Tandem internal electric fields in intralayer/interlayer carbon nitride homojunction with a directed flow of photo-excited electrons for photocatalysis
Jinqiang Zhang, Xiaojie Tan, Lei Shi, Haijun Chen, Yazi Liu, Shuaijun Wang, Shuaijun Wang, Xiaoguang Duan, Mingbo Wu, Hongqi Sun, Shaobin Wang, Shaobin Wang
Abstract
Photocatalytic hydrogen production is a green technology while significantly impeded by the sluggish and uncontrolled charge dynamics for less electron accumulation on catalyst surface. Herein, we proposed an effective strategy of epitaxial growth of a van der Waals (VDW) homojunction on an intralayer homojunction of carbon nitride for a controlled charge flow. Experimental and simulation collectively disclosed a tandem internal electric field (IEF) in the integrated hybrid, stringing a lateral IEF along the intralayer homojunction with a vertical IEF within the VDW homojunction. The planar IEF dominates laterally dispersive movement of charge carriers for their efficient separations and mobilities, meanwhile the vertical IEF induces an oriented accumulation of the dispersive hot electrons to the catalyst surface for intensified hydrogen reduction. The tandem IEF renders the hydrogen evolution rate at 3.5-fold higher than in-planar homojunction, and 6.3 times higher than g-C 3 N 4 benchmark. This work realizes charge-directing dynamics for robust photocatalysis. • An intralayer/van der Waals (VDW) interlayer carbon nitride hybrid was synthesized. • A planar and a vertical internal electric field (IEF) were generated within the hybrid. • The tandem IEF results in directed electron flow and intensified photocatalysis. • The H 2 evolution rate was much higher than in-planar homojunction and benchmark.