Boost alkaline hydrogen evolution reaction by intermetallic charge transfer in perovskite ruthenate encapsulated in ZIF-67 derived cobalt sulfide nanoparticles.

[Display omitted] • A novel core–shell-like heterostructure constructed by Co 3 S 4 -embedded in carbon-encapsulated BaRuO 3 (BaRuO 3 @CS- x) was fabricated. • The HER activity of BaRuO 3 @CS-0.1 is superior to that of Pt/C. • The intermetallic charge transfer between the Co of Co 3 S 4 and the Ru of BaRuO 3 is responsible for the enhanced HER activity. Constructing and manipulating heterostructure is an effective strategy to prepare electrocatalysts with excellent performance for water electrolysis. Herein, an efficient alkaline hydrogen evolution reaction (HER) electrocatalysts, Co 3 S 4 -embedded in carbon-encapsulated BaRuO 3 (BaRuO 3 @CS-0.1), was synthesized through the sacrificial template method of ZIF-67 encapsulated BaRuO 3 precursors. By inheriting the exceptional merits of different ingredients, this heterostructure catalyst BaRuO 3 @CS-0.1 enables intermetallic charge transfer between Ru and Co with boosted HER kinetics, and thus displaying higher catalytic activity towards HER, as evidenced by the intensively theoretical calculations and experimental measurements. BaRuO 3 @CS-0.1 exhibits excellent HER performance, with the lowered overpotentials of 26 mV to achieve 10 mA cm−2 in comparison to the pristine BaRuO 3 (51 mV), which is also superior to Pt/C catalyst at large current density. Moreover, this heterostructure also demonstrates comparable oxygen evolution reaction (OER) activities with the representative electrocatalysts, delivering current densities of 10 mA cm−2 at a potential of 1.546 V for overall water splitting. These findings provide a rational route to optimize the performance of bulk electrocatalysts and endow them with richer electrochemical activity through this composite strategy. [ABSTRACT FROM AUTHOR]