Molybdenum disulfide loading on a Z-scheme graphitic carbon nitride and lanthanum nickelate heterojunction for enhanced photocatalysis: Interfacial charge transfer and mechanistic insights

Abstract

Interfacial design and the co-catalyst effect are considered to be effective to achieve separation and transport of photogenerated carriers in composite photocatalysts. In this study, a Z-scheme heterojunction was successfully combined with a co-catalyst to achieve a highly efficient LaNiO3/g-C3N4/MoS2 photocatalyst. MoS2 flakes were loaded on a hybrid material surface, which was formed by LaNiO3 nanocubes embedded on layered g-C3N4, and a good heterostructure with multiple attachment sites was obtained. Experimental studies confirmed that the Z-scheme heterojunction completely preserves the strong redox ability of the photogenerated electrons and holes. As a cocatalyst, MoS2 further promoted interfacial charge separation and transport. The synergistic effect of the Z-scheme heterojunction and co-catalyst effectively realized the transfer of photogenerated carriers from “slow transfer” to “high transfer” and promoted water decomposition and pollutant degradation. Results revealed that under simulated sunlight irradiation, LaNiO3/g-C3N4/MoS2 composites exhibit superior hydrogen evolution of 45.1 μmol h−1, which is 19.1 times that of g-C3N4 and 4.9 times that of LaNiO3/g-C3N4, respectively. Moreover, the LaNiO3/g-C3N4/MoS2 Z-scheme photocatalyst exhibited excellent photocatalytic performance for antibiotic degradation and heavy-metal ion reduction under visible light. This study might provide some insights into the development of photocatalysts for solar energy conversion and environmental remediation.