Enhanced hydrogen evolution and tetracycline degradation by a Z-scheme g-C3N4 nanosheets loaded CeO2 photocatalyst under visible light irradiation

In the quest to enhance photocatalytic performance, structural regulation and interface engineering stand out as effective strategies for amplifying active sites and fostering the separation of photogenerated electron-hole pairs. In this study, a pioneering approach was employed, utilizing a straightforward two-step calcination method to prepare a novel photocatalyst: porous graphite carbon nitride (g-C3N4, CN) nanosheets (NS) loaded with mesoporous cerium oxide (CeO2/CNNS). The distinctive architecture of CeO2/CNNS not only elevates the specific surface area and catalytic active sites but also facilitates efficient mass transfer. Experimental results and density functional theory (DFT) calculations corroborate the existence of an internal electric field (IEF) within the Z-scheme heterojunction formed by uniformly dispersed CeO2 and CNNS. This IEF proves pivotal in promoting charge separation and migration, thereby maintaining robust redox capabilities. Under visible light irradiation, CeO2/CNNS demonstrates an impressive 4.2-fold increase in the hydrogen production rate compared to bulk g-C3N4 (BCN), coupled with a 48.5% boost in the photocatalytic degradation rate constant (k) of tetracycline (TC). This study not only unveils the innovative design of CeO2/CNNS but also paves the way for a fresh perspective on the design and preparation of multifunctional photocatalysts. [Display omitted] •Novel Z-scheme CeO2/CNNS heterojunction was prepared by secondary calcination.•High redox capacity and charge separation efficiency were achieved by the Z-scheme.•Internal electric field in the interface of CeO2/CNNS was proved by DFT calculation.