Synergic Delocalized‐Conjugate and Electron‐Deficient Effect and Mesoporous Channel Promote Photocatalytic Coupling H<sub>2</sub> Evolution with Benzyl‐Alcohol Oxidation
Ronglan Pan, Xin Ge, Qiong Liu, Hao Yin, Yuanlong Guo, Jiachao Shen, Danyu Zhang, Peng Chen, Jili Yuan, Haibo Xie, Chengbin Liu
Abstract
Abstract Photocatalytic merging H 2 evolution with benzyl‐alcohol (BA) oxidation offers a promising approach to producing H 2 and value‐added chemicals due to water photocatalysis with a sluggish kinetic process and gas‐mixed H 2 /O 2 gas security concern. Herein, incorporating electron‐deficient pyromellitic dianhydride into large π‐conjugate polymeric carbon nitride builds an effective in‐electric field (IEF). The resultant photocatalyst shows the dependence on the ratio of H 2 O and BA for H 2 and benzaldehyde production, particularly the highest yield rate of H 2 (13.87) and benzaldehyde (7.71 mmol h −1 g −1 ), 69.2% at 400 nm of internal quantum efficiency for H 2 ‐evolution, and 2.15% of solar‐to‐hydrogen efficiency under simulated AM 1.5G irradiation. Mechanism analysis suggests that the strong driving force of effective IEF originates from the cooperating large delocalized π‐conjugate and electron‐deficient effect, which overwhelms the intrinsic binding energy of charge carrier to enhance its separation and migration efficiency dramatically. Moreover, extended light response and mesoporous channel in photocatalyst improve the absorption edge and tail, the n→π* transition, and mass transport of BA. In situ characterizations revealed that the enhanced H 2 production is due to the releasing protons from BA oxidation via carbon‐centered radical‐mediated. These findings provide a novel strategy and deep understanding of photocatalytic coupling H 2 with added‐value chemical production.