Surface Modified Layered Iron Vanadate As Bifunctional Electrocatalyst for Overall Water Splitting

摘要

Electrocatalysis water splitting is an attractive method to generate hydrogen from water. To date, the state-of-the-art catalysts to split water are based on noble metal, such as platinum for hydrogen evolution reaction (HER) and IrO_2 and RuO_2 for oxygen evolution reaction (OER). However, their scarcity and high cost limit the application. Therefore, great efforts have been devoted to explore highly active and cost effective catalyst materials. Recently, noble-metal free Fe-based catalysts have been demonstrated to be highly efficient for OER. It would then be a great advance if such Fe-based catalysts can become bifunctional for overall water splitting. In this work, surface modification of layered iron vanadate was performed to serve this purpose. The surface modification provides and protects additional electrochemical active sites during the reaction. Remarkably, the surface modified iron vanadate exhibits excellent activity for HER and OER, and hence great overall water splitting performance is demonstrated. This discovery not only provides a novel, low-cost, and efficient electocatalyst, but also expands the scope of non-precious metal elements for overall water splitting.