Thin In‐Plane In<sub>2</sub>O<sub>3</sub>/ZnIn<sub>2</sub>S<sub>4</sub> Heterostructure Formed by Topological‐Atom‐Extraction: Optimal Distance and Charge Transfer for Effective CO<sub>2</sub> Photoreduction
Lin Zhao, Bixia Yang, Guoxin Zhuang, Yonglin Wen, Tingshi Zhang, Mingxiong Lin, Zanyong Zhuang, Yan Yu
Abstract
Abstract Exploitation of atomic‐level principles to optimize the charge transfer on ultrathin 2D heterostructures is an emerging frontier in relieving the energy and environmental crisis. Herein, a facile “topological‐atom‐extraction” protocol is disclosed, i.e., selective extraction of Zn from ultrathin half‐unit‐cell ZnIn 2 S 4 (HZIS) can embed thin In 2 O 3 domain into 1.60 nm thick HZIS layer to create an atomically thin in‐plane In 2 O 3 /HZIS heterostructure. Thanks to the optimal distance and capability of charge separation, the in‐plane In 2 O 3 /HZIS heterostructure is among the best ZnIn 2 S 4 ‐based CO 2 reduction reaction (CRR) photocatalysts, and indeed demonstrates a significant increase (from 6.8‐ to 128‐fold) in CO production rate compared with those of out‐plane ZIS@In 2 O 3 and out‐plane In 2 O 3 ‐HZIS calcined heterostructures. Density Functional Theory simulation reveals that whereas the out‐plane heterostructure has a much smaller ∆q of 0.2–0.25 e, the in‐plane heterostructure with “zero distance contact” has an optimal ∆q of 1.05 e between In 2 O 3 and HZIS that induces remarkable charge redistribution on the in‐plane heterojunction interface and creates local electric field confined within the ultrathin layer. The charge redistribution efficiently directs the charge‐carrier separation in S‐scheme photocatalytic system and endows long‐lifetime carrier to CRR active HZIS. The findings demonstrate the strong versatility of engineering atomic‐level heterojunctions for efficient catalysts design.