Interfacial boron modification on mesoporous octahedral rhodium shell and its enhanced electrocatalysis for water splitting and oxygen reduction

Abstract

The research of active and efficient electrocatalysts is of great importance for the practical application of some energy conversion devices. Improving the catalytic activity and utilization efficiency of noble metal is of great importance for the practical application. Here, we report a one-pot synthesis of porous rhodium octahedra through a corner-induced-selective-deposition (CISD) process. After simple interfacial boron modification, the performances towards oxygen evolution reaction (OER), hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) in alkaline media were greatly enhanced. Especially, a small overpotential of 31 mV at 10 mA/cm2 was achieved for HER, and a high half-wave potential of 914 mV was obtained for ORR, much better than the commercial Pt/C catalysts (55 mV, 891 mV). Density functional theory (DFT) calculation reveals that the boron incorporation optimizes the adsorption properties of catalyst surface and in turn, lowers the overpotentials for the three reactions. This work may be extended to design other nanoscale functional materials with delicate nanostructures and optimized compositions.