A/B-Site Management Strategy to Boost Electrocatalytic Overall Water Splitting on Perovskite Oxides in an Alkaline Medium .

In this paper, Pr 0.7 Sr 0.3 Co 1- x Ru x O 3 perovskite oxides were synthesized by the sol-gel method as bifunctional catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The overpotentials of PSCR0.05 against HER and OER at 10 mA cm -2 were 319 and 321 mV in alkaline medium, respectively. The Tafel slopes of HER and OER were 87.32 and 118.1 mV/dec, respectively. PSCR0.05 showed the largest electrochemical active area, the smallest charge transfer resistance, and excellent long-term durability. Meanwhile, the PSCR0.05 electrocatalyst was applied for overall water splitting and its cell voltage was maintained at 1.77 V at 10 mA cm -2 . The super-exchange interaction between adjacent RuO 6 -CoO 6 octahedra in perovskite made of PSCR0.05 contains sufficient active sites (such as Co 2+ /Co 3+ , Ru 3+ /Ru 4+ , and O 2 2- /O - ). The increase of surface oxygen vacancy and active site is the main reason for the improvement of difunctional catalyst performance. In this work, the electrocatalytic performance of perovskite-type oxides was further optimized by the method of A- and B-site cationic doping regulation, which provides a new idea for perovskite-type bifunctional electrocatalysts.