W/Ni 3(PO 4) 2@NC/NF Nanorods via Electrodeposition with Carbonization as a Bifunctional Catalyst for Electrocatalytic Water Splitting

Abstract

Conducting polymers are commonly used as precursors for preparing carbon-based catalysts and have been used in electrocatalytic water splitting. However, so far, most of the catalytic materials synthesized with the assistance of high polymer conducting polymers are non-self-supporting and have only single-function catalytic effect. Therefore, it is an inevitable trend to synthesize a bifunctional self-supported highly efficient and long-stable water splitting catalyst. Herein, a self-supporting polypyrrole precursor PPy-PW12 was prepared by electrodeposition with phosphotungstic acid as dopant. In addition, the PPy-PW12 precursor was then calcined. The as-prepared W/Ni3(PO4)2@NC/NF electrocatalyst exhibits admirable HER and OER performances with overpotentials of 48 mV for HER and 236 mV for OER to reach a current density of 10 mA cm -2 in 1M KOH solution. Additionally, when W/Ni3(PO4)2@NC/NF is used in overall water splitting as a bifunctional catalyst, it needs only 1.53 V to give a current density of 10 mA cm−2 which is superior to typically integrated Pt/C and RuO2 counterparts. Our work offers a facile strategy to apply W/Ni3(PO4)2@NC/NF as practical bifunctional electrocatalysts for large-scale water splitting.