Electron‐Deficient Engineering in Large‐Conjugate‐Heptazine Framework to Effectively Shuttle Hot Electrons for Efficient Photocatalytic H<sub>2</sub>O<sub>2</sub> Production
Ronglan Pan, Wei Lv, Xin Ge, Xiong Huang, Qichuan Hu, Kejian Song, Qiong Liu, Haibo Xie, Bo Wu, Jili Yuan
Abstract
Abstract Photocatalytic oxygen reduction to H 2 O 2 based on g‐C 3 N 4 has presented promising potential for sustainable solar‐fuel production. Yet tuning the timescale of hot electron's lifetime to effectively participate in the surface reactions remains challenging. Here, an electron‐deficient engineering strategy is developed by incorporating an electron‐deficient structure (EDS) with different conjugate regions into large conjugate‐heptazine framework (LCHF) of g‐C 3 N 4 to steer hot electrons of the different timescales to effectively activate O 2 for efficient photocatalytic H 2 O 2 production. Femtosecond transientabsorption spectroscopy reveals that introducing EDS into LCHF can steer hot electron rapid transfer to the trapping sites of EDS and notably eliminate the deeply trapped electrons as well as enhance the shallow capture. It is demonstrated that pyromellitic dianhydride not only can tune the lifetime scale of hot electrons but also provide nonpolarized active sites to effectively activate O 2 forming H 2 O 2 with lower energy barrier via direct or stepwise 2e − pathways. This photocatalyst achieves an H 2 O 2 yield rate of 25.40 mmol g −1 h −1 , enabling an apparentquantumyield of 45.7% at 400 nm and a solar‐to‐chemical efficiency of 2.63%, outperforming the other reported photocatalysts. This work will shed light on the design of organic photocatalysts to tune hot electrons to effectively engage in the surface reaction.