posted on 2022-01-19, 10:03authored byChuan-Qi Cheng, Yi Feng, Zi-Zheng Shi, Yun-Long Zhou, Wen-Jing Kang, Zhe Li, Jing Mao, Gu-Rong Shen, Cun-Ku Dong, Hui Liu, Xi-Wen Du
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.