BaWO4/g-C3N4 heterostructure with excellent bifunctional photocatalytic performance

Abstract A novel bifunctional BaWO4/g-C3N4 photocatalyst with heterojunction was first synthesized by a hydrothermal-calcination method. The as-prepared catalysts were imposed in treatment of NOx in air and hydrogen produced from water. The chemical composition of BaWO4/g-C3N4 was optimized and composites with 7% BaWO4 (7%-Ba-CN) exhibited the best photocatalytic performance. In 30 min, the NOx removal ratio of the composite photocatalyst increased by 14% compared with the pure g-C3N4. According to in situ DRIFTS spectra analysis, the transformation pathways of photocatalytic purification of NO on pure g-C3N4 and 7%-Ba-CN were elucidated and compared, and a new adsorption band at 2164 cm−1 associated with NO+ intermediate was discovered on 7%-Ba-CN. In addition, the photocatalytic hydrogen production rate of 7%-Ba-CN was 2743.98 μmol/g/h, which was 4 times higher than that of pure g-C3N4. This research highlights that charge transfer rates can be controlled by constructing heterojunctions. The promotion of the charge separation, transmission and conversion could simultaneously enhance the oxidation and reduction capacity of the composite photocatalyst.