Construction of 3D/2D indium vanadate/graphite carbon nitride with nitrogen defects Z-scheme heterojunction for improving photocatalytic carbon dioxide reduction

Abstract

Indium vanadate (InVO4) possesses excellent potential in photocatalytic carbon dioxide (CO2) reduction, but further modifications of reducing charge recombination and increasing active sites are still needed. Herein, InVO4/g-C3N4 (InVO-CN) heterojunction composite photocatalysts were prepared via in situ formation of InVO4 nanoparticles on the lamellar structure of graphite carbon nitride (g-C3N4) containing nitrogen (N) defects. Among these composites, 30% InVO-CN showed the best photoreduction performance for CO2 at normal temperature and pressure without sacrificial agent (carbon monoxide, CO: 20.14 μmol g–1 h–1; methane, CH4: 3.46 μmol g–1 h–1), which were 1.8 and 2.8 times higher than these of pure g-C3N4 and InVO4. The excellent performance could be attributed to the enhancement of CO2 adsorption, and most importantly, the enhanced charge carrier separation and reduction capacity induced by the formation of Z-scheme heterojunction between InVO4 and g-C3N4. In this work, intimate heterojunction interfaces between materials were formed by introducing g-C3N4 with defects in InVO4, which provides a promising modification scheme.