Structural-interfacial engineering of MOF-functionalized aerogels for efficient photocatalytic reduction of Cr(VI)

Hexavalent chromium (Cr(VI)) contamination poses severe ecological risks due to its carcinogenicity and prevalence in industrial wastewater, where metal-organic frameworks (MOFs) show photocatalytic remediation potential. However, powdered MOFs suffer from poor recyclability and secondary pollution risks in practical applications. This study proposes an integrated structural-interfacial engineering strategy that combines the design of a robust three-dimensional fiber network framework with the interfacial engineering of MOFs and cellulose nanofibers to fabricate robust MOF-functionalized aerogel (MOFA) photocatalyst. The MOFAs feature hierarchical coordination effects enabling precise MOF crystallization control, achieving ultrahigh MOF loading (76.77 wt%), mechanical robustness (29 kPa stress at 70 % compression), exceptional stability (6.7 % permanent deformation after 100 cycles), and enhanced photocatalytic activity (photocurrent density of 2.87 μA/cm²). The optimized interfacial structure delivers superior adsorption (67 %) and photocatalytic performance (100 % Cr(VI) reduction in 80 min, > 94 % efficiency retention after 5 cycles), validated across diverse water matrices including high-salinity tanning wastewater under outdoor conditions. This innovative strategy offers a new design approach for developing high-performance photocatalytic materials and holds important application prospects in environmental governance.