Preparation of Hierarchical Cube-on-plate Metal Phosphides as Bifunctional Electrocatalysts for Overall Water Splitting.

To rationally design efficient and cost-effective electrocatalysts, a simple but efficient strategy has been developed to directly anchor prussian blue analogue (PBA) nanocubes on cobalt hydroxide nanoplates (PBA@Co(OH)2 ) via the in-situ interfacial precipitation process. Subsequently, the thermal treatment in the presence of sodium hydrogen phosphite enabled the successful transition into metal phosphides with the hierarchical cube-on-plate structure. When used as electrocatalytsts, the obtained bimetal phosphides exhibited good bifunctional electrocatalytic activities for hydrogen and oxygen evolution reactions with good long-term stability. Thus, an enhanced performance for overall water splitting can be achieved, which could be ascribed to the hierarchical structure and favorable composition of as-prepared bimetal phosphide for rapid electron and mass transfer. The present study demonstrates a favorable approach to modulate the composition and structure of metal phosphide for enhancing the electrocatalytic ability toward water splitting.