Ru−RuO2 Nanoparticles Decorated on Various Substrates via Reduction‐Hydrolysis Strategy for Boosting Overall Water‐Splitting Performance

Abstract Engineering bifunctional nanocomposites with pronounced interfacial structure represents an effective design strategy for water‐splitting catalysts. Herein, a facile reduction‐hydrolysis method is described for the fabrication of Ru−RuO 2 hybrid nanocomposites on various substrates [Ni foam (NF), carbon nanotubes (CNT) and graphene oxide (GO)] as overall water‐splitting catalysts. Polydopamine (PDA) is the key element for simultaneously fabricating the Ru−RuO 2 hybrids as a moderate reductant by controlling the reduction rate. In the synthesis process, a gradual reduction of Ru 3+ to Ru 0 in the presence of PDA occurred during the hydrolytic process of Ru 3+ to form RuO 2 ⋅ n (H 2 O). After calcination, Ru−RuO 2 hybrids with tight interfacial contacts and high electrical conductivity exhibited excellent performance for both HER and OER. Especially, Ru−RuO 2 hybrids on the NF (Ru−RuO 2 /NC/NF) achieved outstanding catalytic activity toward HER and OER with overpotential of 24 mV and 223 mV at a current density 10 mA cm −2 in alkaline solution, respectively. This work provides a new method for facile synthesis and engineering of Ru−RuO 2 nanoparticles on various substrates for boosting the HER/OER performance.