Efficient OER nanocomposite electrocatalysts based on Ni and/or Co supported on MoSe2 nanoribbons and MoS2 nanosheets

•The NiCoMoSe, NiCoMo, CoMo, and CoMoSeS nanocomposites presented high OER catalytic responses.•The N atoms bonded to Ni and/or Co (and Mo) on the nanocomposites surfaces improved the OER responses.•The use of MoS2 nanosheets and MoSe2 nanoribbons as support for the nanocomposites decreased the charge transfer resistance.•The Fe impurities present in the 1 M KOH solution were not responsible for the high OER electrocatalytic responses.