Synthesis of the Highly Efficient Catalysts CdZnS@MIL-53(Fe) and ZnS@MIL-53(Fe) and Their Thermally Decomposed Derivative for Electrochemical OER Activity and Photodegradation of Rhodamine B Dye

The development of a highly efficient catalyst for water splitting and photodegradation of organic dyes has become the focus of a considerable number of research groups. In the work described here CdZnS@MIL-53(Fe) and ZnS@MIL-53(Fe) were synthesized by the solvothermal method and subjected to thermal degradation at 520 °C in an oxidative environment to obtain CdZnS/Fe2O3 and ZnS/Fe2O3, respectively. Electrocatalytic activity for the oxygen evolution reaction is analyzed via cyclic voltammetry and linear sweep voltammetry. It was found that CdZnS@MIL-53(Fe) shows maximum catalytic activity for the oxygen evolution reaction and delivers 10 mAcm−2 current density at 95 mV overpotential as compared to MIL-53(Fe)/NF (210 mV) and ZnS@MIL-53(Fe)/NF (112 mV). Similarly, the derivative of it, CdZnS/Fe2O3, shows maximum catalytic activity for the oxygen evolution reaction and delivers 10 mAcm−2 current density at 90 mV overpotential as compared to Fe2O3 (204 mV) and ZnS/Fe2O3 (115 mV). Based on these results, it is evident that these materials are highly efficient for OER activity compared with other materials in literature. Similarly, CdZnS/Fe2O3 shows maximum photocatalytic activity for the photodegradation of Rhodamine B, up to 75% compared to CdZnS@MIL-53(Fe), which degrades up to 51% of the dye. The synthesized materials were characterized by powdered X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. Based on these results the aim is to develop more MOF-based materials and their derivatives by simple heat treatment and to implement them in different catalytic applications.