Surface Engineering of Carbon Nitride Electrode by Molecular Cobalt Species and Their Photoelectrochemical Application.

Graphitic carbon nitride (CN) has been widely regarded as a promising photocatalyst since the discovery of its capability for photocatalytic hydrogen evolution. Herein, we developed a functional CN film on a conductive fluorine-doped tin oxide (FTO) electrode by using a microprinting-based direct growth method. Furthermore, the photoelectrochemical performance of the derived CN@FTO film was demonstrated to be enhanced by incorporating molecular cobalt species. The reduced charge transport resistance in the cobalt-modified CN@FTO films is suggested to accelerate the charge-carrier transfer rate and thus to improve the performance in photoelectrochemical application. The approach is versatile and can be further optimized by selecting a proper "ink" solution and modifier on various conductive substrates.