Electrodeposition and Characterization of a Tin Sulfide-Electrochemically Reduced Graphene Oxide Heterojunction

This work shows the formation of a heterojunction between tin (II) sulfide (SnS) and electrochemically reduced graphene oxide (ERGO), carried out through two electrochemical steps. In the first step, graphene oxide (GO) was electrochemically reduced on a fluorine-doped tin oxide (FTO) electrode. In the second step, the ERGO/FTO substrate was used as an electrode for the electrodeposition of SnS. In this study, each electrodeposited material (ERGO, SnS and SnS/ERGO heterojunction) was analyzed and characterized using different techniques, which confirmed the SnS/ERGO heterojunction formation. By employing electrochemical impedance spectroscopy (EIS) and linear sweep photovoltammetry measurements, it was confirmed that SnS deposited in both, bare FTO and ERGO, is a p-type semiconductor. Furthermore, an improvement of the photocatalytic properties of the SnS/ERGO photocathode in comparison with the SnS film was observed. This effect is related to the ERGO interlayer between the SnS film and the FTO electrode, and the structural and morphology modification of the SnS film onto ERGO.