POM derived UOR and HER bifunctional NiS/MoS2 composite for overall water splitting

Abstract A binder free electrode is fabricated by “planting” Anderson type polyoxometalate derived NiS/MoS2 “follower” on functional carbon paper. This electrode shows excellent UOR activity. In 1 ​M KOH containing 0.4 ​M urea, it only needs 1.42 and 1.43 ​V voltage to achieve 50 and 100 ​mA ​cm−2 current. On the contrary, to reach 50 and 100 ​mA ​cm−2, OER require 1.68 and 1.75 ​V. Besides promising UOR activity, the HER property of this electrode is also attractive. In urea containing electrolyte, its η10 and η100 are only 128 and 283 ​mV. More importantly, it shows excellent stability in both UOR and HER. In electrolytic cell, with this electrode as cathode and anode simultaneously, only 1.42 and 1.49 ​V voltage is needed to obtain 10 and 50 ​mA ​cm−2 current in urea containing electrolyte. Without urea, the voltages increase to 1.69 and 1.75 ​V. The excellent UOR and HER properties suggest this binder free electrode is competent for low energy consumption H2 production.