Optimization of a nanoparticle ball milling process parameters using the response surface method

Abstract

Nanocrystalline TiO2-CeO2 powders were synthesized from their TiO2 and CeO2 oxides using mechanical ball milling process. The response surface method is applied to identify optimal parameters for the synthesis of TiO2-CeO2 photocatalyst. Analysis of variance and main effect plot are used to determine the significant parameters and set the optimal level for each parameter. Regression analysis showed good agreement of experimental data with the second-order polynomial model with a coefficients of determination: R-2 = 0.991, R-Adj(2). = 0.940 and R-Pred(2). = 0.983. Under optimal experimental conditions of TiO2:CeO2 weight percentage ratio 71: 29, milling speed 200 rpm, and milling time 115 min the highest photodegradation efficiency was achieved. On the basis of the above statistical analysis, it was found that the band gap energy of TiO2-CeO2 nanoparticles decreases with the increase of the milling speed and milling time with constant TiO2:CeO2 weight percentage ratio. Obtained results suggest that mechanical ball milling process is a rapid, efficient and low energy consumption method to synthesize TiO2-CeO2 photocatalyst.