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

Graphical Electrocatalytic water-splitting : A facile reduction-hydrolysis strategy was developed to fabricate a Ru−RuO 2 hybrid on various substrates (Ni foam, graphene and CNT) as bifunctional electrocatalysts for water-splitting. 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.