Rational construction of hierarchical porous FeP nanorod arrays encapsulated in polypyrrole for efficient and durable hydrogen evolution reaction

Abstract Employing an environmentally friendly and economical approach to significantly improve the electrocatalytic activity for hydrogen evolution reaction (HER) has attracted widespread attention because of its enormous value and challenge. Herein, we report a series of FeP nanorod arrays (FeP NRAs) with polypyrrole (PPy) shell coating on carbon textiles (CTs) to improve the HER performance. The composite combines the high conductivity of PPy and synergistic effect between FeP and PPy, where the PPy coating remarkably reduces the apparent activation energy for HER and increases the turnover frequency of catalysts, thus the electrocatalytic performance of FeP@PPy/CTs hybrid nanorod arrays is significantly improved. Among them, the FeP@PPy/CTs-5 h catalyst exhibit superior HER performance with a low onset over-potential of 103.1 mV and a small Tafel slope of 49.2 mV/dec at 10 mA cm−2, and as well as an excellent long-term stability during operation for 46 h. Notably, it shows efficient HER performance during various bending status, demonstrating that the stability and flexibility of FeP@PPy/CTs catalysts. The excellent electrocatalytic performance is promising for applications as a cost-effective non-noble-metal HER catalyst during electrochemical water splitting for large-scale hydrogen fuel production.