Simplistic preparation of Sn-doped MgIn₂S₄ for photocatalytic organic dye degradation under visible light irradiation

The increasing amount of dye wastewater presented significant environmental and public health concerns, underscoring the urgent need to develop an eco-friendly, cost-effective, and sustainable approach to wastewater treatment. Photocatalytic technology is an ideal candidate for wastewater treatment due to its low pollution, high efficiency, and easy operation. In this work, a series of Sn-doped MgIn₂S₄ photocatalysts were successfully prepared via the hydrothermal method. The 60%Sn–MgIn₂S₄ showed the best photocatalytic activity, with a degradation rate of 62.5% for methyl orange (MO) over a 60-min driven by visible light. 60%Sn–MgIn₂S₄ exhibited ideal stability, retaining 85% of its original degradation rate after four cycles of testing. Electrochemical impedance spectroscopy suggested that the 60%Sn–MgIn₂S₄ possessed the ideal photogenerated charge migration rates. In addition, the photocatalytic active species-capture experiments showed that ·O₂^– and ·OH were the main active species for the photocatalytic degradation of MO over 60%Sn–MgIn₂S₄. This research provided a significant foundation for the development of MgIn₂S₄-based photocatalytic materials.