Photo and redox active carbon nitride – dual functionality for energy storage

Abstract

The ability to directly capture and store solar energy in an electrical form within a single structure is an intriguing concept and if feasible, could be an ideal approach to overcome the intermittency issue of solar energy. Recently, ionothermal-treated carbon nitride has shown this unique dual functionality. However, the current understanding of the distinctive material is minimal and as such, presented here are data that give insight into how the dual function can be viably modulated without in fact altering the structure. Importantly, it has been shown that there is redox behavior in ionic carbon nitrides thus providing impetus for battery-like storage capability. Furthermore, the work demonstrates that by simply altering either the ions or the pH of the electrolyte, both the potential and storage capability of the photo-excited electron can be augmented. The former can be modulated over ca. 700 mV and the latter can be increased 4 times when Na ions are replaced by K ions. This work provides insight into ionic carbon nitrides and their seminal properties that have thus far not been realized in other conventional semiconductors.