Solar-driven water splitting with ascorbic acid oxidation for efficient hydrogen production

Abstract

Here, we present a solar-driven water splitting system using Fe_0.5Ni_0.5@CN as a catalyst in the anode, replacing the oxygen evolution reaction (OER) with the ascorbic acid oxidation reaction (AAOR). The bimetallic catalyst enhances electron transfer and lowers reaction barriers through Fe–N₄ and Ni–N₄ coordination sites, with C–N bonds further promoting the AAOR, exhibiting near 100% Faraday efficiency over 500 h. The system, coupled with commercial silicon-based solar cells, exhibits a solar-to-chemical energy efficiency of 10.11%. The AAOR lowers the anode potential from 1.6 V to 0.5 V, reducing hydrogen production energy by 75% compared to the OER. Moreover, the anode product, dehydroascorbic acid (DHA), has a significant economic value (AA ∼ 0.0143 USD per g, DHA ∼ 251.72 USD per g) and enhances system safety by eliminating gaseous products. Biological tests show that the device's anode reaction solution (containing DHA and AA) inhibits tumor cell growth by 98.7% after 48 hours, highlighting its pharmaceutical potential. This study offers a safe, efficient, and economically viable method for hydrogen production and valuable chemical synthesis.