD, XPS, EDX, and TGA analysis verified the successful formation, uniform distribution, and thermal stability of the catalysts. FESEM and HRTEM images exhibited that BiOCl platelets are well-covered with g-C3 N4 nanosheets. The UV-DRS and PL spectroscopy confirmed that the hybrid had a low bandgap and a low recombination rate facilitating charge separation. BET assay revealed that 3:1 g-C3 N4 @BiOCl had the highest surface area (107 m 2 /g) with mesopores. To assess the catalyst's photocatalytic performance, MB and IC were degraded in natural sunlight. Kinetic studies showed that the 3:1 g-C3 N4 @BiOCl hybrid manifested the best performance (degrading 94.8% of MB and 73.4% of IC) and rate constant (0.0301 min −1 and 0.0085 min −1 for MB and IC, respectively). An effect of pH and catalyst concentration on the photodegradation was also investigated. Trapping experiments revealed that O2 - was the major reactive species in the photodegradation mechanism. The successful IC degradation confirmed the occurrence of indirect photocatalysis. The catalyst was reused for MB degradation showing 75% efficiency even after 5 sequential cycles. Considering the simplistic preparation and excellent properties, g-C3 N4 @BiOCl can be used as a promising and competitive solar-light-driven photocatalyst for environmental remediation. Graphical abstract: Image 1 Highlights: Different weight ratios of g-C3 N4 @BiOCl hybrid were synthesized. 3:1 g-C3 N4 @BiOCl is the best catalyst among all the prepared materials. 94.8% of dye was degraded by the best hybrid with a rate constant of 0.0301 min −1 . 3:1 g-C3 N4 @BiOCl shows the efficiency of 73.4% for pesticide degradation.