Acid-modulated porous AgI/D-MIL-53(Fe) composites for the removal of antibiotic contaminant

In the MOFs-based composites, the co-catalyst nanoparticles loads tend to agglomerate. In the self-assembly process of MOFs-based composites, the use of acid modulators solved the accumulation of AgI nanoparticles cocatalyst. The active sites of carboxyl groups and mesoporous structure brought by acid modulator provide more loading sites for AgI nanoparticles. The novel AgI/D-MIL-53(Fe) showed good adsorption and photocatalytic performance in the process of removing tetracycline pollutants. Compared to the degradation efficiency of the MIL-53(Fe) with 50.8%, it of AgI/MIL-53(Fe) increased to 85.1% and which further increased to 96.2% by AgI/D-MIL-53(Fe) based on the HCl modulator. On the one hand, it is beneficial for the mesoporous D-MIL-53(Fe) modulated by HCl modulator to disperse the AgI nanoparticles co-catalyst. On the other hand, AgI nanoparticles, as a photosensitive agent, adsorb visible light to generate photogenerated electrons and holes, and electrons rapidly transferred to the heterojunction bridge Ag0 and then captured by the holes from the D-MIL-53(Fe). The construction of AgI/D-MIL-53(Fe) Z-scheme heterojunction provided favorable conditions for the rapid separation and photogenerated electrons and holes. Finally, ·O2−, ·OH and h+ as the main active free radicals were driving forces. This study provided more possibilities and opportunities for the construction of mesoporous MOFs-based composites.