Two-dimensional mesoporous g-C3N4 nanosheet-supported MgIn2S4 nanoplates as visible-light-active heterostructures for enhanced photocatalytic activity

Abstract

A series of novel visible-light-driven MgIn2S4/g-C3N4 (MISCN) heterostructures were fabricated in situ by a simple one-pot hydrothermal method. The synthesis of the MgIn2S4 (MIS) nanoplates and the construction of intimate interfacial contacts by loading MIS nanoplates onto mesoporous g-C3N4 (CN) nanosheets were achieved simultaneously in a hydrothermal environment. Systematic characterization, including powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–vis diffuse reflection spectroscopy (UV–vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), and photoelectrochemical measurements were employed to analyze the phase structure, chemical composition, absorption properties, microstructure, and photocatalytic mechanism. The as-prepared MISCN photocatalysts exhibit improved photocatalytic activity for 4-nitroaniline (4-NA) reduction and methyl orange (MO) degradation as compared with pure MIS nanoplates and pristine CN nanosheets under visible light irradiation. The enhancement of photocatalytic performance can be attributed to faster charge separation and transport benefitting from the construction of tight heterogeneous interfaces and band offset structure between MIS nanoplates and mesoporous CN nanosheets. This investigation may be extended to explore and fabricate the novel and highly efficient visible-light-driven g-C3N4-based heterostructures for organic transformations and pollutant removal.