Hierarchical 2D/2D C-ZnIn₂S₄/O-PCN S-Scheme Heterojunction for Enhanced Photocatalytic Hydrogen Production

School of Mechanical Engineering, Tongji University, Shanghai 201804, China

^a 1810232@tongji.edu.cn
^b 2132729@tongji.edu.cn
^c 2132728@tongji.edu.cn
^d 2111412@tongji.edu.cn
^e* ljwu@tongji.edu.cn

Abstract

The heat agglomeration, inadequate optical absorption, significant electron-hole recombination are the main reasons resulting to the low photocatalytic activity of carbon nitride. Herein, based on O-defective functionalized carbon nitride, the C atoms are designed to insert into ZIS lattice to broaden light adsorption intensity and range to near-infrared light (NIR), then are adopted to construct a 2D/2D heterojunction of hierarchical C-ZnIn₂S₄/O-PCN nanoflower to enhance the photocatalytic hydrogen evolution of carbon nitride from water splitting. The successful incorporation of C atoms can be revealed by the elemental analysis, enhanced N2 adsorption, and deformation of crystal lattice in C-ZIS. A distinct curve edge of amorphous O-PCN and crystalline C-ZIS, confirm the formation of C-ZIS/O-PCN heterostructures. The optimal matchability is achieved as the mass ratio of C-ZIS to O-PCN is 1:1, which corresponds to the highest photocatalytic hydrogen evolution rate of 1274.8 μmol/g/h, 16.7 times higher than O-PCN. This enhancement is responsible for the largest 2D/2D surface contact, broadened optical adsorption intensity and range, rapid charge transfer at the interface, and the formation of S-Scheme route in the 50%C-ZIS/O-PCN heterojunction.