Hydrovoltaic effect-enhanced photocatalysis by polyacrylic acid/cobaltous oxide-nitrogen doped carbon system for efficient photocatalytic water splitting.

Severe carrier recombination and the slow kinetics of water splitting for photocatalysts hamper their efficient application. Herein, we propose a hydrovoltaic effect-enhanced photocatalytic system in which polyacrylic acid (PAA) and cobaltous oxide (CoO)-nitrogen doped carbon (NC) achieve an enhanced hydrovoltaic effect and CoO-NC acts as a photocatalyst to generate H and HO products simultaneously. In this system, called PAA/CoO-NC, the Schottky barrier height between CoO and the NC interface decreases by 33% due to the hydrovoltaic effect. Moreover, the hydrovoltaic effect induced by H carrier diffusion in the system generates a strong interaction between H ions and the reaction centers of PAA/CoO-NC, improving the kinetics of water splitting in electron transport and species reaction. PAA/CoO-NC exhibits excellent photocatalytic performance, with H and HO production rates of 48.4 and 20.4 mmol g h, respectively, paving a new way for efficient photocatalyst system construction.