Efficient Noble‐Metal‐Free Integration Electrolysis for Solar H2 and Supercapacitor Electrode Coproduction in Acidic Water

Abstract Solar driven proton exchange membrane water electrolysis (PEMWE) is of great promise for stable and high‐purity H 2 production, but often limited by the serious partial loading issue due to the intermittent nature of solar energy, the kinetically sluggish oxygen evolution reaction (OER) and the usage of noble metal‐based anodes (e. g., Pt, Ir, and Ru). Herein, we report an efficient integrated water electrolysis by replacing OER with favorable pyrrole electrooxidation polymerization for H 2 generation in acidic solutions, wherein nonprecious Co 2 P and carbon cloth (CC) served as cathode and anode, respectively. A voltage of only 1.0 V was needed to afford 10 mA cm −2 , 590 mV smaller than that in traditional PEMWE based on noble Pt/C@RuO 2 benchmark couple. Moreover, simple carbonization of the resulting polypyrrole/CC at anode yielded a supercapacitor electrode with a high specific capacitance of 290 F g −1 at 1 A g −1 and robust stability, which then functioned as energy reservoir to alleviate the partial loading issue for coproduction of solar H 2 and supercapacitor electrode.