Comparison of physiochemical properties and photodegradation activities among different divalent transitiion metal tungstate nanoparticles at different calcined temperatures

Various metal oxide, compound oxides and metal tungstate nanoparticles have many unique physical, chemical and electronic properties which allow them to act as a semiconductor. Many synthetic materials and chemicals are produced and used by human civilization, are left in the environment after serving their purpose and thus remain in nature for a long time. Most of these wastes are not naturally degradable and keep causing environmental pollution. As nanoparticles have semiconductor properties, due to their suitable band energy, stability and optical properties they are widely used in electronics such as IC, LED, solar cells, signaling and molecular switching etc. Metal Tungstates have been of scientific interest among researchers for the last couple of decades to explore its properties and functions in various applications like photocatalysis in water splitting or in organic molecule degradation. Ball State University also has a strong group of researchers who synthesize various semiconductor nanoparticles and study their properties and applications extensively. In this project we have synthesized four different metal nanoparticles (CoWO4, NiWO4, CuWO4, and ZnWO4) following coprecipitation method, calcined them at four different temperatures (450°C, 550°C, 650°C and 750°C), different physiochemical properties were studied and compared. Finally, the calcined nanoparticles were deployed in methylene blue, an organic dye degradation under controlled light source to assess their photocatalytic activity.