Recent progress in g-C3N4 based low cost photocatalytic system: Activity enhancement and emerging applications

Abstract

Graphitic C3N4 (g-C3N4) has continuously attracted attention since it was reported as a metal-free semiconductor for water splitting. However, its ability to evolve hydrogen from water is significantly dependent on the use of noble metal co-catalyst, mainly Pt. In recent years, good progress has been achieved in developing co-catalysts containing earth abundant elements only for constructing low cost and efficient g-C3N4 based photocatalytic systems. Besides, exfoliation of bulk g-C3N4 into two dimensional g-C3N4 nanosheets offers large surface area and exposed active sites, which are beneficial for activity enhancement. Furthermore, oxygen evolution and CO2 photoreduction over g-C3N4 have gained increasing interests due to the demand to achieve overall water splitting and conversion of CO2 into chemicals and fuels. In this mini-review, we will briefly summarize the latest research works on g-C3N4 based photocatalytic systems during the last three years with emphasis on the progress achieved in enhancing the hydrogen evolution activity of g-C3N4 by loading noble metal free co-catalysts, exfoliating bulk g-C3N4 into nanosheets, and applying the g-C3N4 system in photocatalytic O2 evolution and CO2 reduction.