Carbon nitride photoelectrode prepared via a combined strategy of electrophoresis and vapor deposition

Abstract

Photoelectrochemical water splitting converts solar energy into clean hydrogen fuel. In this system, the preparation of high-quality photoanode is essential for achieving efficient solar hydrolysis. Polymeric carbon nitride has emerged as a promising photocatalyst for solar water splitting due to its visible light absorption, suitable band edge positions and good chemical stability. However, considerable difficulties have been encountered for the preparation of robust and well-bonded carbon nitride films on conductive substrates. Herein, a combined strategy of electrophoresis and vapor deposition results in robust and high performing carbon nitride film photoelectrodes with good bonding on substrates, suitable thickness for light absorption, and enhanced charge separation and transfer abilities. The unique structure of the photoanode thus facilitates the oxidation of water and leads to an optimal photocurrent density of approximately 120 μA cm-2 at 1.23 VRHE. This work provides new insights for the preparation of polymeric carbon nitride film photoelectrodes, promoting the developments of photoelectric and photoelectrochemical applications based on carbon nitride.