Constructing stable charge redistribution through strong metal-support interaction for overall water splitting in acidic solution

Designing bifunctional electrocatalysts with high activity and durability for overall water splitting in acid electrolytes is still a huge challenge because their excellent activity is difficult to maintain. Herein, a method to stabilize the charge redistribution on catalysts by constructing Pt-RuO 2 @KB heterostructures with strong metal-support interactions is proposed first to achieve remarkable water splitting performance in acidic media. By performing X-ray photoelectron spectroscopy (XPS) before and after a 150 h long-time v - t test, it is found that the electron transfer from Pt to RuO 2 could form a stable charge redistribution. Benefiting from the Pt-RuO 2 heterostructures, the strong metal-support interaction (SMSI) between Pt-RuO 2 and KB as well as the stable charge redistribution between Pt and RuO 2 , Pt-RuO 2 @KB exhibits ultrahigh intrinsic activity (the turnover frequency (TOF) value is 34.5 s −1 @ 300 mV for the oxygen evolution reaction (OER) and 20.2 s −1 @ 100 mV for the hydrogen evolution reaction (HER), respectively) and outstanding overall water splitting performance (only needs 1.54 V at a current density of 10 mA cm −2 ). Notably, Pt-RuO 2 @KB with the stable charge redistribution exhibits striking stability for overall water splitting; during a 150 h continuous v - t test, the voltage is maintained well without noticeable degradation in 0.1 M HClO 4 . Density functional theory (DFT) calculations verify that the charge redistribution between Pt and RuO 2 can dramatically lower the water splitting barrier and raise the vacancy formation energy of atoms in the catalyst, which could effectively inhibit the dissolution of atoms in Pt-RuO 2 @KB in an acidic medium and achieve superior water electrolysis performance. A method through the SMSI and heterostructure of Pt-RuO 2 @KB to construct a stable charge redistribution is first proposed, showing superior overall water splitting performance, with excellent intrinsic activity, catalytic activity and stability in 0.1 M HClO 4 electrolyte.