Rational phase transformation and morphology design to optimize oxygen evolution property of cobalt tungstate.

ABSTRACT

In this work, a facile and feasible soft template method with the aid of buffer solution is successfully applied to synthesize high-order mesoporous cobalt tungstate for the first time. Attributing to the regulation of reaction solution's pH value and the existence of template, the phenomenon of phase transformation occurs, and high-order mesoporous structure is formed. Because of the variation of phase and morphology, only 448 mV can deliver a current density of 10 mA cm-2 with a small Tafel slope (61 mV dec-1) for mesoporous cobalt tungsten oxide hydroxide, while the cobalt tungstate nanoparticles cannot satisfy the basic demand of electrocatalysts. Herein, rational phase transformation and morphology design can significantly affect the property of oxygen evolution, which can provide vast opportunities to turn into candidates for the novel oxygen evolution catalyst.