Defects engineering of one-step phosphorus sulphide NiFe PBA as bifunctional electrocatalyst for boosting water splitting

Abstract

Electrolysis water is a key technology for solving energy problems, where water is broken down into oxygen and hydrogen under power on. In the process of water electrolysis, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) break out at the cathode and anode, respectively. Hydrogen is a renewable and clean energy needed in today's society. Due to the limitation of reaction kinetics, catalysts are needed to reduce the reaction energy barrier. In this study, phosphorus-sulfurized and etched NiFe Prussian blue analogues (NiFe ePBA-P/S) with low cost and high catalytic performance was prepared as a bifunctional catalyst by a facile method for water splitting. The hollow structure of NiFe ePBA-P/S provides sufficient channels to release hydrogen and oxygen bubbles. The accession of P and S elements into the catalysts can enhance the electron transfer efficiency and obtain higher performance. Thanks to the abundance of defects, NiFe ePBA-P/S materials only require 311 (HER) and 310 (OER) mV overpotentials at 100 mA cm^-2, respectively, with stably processing for 100 h.