Z-scheme 2D/2D g-C3N4/Sn3O4 heterojunction for enhanced visible-light photocatalytic H2 evolution and degradation of ciprofloxacin

Abstract

Photocatalytic water splitting for H2 production and antibiotics pollution removals under wide solar spectrum illumination have been broadly investigated. Graphitic carbon nitride (CN) based binary heterogeneous composite is an important component in artificial photosynthesis. In this work, a novel all-solid-state direct Z-scheme photocatalyst based on CN/Sn3O4 heterojunction is successfully synthesized using a simple calcination strategy. Sn3O4 nanosheets were well dispersed on the surface of CN to establish 2D-2D heterostructure. Benefiting from the wide visible light response of Sn3O4 and the facilitated charge transfer from Sn3O4 to CN for the band alignment, CN/Sn3O4 composite exhibits fascinating photocatalytic H2 evolution and ciprofloxacin degradation. In particular, CN/Sn3O4-3 with 3 wt% of Sn3O4 performs the optimum photocatalytic H2 production activity (98.07 μmol·h-1) and the degradation rate constant is about 3.4 times than CN under visible light irradiation. The enhanced photocatalytic performance mainly derived from the fabrication of direct Z-scheme heterojunction, which maximizes the photo redox capacity of composite. This work will provide new insight into the design of 2D photocatalysts with considerable catalytic activity for water splitting and pollutants degradation.