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

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 Co2P 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@RuO2 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.