Abstract Electrocatalytic water splitting is a promising way for renewable energy conversion and storage, but efficient and low cost catalysts are essential mainly due to the sluggish oxygen evolution reaction (OER). Here, hierarchical Cu/Co selenide nanotubes assembled of nanosheets were successfully prepared. Benefiting from the rich active sites, highly exposed surface and enhanced charge transport, excellent electrocatalytic performance with a considerably low overpotential (238 mV at 10 mA cm −2 ), fast reaction kinetics (Tafel slop: 62 mV dce −1 ) and outstanding durability was achieved. Based on the ex‐situ characterizations, in‐situ formed (oxy)hydroxides were confirmed, which are presumably the intrinsic electrocatalytic sites for OER.