Electrochemically synthesized tin selenide thin films as efficient electrocatalyst for overall water splitting

The objective of this study was to report electrocatalytic activity of tin selenide (SnSe) for oxygen evolution process (OER) and hydrogen evolution reaction (HER). Simple and inexpensive SnSe thin films were deposited onto a steel substrate using an electrodeposition method. Orthorhombic SnSe required a low overpotential value of 325, 317, 314 mV for OER and a low overpotential value of 273, 219, 194 mV for HER for SnSe-1, SnSe-2, and SnSe-3 electrodes, respectively, to reach a current density of 10 mA/cm2. The thickness of thin film increased over time 50, 60, and 70 min for each successive SnSe-1 to SnSe-3 samples. SEM image indicated crystalline in nature with compact grain-like morphology on the entire surface of the substrate. The SnSe-3 sample displayed low Tafel slopes of 90 and 68 mV/dec for OER and HER, respectively. EDX showed that atomic percentage ratio of Sn: Se was 54:46 for SnSe-3 thin film. Overall results suggest that electrochemically synthesized SnSe is a promising candidate as an efficient electrocatalyst for overall water splitting.