High-efficient photocatalytic degradation of multiple pollutants by CdPS3 nanosheets

Photocatalytic degradation technique is an effective route for degrading the polluting sources by using photocatalysts. In recent years, van der Waals material based photocatalysts has been drawing more and more attention due to their excellent photodegradation performance. In this research, we have developed a type of highly efficient layered photocatalyst, CdPS3 nano flakes prepared by the liquid-phase exfoliation method. We compared different photodegradation rates of rhodamine B (RhB) by using photocatalysts of CdPS3 ground bulk powder and CdPS3 nanosheets exfoliated by three different dispersants, i.e., N-methyl pyrrolidone (NMP), deionized (DI) water and sodium cholate (SC). For a complete degradation of RhB (80 mL, 100 mg/L), the SC-exfoliated CdPS3 nanosheets exhibited the highest degradation efficiency within 15 min. These SC-exfoliated nanosheets also demonstrated good potential for degrading methylene blue (MB), potassium dichromate (PD), tetracycline (TC) and methyl orange (MO). The strong dark adsorption and dye-sensitized photocatalytic properties of CdPS3 nanosheets could both contribute to high degradation efficiencies of RhB and MB, synergistically. Capture experiments revealed that superoxide radicals dominated the degradations of these pollutants. Additionally, for PD and MO, hydroxyl radicals and holes were also important active species in the photodegradation redox reactions.