factors affecting photocatalytic degradation of reactive green-19 with cdo-tio_2 nanocomposite

Cdo-tio_2 nanocomposites were synthesized by varying the molar ratio of cdo: tio_2 as 1:1, 1:2, and 2:1 using the sol-gel method. the ph value for all the cdo-tio_2 nanocomposites was controlled at two different values, ph-3 and ph-13. the nanocomposites were used for facilitating photolytic degradation of azo dye (reactive green-19). the surface morphology, crystallinity, and properties related to interactions with the light of the prepared catalyst were examined by scanning electron microscopy (fe-sem), x-ray diffraction (xrd), and ultraviolet-visible (uv-vis) spectrophotometer, respectively. the nanocomposites for all molar ratios synthesized at ph-3 showed rod-like structure and some irregular shapes, while those synthesized at ph-13 were spherical. from xrd patterns, composites at ph-3 and ph-13 were crystalline; however, those at ph-3 were more crystalline. the parameters, namely initial dye concentration, ph of dye solution, and catalyst concentration, affecting photocatalytic activities were examined and optimized at 75 ppm, ph-7.5, and 1g/l, respectively. the progress of the degradation process of reactive green-19 was observed by monitoring the change in the concentration of the dye after a certain time interval by measuring the absorbance by uv-vis spectrophotometer. catalyst a1:1 (the nanocomposites obtained at ph-3 with 1:1 mol% of cdo:tio_2) showed maximum degradation (94.53 %) at a catalyst concentration of 1 g/l.