Unlocking the Potential of Carbon Nitride (C_xN_y) Electrocatalysts in Hydrogen Evolution, Oxygen Evolution and Overall Water Splitting

Abstract

Electrocatalytic water splitting with carbon nitride (C_xN_y) materials has gained significant interest, driven by extensive research validating their synthesis, structure, and applications. Among various C_xN_y stoichiometric ratios, graphitic carbon nitride (g-C₃N₄) stands out as the most stable configuration and is extensively studied in the literature. However, other C_xN_y structures like g-CN, C₂N, C₃N₅, and C₉N₄ have been booming recently as well by exploration of their greatness. Recent progress of C_xN_y-based electrocatalysts in hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting (OWS) has been examined meticulously. More emphasis has been placed on exploring the synthesis-structure-performance and simulate-structure-performance relationships of C_xN_y electrocatalysts in experimental and computational studies, respectively. This review outlines a clear framework for unifunctional C_xN_y electrocatalysts in HER and OER, focusing on recent advancements in (1) defect engineering, (2) structural engineering, and (3) hybridization. The research on bifunctional C_xN_y electrocatalysts is highlighted and explored through two main approaches: intrinsic and extrinsic modifications. Finally, the strategies and perspectives for creating novel highly efficient C_xN_y electrocatalysts for HER, OER, and OWS are analyzed. This review aims to inspire researchers to incorporate computational methods into experimental studies for developing highly efficient bifunctional C_xN_y-based electrocatalysts.

Keywords

carbon nitride / electrocatalysis / water splitting

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