Electrolyte modification method induced atomic arrangement in FeOx/NF nanosheets for efficient overall water splitting.

Abstract

To explore transition metal-based electrocatalysts with remarkable energy storage and conversion performance, the rational design and synthesis of electrodes with rich active sites and favorable electrical conductivity are crucial. Herein, using fluoroethylene carbonate (FEC) additive in electrochemical conversion reaction (electrolyte modification method) is proposed as an effective strategy to enhance the catalytic activity of FeOx/NF. The optimal sample FeOx/NF-Li-FEC1 shows optimized HER activity with remarkably low overpotential of 222 mV at a current density of 200 mA cm-2. By employing FeOx/NF-Li-FEC1 as bifunctional electrocatalysts, the overall water-splitting device reaches a current density of 10 mA cm-2 at a low cell voltage of 1.56 V. The outstanding performance is mainly attributed to the atomic arrangement to offer rich active sites as well as the evolved electronic structure and the thin SEI layer to accelerate charge transfer process. This study opens up a novel avenue to rationally design and synthesize low-cost and high-performance electrode materials for electrochemical energy conversion and storage devices.