Synthesis, characterization of nanosized ZnCr2O4 and its photocatalytic performance in the degradation of humic acid from drinking water

Abstract

Zinc chromite (ZnCr2 O4) has been synthesized by the thermolysis of a new Zn(II)-Cr(III) oxalate coordination compound, namely [Cr2 Zn(C2 O4)4 (OH2)6]·4H2 O. The coordination compound has been characterized by chemical analysis, infrared spectroscopy (IR), and thermal analysis. The zinc chromite obtained after a heating treatment of the coordination compound at 450ºC for 1 h has been investigated by XRD, FE-SEM, TEM/HR-TEM coupled with selected area electron diffraction (SAED) measurements. The photocatalytic performance of nanosized zinc chromite was assessed for the degradation and mineralization of humic acid (HA) from a drinking water source, envisaging the development of the advanced oxidation process for drinking water treatment technology. A mineralization efficiency of 60% was achieved after 180 min of 50 mg L−1 HA photocatalysis using zinc chromite under UV irradiation, in comparison with 7% efficiency reached by photolysis.