Hierarchical NiSe@Ni nanocone arrays electrocatalyst for oxygen evolution reaction

Developing an oxygen evolution reaction (OER) electrocatalyst with low cost, abundant reserve and excellent performance is essential for extensive application of clean and renewable hydrogen energy. The present work proposed to fabricate hierarchical NiSe-based nanocone arrays on stainless steel (SS) for OER. Firstly, nickel nanosheet array was electrodeposited on SS (Ni/SS). Then, the Ni/SS was selenized via hydrothermal to form NiSe@Ni/SS. Finally, activation was performed by consecutive CV scans to convert NiSe into O-NiSe (O-NiSe@Ni/SS). The influence of selenization temperature and duration time on the morphology and OER performance were systematically investigated. Results showed that the optimized O-NiSe@Ni/SS performed high OER activity and good stability in 1.0 M KOH (pH = 14). To provide a current density of 10 mA cm(-2), an overpotential of 290 mV was needed and a small Tafel slope of 48 mV dec(-1) was observed. The good OER performance was attributed to the reduced charge transfer resistance and increased electrochemical active sites. (C) 2020 Elsevier Ltd. All rights reserved.