g‐C₃N₄‐Based Heterostructured Photocatalysts

TLDR

Photocatalysis offers a promising route to address energy and environmental crises by harnessing solar energy, and graphitic carbon nitride (g‑C3N4) has attracted attention for its visible‑light activity, low‑cost synthesis, chemical stability, and layered structure, yet its pure form suffers from poor charge‑carrier separation and low activity, prompting the development of heterostructures—such as type II, Z‑scheme, p‑n, metal, and carbon variants—that enhance charge separation and photocatalytic performance. This review aims to summarize recent progress in designing g‑C3N4‑based heterostructured photocatalysts and elucidating their unique charge‑carrier separation and transfer mechanisms. The authors examine design strategies and charge‑carrier transfer mechanisms of these heterostructures, and evaluate their applications in water splitting, CO₂ reduction, and pollutant degradation. They conclude with remarks and perspectives on the challenges and opportunities for advancing g‑C3N4‑based heterostructured photocatalysts.

Abstract

Abstract Photocatalysis is considered as one of the promising routes to solve the energy and environmental crises by utilizing solar energy. Graphitic carbon nitride (g‐C 3 N 4 ) has attracted worldwide attention due to its visible‐light activity, facile synthesis from low‐cost materials, chemical stability, and unique layered structure. However, the pure g‐C 3 N 4 photocatalyst still suffers from its low separation efficiency of photogenerated charge carriers, which results in unsatisfactory photocatalytic activity. Recently, g‐C 3 N 4 ‐based heterostructures have become research hotspots for their greatly enhanced charge carrier separation efficiency and photocatalytic performance. According to the different transfer mechanisms of photogenerated charge carriers between g‐C 3 N 4 and the coupled components, the g‐C 3 N 4 ‐based heterostructured photocatalysts can be divided into the following categories: g‐C 3 N 4 ‐based conventional type II heterojunction, g‐C 3 N 4 ‐based Z‐scheme heterojunction, g‐C 3 N 4 ‐based p–n heterojunction, g‐C 3 N 4 /metal heterostructure, and g‐C 3 N 4 /carbon heterostructure. This review summarizes the recent significant progress on the design of g‐C 3 N 4 ‐based heterostructured photocatalysts and their special separation/transfer mechanisms of photogenerated charge carriers. Moreover, their applications in environmental and energy fields, e.g., water splitting, carbon dioxide reduction, and degradation of pollutants, are also reviewed. Finally, some concluding remarks and perspectives on the challenges and opportunities for exploring advanced g‐C 3 N 4 ‐based heterostructured photocatalysts are presented.