Tungsten Based Photocatalyst for Visible Light Degradation of Organic Pollutants

Abstract

Aquatic environments are continuously contaminated by human activities that involve the release of organic pollutants such as phenolic compounds, dyes, petroleum surfactants, etc. Conventional Water treatment systems such as absorption, coagulation, and biological systems for degradation of organic pollutants are quite complex and only shift the pollutants from one phase to another. Therefore, further waste is generated, which needs proper handling, treatment, and discharge as well. This requires the search for a cost-effective, simple, and cleaner solution for the complete removal of pollutants to enhance the quality of water. Degradation of organic pollutants by photocatalysis is one of the most efficient solutions among these techniques. Photocatalysis uses sunlight as an energy source to completely mineralize the impurities at photocatalytic surfaces. The present research focuses on the development of an efficient photocatalytic system using copper tungstate, graphene quantum dots, and their nanocomposite. The study was performed in three steps. In the first step, the preparation of photocatalyst and nanocomposite takes place, including pure copper tungstate (CuWO4), graphene quantum dots (GQDs), and a series of composites of CuWO4/GQDs with varying content of CuWO4 namely 0.3GCW, 0.5GCW, 0.7GCW. In the second step, the prepared catalysts were analyzed by several characterization techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Photoluminescence (PL), Raman spectra, and UV-visible absorption, and lastly, the photocatalytic activity of prepared photocatalysts was evaluated. To evaluate the photocatalytic performance, the synthesized photocatalysts were used to degrade phenol. The results showed that the photocatalytic activity of 0.5GCW was superior to others, which was 53.4 1%. After observation, it is concluded that the activity of prepared photocatalysts increases by order of 0.5GCW > 0.7GCW>0.3GCW > CuWO4.