Recent advances in Ni (oxy) hydroxides and Ni sulfides catalysts for oxygen evolution reactions

•Ni-based oxygen evolution reaction (OER) catalysts are highly active and earth abundant, and becoming the most promising catalyst for industry.•The multiple phases of Ni (oxy)hydroxides and Ni sulfides under reaction condition are summarized.•The high performance of Fe doped Ni (oxy)hydroxides is discussed in detail.•The active phases and surface reconstruction of Ni (oxy) hydroxides and sulfides under working conditions have been reviewed.•The discrimination between theory and experiments on the Ni sulfides due to surface reconstruction are analyzed.•The Electrolyte effect on OER including anions and cations are summarized.