Solar-driven advanced oxidation process catalyzed by metal-organic frameworks for water depollution

Abstract

Phosphonate-based MOF materials namely, STA-12(M) (M = Mn, Fe, Co, Ni), show photocatalytic activity for the degradation of methylene blue (MB) and methyl Orange (MO) from aqueous solution under natural sunlight irradiation. Thus, photo-Fenton oxidative discoloration of dyes have been surveyed by H2O2 catalyzed with the STA-12(M). The degradation of the dyes, appears to be faster with STA-12(Fe) than other synthesized MOFs. The reaction is first order with respect to MO and MB dyes and the synergistic index in the STA-12(Fe)/sunlight/H2O2system reached as high as 431%. Mineralization of dyes was discussed by spectroscopic and TOC measurement. Besides, the efficiency of STA-12(Fe) used in photo- Fenton process was attentively investigated through the characterization of reactive radicals, the stability and reusability of the photocatalyst, also the effect of operational parameters such as H2O2 dosage, solution pH and initial dye concentration. This work demonstrates the first example of facilitating photo- Fenton excitation of H2O2 via phosphonate based metal organic frameworks as photocatalysts and explained a new opportunity for sunlight-induced photocatalytic environmental remediation and protection.