g-C3N4/CoNiFe-LDH Z-scheme heterojunction for efficient CO2 photoreduction and MB dye photodegradation

Abstract

The development of efficient and stable photocatalysts to solve environmental issues is essential and remains a big challenge. In this work, flower-like CoNiFe-LDH is deposited in situ on g-C₃N₄ nanosheets, successfully constructing a Z-scheme heterojunction CoNiFe-LDH/g-C₃N₄ photocatalyst for the photoreduction of CO₂ and photodegradation of MB dye. The synthesized nanohybrid shows superior photocatalytic CO₂ performance (42.04 μmol g⁻¹ h⁻¹) and fast photodegradation MB performance (0.1057 min⁻¹). The improved photocatalytic performance was attributed to the formation of the Z-scheme heterojunction with matched energy bands, and the intimate heterojunction contact interface, which significantly enhanced the interfacial charge transfer rate and improved the separation efficiency of electron–hole pairs. Moreover, the photocatalytic mechanism was proposed based on PL, photocurrent responses, EIS, and EPR experiments. This work can shed light on further application for environmental problems of Z-scheme heterojunction photocatalysts.