Amorphous CoV Phosphate Nanosheets as Efficient Oxygen Evolution Electrocatalyst

Abstract

The oxygen evolution reaction (OER) is crucial for hydrogen production. However, OER with four-electron transfer requires electrocatalysts to speed up its sluggish kinetics in alkaline solutions. Herein, amorphous CoV phosphate (denoted as CoVÀ Pi) nanosheets synthesized by a straightforward one-step hydrothermal approach is reported, which provide a low overpotential of 320 mV at 10 mA cm À 2 , a small Tafel slope down to 48.8 mV dec À 1 and long-term durability over 80 h. The efficient activity is ascribed to the amorphous nanosheets structure, high electrochemically active surface area, enhanced surface wettability and the synergistic effect of the active metal atoms. This study significantly indicates that CoVÀ Pi is a promising alternative to replace expensive noble metal-based catalysts for electrochemical water splitting.

Design of earth‐abundant amorphous transition metal‐based catalysts for electrooxidation of small molecules: Advances and perspectives

“…To achieve an excellent ESM activity, endowing catalysts with architectural merits like high surface area and rational pore hierarchy is a sound option. In this context, porous 2D nanosheets, 203 3D nanostructures, 204 and hierarchical nanostructures 63 are preferred choices. Starting from 2D Co phosphonate organic frameworks, Guo et al.…”

“…To achieve an excellent ESM activity, endowing catalysts with architectural merits like high surface area and rational pore hierarchy is a sound option. In this context, porous 2D nanosheets, 203 3D nanostructures, 204 and hierarchical nanostructures 63 205 The porous structure provides the amorphous Co phosphate with a large free space, increased the distribution of electroactive centers, and facilitated hydroxide diffusion during the OER process. Similarly, in a microporous 2D NiCoFe phosphate nanosheet catalyst, the microporous confinement in a 2D orientation would decrease the resistance of mass transport, enlarge the ECSA, and enhance the diffusion of O 2 products.…”