Significantly Enhanced Energy‐Saving H₂ Production Coupled with Urea Oxidation by Low‐ and Non‐Pt Anchored on NiS‐Based Conductive Nanofibers

Abstract

Rational designing electrocatalysts is of great significance for realizing high‐efficiency H₂ production in the water splitting process. Generally, reducing the usage of precious metals and developing low‐potential nucleophiles oxidation reaction to replace anodic oxygen evolution reaction (OER) are efficient strategies to promote H₂ generation. Here, NiS‐coated nickel–carbon nanofibers (NiS@Ni‐CNFs) are prepared for low‐content Pt deposition (Pt‐NiS@Ni‐CNFs) to attain the alkaline HER catalyst. Due to the reconfiguration of NiS phase and synergistic effect between Pt and nickel sulfides, the Pt‐NiS@Ni‐CNFs catalyst shows a high mass activity of 2.74‐fold of benchmark Pt/C sample. In addition, the NiS@Ni‐CNFs catalyst performs a superior urea oxidation reaction (UOR) activity with the potential of 1.366 V versus reversible hydrogen electrode (RHE) at 10 mA cm⁻², which demonstrates the great potential in the replacement of OER. Thus, a urea‐assisted water splitting electrolyzer of Pt‐NiS@Ni‐CNFs (cathode)||NiS@Ni‐CNFs (anode) is constructed to exhibit small voltages of 1.44 and 1.65 V to reach 10 and 100 mA cm⁻², which is much lower than its overall water splitting process, and presents a 6.5‐fold hydrogen production rate enhancement. This work offers great opportunity to design new catalysts toward urea‐assisted water splitting with significantly promoted hydrogen productivity and reduced energy consumption.