Synthesis and characterization of visible light active photocatalysts by solgel method / Elvana Nerissa Mohamad

In the present study, synthesis and characterization of visible-light active photocatalysts needed for the photodegradation of organic pollutants was presented. Non metals like N,C and F were doped with titanium dioxide by solgel method. The effects of dopant concentration, calcination temperature, dopant element and titanium precursor on the synthesis were studied systematically. The photocatalytic activities of the surface modified titanium dioxide were tested using 10 ppm methylene blue solution. The properties were characterized by using XRD, UV-vis DRS, FESEM, BET and XPS analysis. Dopant concentration, calcination temperature, dopant element and titanium precursors gave significant effect on the properties of the photocatalysts and photocatalytic activity. Dopant concentration of 0.75% and calcination temperature of 600°C yielded the highest photocatalytic degradation efficiency as high as 91.3%. Each dopant element showed different crystal structure and properties of the photocatalysts. A combination of two elements (N-C codoped TiOi) showed the best performance. Titanium tetraisopropoxide was found to be the best titanium precursors. XRD analysis confirmed the anatase phase of TiC>2 . Activation of photocatalysts under visible light was confirmed by a reduction in band gap erergy as observed from UV-Vis DRS. The surface morphology of the photocatalyst samples was analysed by FESEM. The particles formed were in almost spherical shape with a specific surface area ranging from 17.54 to 23.65 m2/g for 0.75% N-F-TiC>2 (600) and 0.75% F-TiC>2 (600) respectively. Details of chemical and electronic states of elements were shown by XPS analysis. The N-C codoped TiC>2 photocatalyst was identified as an effective photocatalyst suitable for the photodegradation of organic pollutants