Graphitic carbon nitride (g-C3N4) electrodes for energy conversion and storage: a review on photoelectrochemical water splitting, solar cells and supercapacitors

Abstract

Graphitic carbon nitride (g-C₃N₄) has emerged as one of the most promising photocatalysts due to its metal-free nature, abundance of raw material, and thermal physical–chemical stability. The breakthrough research studies in recent years have mostly been concentrated on the engineering of the intrinsic and morphological properties of g-C₃N₄-based photocatalysts in the framework of powder suspensions for artificial photosynthesis and environmental remediation. However, practical applications of g-C₃N₄-based electrodes and devices are still in the early stages of development due to challenging fabrication methods of g-C₃N₄ thin films. This review addresses the classification of diverse techniques to deposit g-C₃N₄-based thin films and explores a broad spectrum of applications pertinent to g-C₃N₄-based electrodes. Although this paper is principally focused on photoelectrochemical water splitting, other emerging applications of g-C₃N₄ in solar cells, electrocatalysts and supercapacitors are also reviewed. Lastly, further suggestions are posited for other potential applications, challenges and future orientations.