A comprehensive review on graphene-/graphitic carbon nitride-based MOFs for the photocatalytic purification of dye wastewater

The development of advanced porous functional materials with enhanced photocatalytic performance for the degradation of hazardous pollutants such as dyes has led to the emergence of graphene-/graphitic carbon nitride-based metal–organic frameworks (GBMOFs) as promising photocatalysts. This study aims to comprehensively review advances in GBMOFs for the photocatalytic degradation of dye pollutants. As part of the study objective, the photocatalytic performance, recyclability, and stability dynamics of GBMOFs were critically reviewed to identify patterns and key trends. Emerging trends and technology readiness levels were succinctly discussed to assess the industrial applicability of GBMOF photocatalytic systems for dye remediation. Interestingly, the findings revealed that most GBMOF systems can deliver >80% degradation efficiency at pH 3–13 and doses of 2–1000 mg in 3–390 minutes. A predominant operational trend involving ˙OH and ˙O₂⁻ was also noticed. Furthermore, the study shows that GBMOFs can be recycled 3–30 times while maintaining >70% of their original degradation performance and morphology in most of the cases. Recent advances and emerging trends include the application of p–n–p heterojunctions, ternary GBMOFs (which outperformed binary counterparts), piezo and sono-assisted photocatalysis, the use of natural sunlight, oxygen vacancies, and defect engineering. Finally, future perspectives are presented to establish a clear framework for guiding the future design of highly efficient, stable, practical, and enhanced GBMOF photocatalytic systems for the remediation of various dyes and pollutants.