Rapid and facile laser-assistant preparation of Ru-ZIF-67-derived CoRu nanoalloy@N-doped graphene for electrocatalytic hydrogen evolution reaction at all pH values

Abstract High temperature pyrolysis needs complicated and harsh preparative condition, such as inert gas protection, long reaction time and high pyrolysis temperature. This work reported that a cobalt-ruthenium nanoalloy coated with nitrogen- doped graphene (CoRu@NG-x) was rapidly prepared from Ru-ZIF-67 as precursors by laser engraving in air environment and at room temperature for the first time. The addition of a small amount of ruthenium in cobalt can further improve the hydrogen catalytic performance. CoRu@NG-3 (Ru, 0.18wt%) is an efficient HER electrocatalyst in a wide pH range. Compared with the reported ruthenium alloys, the content of ruthenium in CoRu@NG-3 is the lowest. It's worth noting that the optimal CoRu@NG-3 shows overpotentials of 62, 52 and 88 mV at the current density of 10 mA cm−2 in 1.0 M KOH, 0.5 M H2SO4 and 1.0 M PBS solution for HER catalysis. CoRu@NG-3 also has a good stability under all pH conditions. This study may offer a novel strategy to rapidly prepare electrode materials at room temperature and in the air.