An overview of strategies for enhancement in photocatalytic oxidative ability of MoS2for water purification

Abstract

MoS2 is a noble metal-free, earth-abundant, light-harvesting photocatalyst with simple synthesis techniques and diverse morphological modulations which provides more surface reactive sites for pollutant adherence. Notably, its tunable band edge potential between 1.2-1.9 eV depicts its visible light-responsive ability. The layered 2D structure is responsible for the high mobility of photoinduced charge carriers which makes the photodegradation process rapid and highly stable. However, n-type pristine MoS2 semiconductor photoactivity is hindered by insufficiency to generate ·OH radical which ultimately reduces the photooxidative ability of MoS2 photocatalyst. As a single semiconductor material, the large-scale application of MoS2 is still limited. In this review, we provide a brief structural and synthesis overview with updated research progress on MoS2 based heterojunctions i.e. traditional type II, all-solid-state and direct Z-scheme photocatalytic systems. They are beneficial for considerable charge separation, wide optical absorption, and improved redox ability, whereas Z-scheme heterostructures particularly provide amended oxidative ability for maximum pollutant eradication. Summary remarks the need for mechanism investigation inferring photoinduced charge carrier's separation and possible approaches to improve the photooxidative potential of MoS2 with maximum recovery rate. Finally, a brief, conclusive remark regarding current studies and unresolved challenges of MoS2 photocatalyst are put forth for future perspectives.