Green synthesis of Fe2O3 deposited g-C3N4: Addition of rGO promoted Z-scheme ternary heterojunction for efficient photocatalytic degradation and H2 evolution reaction

Abstract

Construction of heterojunction photocatalysts with robust charge separation, efficiency light utilization and better charge transportation are hotspot in photocatalytic energy and environmental remediation applications. Herein, we have prepared the Z-scheme ternary heterojunction (rGO/g-C3N4/Fe2O3) photocatalysts using green tea extract assisted hydrothermal method for visible-light active photocatalytic degradation and H2 production. The heterojunction formation provides the more active sites for photocatalytic redox reaction in comparison with pure photocatalysts, which was confirmed by BET analysis. Moreover, elemental trapping experiment, photocurrent analysis, and band alignment derived from valance band XPS, clearly revealed that, the prepared photocatalyst shows Z-scheme charge separation. Photocatalytic activity demonstrated that, the prepared Z-scheme heterojunction exhibits 97 and 94% of degradation efficiency against methylene blue (MB) and ciprofloxacin (CIP) model organic pollutants. Moreover, the ternary heterojunction photocatalyst exhibits almost 100% of recycling efficiency towards H2 production even at 5th cycle with 20,786 μmol/g. Hence, we hope that this green synthesis approach would provide the new way to prepare the heterojunction photocatalysts for energy and environmental remediation applications.