Efficient photocatalytic hydrogen evolution: a novel multi-modified carbon nitride based on physical adsorption

Abstract

In this work, carbon nitride was subjected to multiple innovative modifications. Firstly, a potassium-doped primary modification system was established, and then 1,2-benzisothiazolin-3-one (BIT) was physically adsorbed onto the surface of carbon nitride, which altered the surface charge distributions to generate an accelerating electric field. Under light illumination, photogenerated electrons can be transferred from the carbon nitride surface to the whole BIT molecule via the S atom under the accelerating electric field, and the photogenerated holes are trapped by various defects, which leads to a significant improvement of the charge separation efficiency. Its hydrogen evolution efficiency is 21.35 mmol g⁻¹ h⁻¹, which is 24 times higher than that of g-C₃N₄. The physisorption system in this paper offers a new direction for the multiple modification of carbon nitride to improve the hydrogen evolution reaction.