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

Indium vanadate (InVO 4 ) possesses excellent potential in photocatalytic carbon dioxide (CO 2 ) reduction, but further modifications of reducing charge recombination and increasing active sites are still needed. Herein, InVO 4 /g-C 3 N 4 (InVO-CN) heterojunction composite photocatalysts were prepared via in situ formation of InVO 4 nanoparticles on the lamellar structure of graphite carbon nitride (g-C 3 N 4 ) containing nitrogen (N) defects. Among these composites, 30% InVO-CN showed the best photoreduction performance for CO 2 at normal temperature and pressure without sacrificial agent (carbon monoxide, CO: 20.14 μmol g –1 h –1 ; methane, CH 4 : 3.46 μmol g –1 h –1 ), which were 1.8 and 2.8 times higher than these of pure g-C 3 N 4 and InVO 4 . The excellent performance could be attributed to the enhancement of CO 2 adsorption, and most importantly, the enhanced charge carrier separation and reduction capacity induced by the formation of Z-scheme heterojunction between InVO 4 and g-C 3 N 4 . In this work, intimate heterojunction interfaces between materials were formed by introducing g-C 3 N 4 with defects in InVO 4 , which provides a promising modification scheme.