Bimetallic MOF derived ZnCo2O4 nanocages as a novel class of high performance photocatalyst for the removal of organic pollutants

Abstract

• ZnCo-MOF derived ZnCo 2 O 4 nanocages was facilely synthesized with the help of a hydrothermal technique. • The kinetic studies exhibited the 84.3, 87.9, and 89.5% of degradation of CV, MB, and RhB dye pollutants after the 180 min of irradiation at the rate constants (k) of 0.010, 0.011, and 0.012 min −1 , respectively. • The ZnCo 2 O 4 nanocages delivered the highest photocatalytic degradation percentage for RhB than other organic dye pollutants. • The extensive role of photogenerated holes and hydroxide radicals affecting to the dye degradation phenomena is confirmed by radical scavenger trapping experiments. Synthesis of metal oxides from Metal organic frameworks (MOFs) has taken center stage in the recent years due to its excellent structural behavior. Many MOF derived metal oxides such as ZnO, NiO, Co 3 O 4 , CuO, NiCo 2 O 4 , and CoFe 2 O 4 , etc., has been successfully synthesized using MOFs as templates. In this report, we have adopted the MOF assisted method to prepare ZnCo 2 O 4 (abbreviated as ZCO) nanocages using hydrothermal method were utilized to explore the photocatalytic removal of various organic contaminants like Methylene Blue (MB), Rhodamine B (RhB), and Crystal Violet (CV). The ZCO nanocages has been investigated to evaluate the structural properties by X-ray diffraction (XRD) studies. Morphological, microstructural, chemical compositional and optical characterizations have been carried out using FESEM, TEM, EDS, XPS, and UV–Visible spectrophotometer, respectively. The specific surface area and pore size of ZCO nanocages were confirmed from nitrogen adsorption and desorption isotherm analysis. Further, ZCO nanocages were utilized to explore the photocatalytic removal of various organic contaminants like MB, RhB, and CV. Moreover, ZCO nanocages showed remarkable photocatalytic performance for the removal of different dye pollutants. The kinetic studies exhibited the 84.3, 87.9, and 89.5% of removal of CV, MB, and RhB dye pollutants after the 180 min of irradiation at the 0.010, 0.011, and 0.012 min −1 rate constants (k), respectively. The extensive role of hydroxide radicals and photogenerated holes affecting to the organic pollutant degradation mechanism is studied by radical scavenger trapping experiments. In addition, its recyclability was also confirmed from stability study. Therefore, the present investigations offer a way to develop a MOF derived metal oxide for photocatalytic removal of various organic pollutants.