Constructing hollow core-shell Z-scheme heterojunction CdS@CoTiO3 nanorods for enhancing the photocatalytic degradation of 2,4-DCP and TC.

Abstract

Constructing Z-scheme heterojunctions incorporating an exquisite hollow structure is an effective performance regulation strategy for the realization of high quantum efficiency and a strong redox ability over photocatalysts. Herein, we report the delicate design and preparation of a core-shell hollow CdS@CoTiO3 Z-scheme heterojunction with a CdS nanoparticle (NP)-constructed outer shell supported on a CoTiO3 nanorod (NR) inner shell. The in situ growth synthetic method led to a tightly connected interface for the heterojunction between CdS and CoTiO3, which shortened the transport distance of photoinduced charges from the interface to the surface. The promoted charge carrier separation efficiency and the retained strong redox capacity caused by the Z-scheme photoinduced charge-transfer mechanism were mainly responsible for the boosted photocatalytic performance. Additionally, the well-designed core-shell structure afforded a larger interfacial area by the multiple direction contact between CdS and CoTiO3, ensuring sufficient channels for efficient charge transfer, and thus further boosting the photocatalytic activity. As an efficient photocatalyst, the optimized CdS@CoTiO3 nanohybrids displayed excellent 2,4-dichlorophenol (2,4-DCP) and tetracycline (TC) degradation efficiencies of 91.3% and 91.8%, respectively. This study presents a Z-scheme heterojunction based on ecofriendly CoTiO3, which could be valuable for the development of metal perovskite photocatalysts for application in environmental remediation, and also demonstrated the tremendous potential of integrating a Z-scheme heterojunction with the morphology design of photocatalyts.