Highly Conjugated Graphitic Carbon Nitride Nanofoam for Photocatalytic Hydrogen Evolution
Chuanqi Cheng, Yi Feng, Zi‐Zheng Shi, Yunlong Zhou, Wenjing Kang, Zhe Li, Jing Mao, Gurong Shen, Cunku Dong, Hui Liu, Xi‐Wen Du
Abstract
As a metal-free photocatalyst, graphitic carbon nitride (g-CN) shows great potential for photocatalytic water splitting, although its performance is significantly limited by structural defects due to incomplete polymerization. In the present work, we successfully synthesize highly conjugated g-CN nanofoam through an iodide substitution technique. The product possesses a high polymerization degree, low defect density, and large specific surface area; as a result, it achieves a hydrogen evolution rate of 9.06 mmol h–1 g–1 under visible light irradiation, with an apparent quantum efficiency (AQE) of 18.9% at 420 nm. Experimental analysis and theoretical calculations demonstrate that the recombination of photogenerated carriers at C–NHx defects was effectively depressed in the nanofoam, giving rise to the high photocatalytic activity.