Abstract

Photocatalysis represents a promising technology that might alleviate the current environmental crisis. One of the most representative photocatalysts is graphitic carbon nitride (g-C₃N₄) due to its stability, cost-effectiveness, facile synthesis procedure, and absorption properties in visible light. Nevertheless, pristine g-C₃N₄ still exhibits low photoactivity due to the rapid recombination of photo-induced electron-hole (e⁻-h⁺) pairs. To solve this drawback, Z-scheme photocatalysts based on g-C₃N₄ are superior alternatives since these systems present the same band configuration but follow a different charge carrier recombination mechanism. To contextualize the topic, the main drawbacks of using g-C₃N₄ as a photocatalyst in environmental applications are mentioned in this review. Then, the basic concepts of the Z-scheme and the synthesis and characterization of the Z-scheme based on g-C₃N₄ are addressed to obtain novel systems with suitable photocatalytic activity in environmental applications (pollutant abatement, H₂ production, and CO₂ reduction). Focusing on the applications of the Z-scheme based on g-C₃N₄, the most representative examples of these systems are referred to, analyzed, and commented on in the main text. To conclude this review, an outlook of the future challenges and prospects of g-C₃N₄-based Z-scheme photocatalysts is addressed.