W/Ni3(PO4)2@NC/NF nanorods via electrodeposition with carbonization as a bifunctional catalyst for electrocatalytic water splitting

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 a 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-PW 12 was prepared by electrodeposition with phosphotungstic acid as a dopant. In addition, the PPy-PW 12 precursor was then calcined. The as-prepared W/Ni 3 (PO 4 ) 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 1.0 M KOH solution. Additionally, when W/Ni 3 (PO 4 ) 2 @NC/NF is used in overall water splitting as a bifunctional catalyst, it needs only 1.53 V to deliver a current density of 10 mA cm −2 , which is superior to typically integrated Pt/C and RuO 2 counterparts. Our work offers a facile strategy to apply W/Ni 3 (PO 4 ) 2 @NC/NF as practical bifunctional electrocatalysts for large-scale water splitting.