Graphitic Carbon and Bimetallic Bismuth Oxide composites for Adsorption and Photocatalytic Removal of Toxic Pollutants

Abstract

Chapter-1 The chapter includes the structural and chemical composition of bimetallic bismuth oxide compounds, as well as their adsorptive and photocatalytic properties. The behaviour and changes of BBOs have been addressed in relation to adsorption and photocatalysis. This chapter also covers the literature evaluation, research gaps, objectives, experimental procedures, and characterisation methodologies. Chapter-2 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 (5wt.% g-CNatBiVO4 and 10wt.% g-CNatBiVO4) 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 10wt.% g-C3N4atBiVO4 hybrid possesses the best catalytic activity with 86% degradation efficiency after 60 minutes 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. Chapter-3 Because of unrestricted disposal, the concentration of reactive dyes in wastewater is gradually increasing. Owing to their eco-toxicity their removal becomes so crucial. In this regard, Bi (0)-doped g-C3N4/Bi2WO6 (g-C3N4/BiatBi2WO6) nanocomposites were prepared by wet impregnation followed by calc