Promoting the generation of active sites through "Co-O-Ru" electron transport bridges for efficient water splitting

Exploring the intrinsic reasons for the dynamic reconstruction of catalysts during electrocatalytic reactions and their impact on activity enhancement still faces severe challenges. Herein, the bifunctional catalyst Ru/V-CoO/CP with doping strategy and heterostructure was synthesized for overall water splitting. The Ru/V-CoO exhibits excellent activity for HER and OER with low overpotentials of 49, 147 mV at a current density of 10 mA/cm2 in 1.0 mol/L KOH, respectively. The assembled electrolytic cell just needs voltages of 1.47 and 1.71 V to achieve 10 and 350 mA/cm2 current density under the same conditions and delivers an outstanding stability for over 100 hours, which is far superior to the commercial RuO2||Pt/C cell. Experimental and theoretical results indicate that the doping of V species and the formation of heterostructures lead to charge redistribution. More importantly, the leaching of V species induces electron transfer form Co to O and then Ru through the Co-O-Ru electron bridge, optimizes the adsorption strength of the key intermediate, thereby reducing the free energy barrier of the rate-determining step and improving catalytic activity. This work proposes an effective strategy of using cation dissolution to induce electron transfer through the electron bridge and thus regulate the electronic structure of catalysts, providing new ideas for the design and development of efficient and stable electrocatalysts. V doped Ru/V-CoO/CP with heterostructures was synthesized for overall water splitting. The leaching of V species promotes electron transfers from Co to Ru through the “Co-O-Ru” electron bridge, which facilitates the reconstruction of the catalyst to form the truly active species. As a result, Ru/V-CoO/CP exhibits excellent electrocatalytic water splitting performance. [Display omitted]