CdS-sensitized 3D ordered macroporous g-C3N4 for enhanced visible-light photocatalytic hydrogen generation

Abstract

• A cost-effective strategy for constructing 3DOM g-C 3 N 4 /CdS was fabricated. • This heterostructure exhibits an enhanced photocatalytic H 2 evolution rate. • The 3DOM structure improves the light conversion and mass transfer efficiency. Carbon nitride (g-C 3 N 4 ) is an attractive photocatalyst but commonly suffers from high photogenerated electron-hole recombination rate, low specific surface area, and narrow visible-light response range. Herein, 3D ordered macroporous (3DOM) g-C 3 N 4 /CdS was constructed by a feasible and inexpensive synthesis strategy of using template and light-assisted methods to solve the above problems. The formed heterostructure with suitable morphology, band structure, and extended light absorption range is beneficial to promoting photocatalytic H 2 generation. 3DOM g-C 3 N 4 /CdS exhibits a high H 2 produce rate of 718.6 μmol h −1 g −1 , which is 73.3 times higher than that of g-C 3 N 4 and 25.4 times higher than that of 3DOM g-C 3 N 4 . The 3DOM structure can effectively increase the path length of light of g-C 3 N 4 , improve the light energy conversion efficiency, and shorten the carrier transport distance. CdS enhances visible-light response and produces many surface sites. Constructing a stable and tight interface between 3DOM g-C 3 N 4 and CdS can promote the migration of photogenerated electrons and holes and consequently the visible-light catalytic activity. This study offers an effective designing strategy for heterostructure photocatalysts to achieve high activity and stable solar H 2 production.