Investigation of 2D-layered photocatalytic semiconductors with enhanced heterojunction region for photocatalytic degradation

An effective approach to realize high-efficiency photocatalysts is the stable formation of heterojunction composite and increasing the junction area. We report that a facile fabrication method was proposed to form a stable heterojunction composite of SnS/g-CN, and a favorable coupling of SnS and g-CN at the interfaces was aimed at maximizing the heterojunction area. The degradation of methylene blue (MB) dye under exposure to low-power visible LED was sufficiently enhanced by the synthesized SnS/g-CN photocatalyst. From the experiments, the SnS nanosheet/g-CN microsheet heterostructure exhibited a high apparent pseudo-first order rate constant k of 0.0274 min, four and two times higher than the k value of SnS and g-CN, respectively. The cyclic experiments showed that the as-prepared heterojunctions exhibited good stability even without recovery treatment. X-ray photoelectron spectroscopy (XPS) analysis and MB adsorption curves explained the mechanism of the enhanced photocatalytic performance by increasing the 2D/2D heterojunction area. This study provides an efficient method for designing effective two-dimensional heterojunctions for photocatalytic applications.