Improved hydrogen evolution with SnS2 quantum dot-incorporated black Si photocathode

Enhanced photocatalytic performance of SnS2 under visible light irradiation: strategies and future perspectives

Tin(II) sulfide (SnS2) has emerged as a promising candidate for visible light photocatalytic materials. As a member of the transition metal dichalcogenides (TMDs) family, SnS2 features a band gap of approximately 2.20 eV and a layered structure, rendering it suitable for visible light activation with a high specific surface area. However, the application of SnS2 as a visible light photocatalyst still requires improvement, particularly in addressing the high recombination of electrons and holes, as well as the poor selectivity inherent in its perfect crystal structure. Therefore, ongoing research focuses on strategies to enhance the photocatalytic performance of SnS2. In this comprehensive review, we analyze recent advances and promising strategies for improving the photocatalytic performance of SnS2. Various successful approaches have been reported, including controlling the reactive facets of SnS2, inducing defects in the crystal structure, manipulating morphologies, depositing noble metals, and forming heterostructures. We provide a detailed understanding of these phenomena and the preparation techniques involved, as well as future considerations for exploring new science in SnS2 photocatalysis and optimizing performance.

Geometry-asymmetric photodetectors from metal-semiconductor-metal van der Waals heterostructures

The functional diversities of two-dimensional (2D) material devices with simple architectures are ultimately limited by immature doping techniques. An alternative strategy is to use geometry-asymmetric metal-semiconductor-metal (GA-MSM) structures, which enable the basic functions of semiconductor junctions such as rectification and photovoltaics. Here, the mixed-dimensional van der Waals heterostructures (MDvdWHs) based on the separation and self-assembly of p-type SnS layered nanosheets (NSs) and n-type SnS₂ nanoparticles (NPs) are obtained using an aqueous phase exfoliation (APE) method. Due to the surface charge transfer doping, the carrier transport mechanism of devices based on MDvdWHs turns from thermionic field emission (TFE) to thermionic emission (TE), with the rectification factor (I_forward/I_reverse) changing from 0.7 to 3. To further illustrate the experimental results, the generic current transport models of GA-MSM devices have been established based on the TE and TFE mechanisms in which the TE and TFE mechanisms lead to opposite rectification phenomena in good agreement with the experimental results. The GA-MSM devices show a photovoltaic effect with a high responsivity of 35 A W^-1 and detectivity of 3.4 × 10¹¹ cm Hz^1/2 W^-1. This study not only provides a novel strategy to design photovoltaic devices with MDvdWHs, but more importantly, we have established fundamental models for the rectification behavior of GA-MSM devices.