A novel photoelectrochemical detector based on 2D SnSSe porous nanoplates with atom-level heterojunctions

Abstract

Designing novel and highly efficient photodetectors is a significant work as well as full of challenges. Herein, 2D SnSSe (SSS) porous nanoplates (Sn: S: Se=1: 1: 0.5) with atom-level heterojunctions were obtained from optimized hydrothermal synthesis , and a novel SSS-based photoelectrochemical detector was constructed accordingly. The morphology, microstructure , chemical states and light absorption performance of the SSS sample were clearly revealed by various characterization methods. Further analysis showed that there was an internal electric field in the SSS sample, which resulted from no coincide centers of the positive and negative charge. Due to the internal electric field and porous structure, the SSS sample had lower internal resistance (0.3 KΩ), which was conducive to the transmission of internal carriers, and could enhance the photoelectrochemical (PEC) activity eventually. In addition, a possible schematic illustration of the SnSSe-based photodetector was accordingly proposed. This SnSSe-based photodetector exhibited a higher photocurrent density (262.8 μA/cm 2 ) that was 28.9 and 4.8 times of the SnS 2 and SnSe 2 and showed a higher photo-responsivity (0.24 mA/W) with a higher response speed. Moreover, the conduction band position of the SSS sample was higher than the O 2 /•O 2 − and H + /H 2 from band structure analysis, revealing it could also be used as a photocatalyst in photocatalytic degradation and photocatalytic hydrogen production. This pioneering work put forward a new scheme for the preparation of ternary SnSSe and revealed its potential application in the field of photodetection. 2D SnSSe (SSS) porous nanoplates (Sn: S: Se=1: 1: 0.5) with atom-level heterojunctions were obtained from optimized hydrothermal synthesis, and a novel SSS-based photoelectrochemical detector was constructed accordingly. In addition, a possible schematic illustration of the as-prepared SnSSe-based photodetector was accordingly proposed. Thanks to the internal electric field and porous structure, the SSS sample had lower internal resistance (0.3 KΩ), which was conducive to the transmission of internal carriers, and could enhance the photoelectrochemical (PEC) activity eventually. This SnSSe-based photodetector exhibited a higher photocurrent density (262.8 μA/cm 2 ) that was 28.88 and 4.79 times of the SnS 2 and SnSe 2 and showed a higher photo-responsivity (0.240 mA/W) with a higher response speed. Moreover, the conduction band position of the SSS sample was higher than the O 2 /•O 2 − and H + /H 2 from band structure analysis, revealing it could also be used as a photocatalyst in photocatalytic degradation and photocatalytic hydrogen production. This pioneering work put forward a new scheme for the preparation of ternary SnSSe and revealed its potential application in the field of photodetection. • novel atom-level heterojunction 2D SnSSe porous nanoplates were obtained. • The photoelectrochemical activity of the SnSSe-based photodetector is largely enhanced. • The photocurrent of the SnSSe-based photodetector has an enhancement of 28.88 times. • The photo-responsivity and response speed of the SnSSe-based photodetector has a large enhancement.