Enhanced Hydrogen Evolution Reaction Performances of Ultrathin CuBi2O4 Nanoflakes

Abstract

Semiconductor catalysts play a potential role for efficient electrocatalytic hydrogen production. In this work, copper bismuth oxide (CuBi2O4) nanostructures were synthesized via the coprecipitation method using two different Cu precursors: one is Cu(NO3)(3)center dot 9H(2)O and the other is CuCl2. When using Cu(NO3)(3)center dot 9H(2)O, the sample showed an interconnected and aggregated irregular spherical CuBi2O4 nanoparticle structure. On the other hand, the CuCl2-derived CuBi2O4 sample exhibited an interconnected ultrathin nanoflake structure. The CuBi2O4 nanoflakes displayed a higher electrochemically active surface area (160 cm(2)) than the CuBi2O4 nanoparticle (116 cm(2)). Accordingly, the CuBi2O4 nanoflakes revealed an excellent hydrogen evolution reaction performance with a low Tafel slope (117 mV/dec) and a small overpotential (384 mV at 10 mA/cm(2) in 1 M KOH). These results specify that the CuBi2O4 nanoflakes are a suitable electrocatalyst material for high-performance water splitting.