Activating Inert Carbon Atoms in Poly(Heptazine Imide) via Doping Engineering for High‐Efficiency Photocatalytic Water Oxidation
Zhiming Pan, Xingdian Zhu, Xirui Zhang, Mingyang Qie, Guigang Zhang, Yuanxing Fang
Abstract
Abstract Photocatalytic water oxidation half‐reaction is a critical bottleneck in achieving efficient overall water splitting using polymeric photocatalysts, primarily due to the lack of efficient water oxidation sites and sluggish reaction kinetics. To address these challenges, a doping engineering strategy is proposed to activate inert carbon atoms as efficient water oxidation sites in poly(heptazine imide) (PHI). Computational analysis revealed that Rb + dopants can induce in‐plane structural distortions in PHI, thereby modulating the electronic structure of carbon atoms. This modulation enhanced the adsorption of *OH intermediates on carbon atoms and significantly reduced the reaction barrier for water oxidation. Furthermore, charge carriers dynamics uncovered that the incorporation of the Rb + ions into the PHI framework can promote the photoexcited exciton dissociation and induce the holes to migrate to the water oxidation sites. As a result, the Rb‐doped PHI achieved an excellent apparent quantum efficiency value of up to 20.4% at 400 nm for water oxidation. This finding offers a new channel for researchers to develop highly efficient polymeric photocatalysts for photocatalytic water oxidation reactions.