Novel cobalt nanorods@ cobalt-platinum nanoparticles for electrocatalytic hydrogen evolution reactions and oxygen evolution reactions study

In this work, we prepared a novel material of cobalt nanorods@ cobalt-platinum nanoparticles using a facile, green method. We used a hydrothermal method to first synthesize a cobalt nanorod, which was used as a substrate material on which a ZIF-67 MOF structure was controllably loaded, and then, platinum was loaded into the MOF using a redox substitution reaction, resulting in the formation of a new type of nanocomposites, cobalt nanorods@ cobalt-platinum nanoparticles. The composites were successfully doped with a small amount of precious metal platinum into cobalt nanorods @ cobalt MOF by replacement method, which combines the unique structure of cobalt nanorods, cobalt MOF and high electrocatalytic performance of platinum, realizes the organic combination of precious metal-transition metal and effectively improves the electrocatalytic performance of the composites. The novel composites Co NRs@Co10–Pt1 NPs exhibit high catalytic activity and stability for the hydrogen and oxygen evolution reactions, Tafel slopes is 25 mV dec−1 in HER and 56 mV dec−1 in OER. This work provides a new idea for the preparation step of novel transition metal-precious metal composites and contributes to the effective improvement of the material's performance in electrocatalytic water decomposition reaction.