In situ DRIFT investigation on the photocatalytic NO oxidation mechanism with thermally exfoliated porous g-C3N4 nanosheets

Abstract

Bulk g-C₃N₄ suffers from a low surface area and high charge recombination rate. To advance the photocatalytic efficiency of g-C₃N₄, porous g-C₃N₄ nanosheets were prepared using a simple thermal exfoliation method. The effects of thermal exfoliation time on the microstructure and photocatalytic performance of g-C₃N₄ was investigated. Porous g-C₃N₄ nanosheets treated for 4 h (C₃N₄-4h) exhibited a highly enhanced NO removal ratio of 51.2%, which is 3.2 times higher than that of bulk g-C₃N₄. The enhanced activity of C₃N₄-4h can be ascribed to an increased surface area and promoted charge separation. An in situ DRIFT investigation was applied to monitor the time-dependent NO adsorption–photocatalysis process. Based on the observed reaction intermediates, a molecular-level mechanism for photocatalytic NO oxidation with porous g-C₃N₄ nanosheets was proposed.