Bioinspired Ultralow-Potential Phosphite Electrooxidation Drives Tandem of Bipolar Hydrogen Production and Refractory Wastewater Upgrading

Inspired by natural enzymes, an innovative phosphite-driven bipolar hydrogen production (BHP) system was successfully constructed. The well-designed Cu-Rh-P 1 N 5 catalytic sites endow the phosphite oxidation process with the synchronous realization of ultralow onset potential (–0.32 V vs RHE) and anodic hydrogen release. On this basis, by optimizing the Cu-Rh-P 1 N 5 anode into a three-dimensional layered structure, the as-assembled BHP system exhibits an industrial-level current density of 500 mA cm −2 with just 0.24 V voltage input and operates stably for over 1200 h to enable tandem of BHP, phosphite wastewater purification, and valuable phosphate production. Meanwhile, under such harsh conditions, the Faraday efficiencies of H 2 production and phosphite upgrading are maintained close to 200 and 100%, respectively. Additionally, the electricity cost is just US $0.47/kg of H 2, far exceeding the 2031 U.S. DOE target. Such development provides a new paradigm for BHP system and holds vast potential in valuable chemical production and hard-to-abate sector decarbonization.