Process optimization for electrochemical synthesis of ZnO nanoparticles with respect to productivity and consumption using TOPSIS and Taguchi methods.

Electrochemical synthesis method for fabrication of ZnO nanoparticles is widely used due to its simplicity, low temperature operation, low energy consumption and greater purity of the synthesized product. This paper proposed a process optimization method, namely, TOPSIS-Taguchi method, for electrochemical synthesis of ZnO nanoparticles with respect to productivity and consumption using TOPSIS and Taguchi methods. TOPSIS is used to convert multiple responses into a single integrated response (IR), and Taguchi method is used to design experiment and find optimal process parameters (PPs) to optimize the multiple responses. We determined the optimal PPs pH, concentration (CC), voltage (VL), and conductivity (CD) to maximize the productivity of ZnO nanoparticles and minimize the specific energy consumption and specific electrode consumption. The optimal PPs were pH of 5, CC of 0.05 M, VL of 8 V, and CD of 30ms/cm, and their effect ranking on the IR was CC (37.657%), CD (32.498%), pH (15.614%), and VL (14.231%). Moreover, we developed the multiple quadratic regression model that reflects the relationship between the IR and the PPs, and determined the optimal PPs using grid search optimization method. The result was perfectly the same to the proposed TOPSIS-Taguchi method. The proposed method could be widely used to not only electrochemical synthesis process optimization of ZnO nanoparticles but also various materials fabrication process optimization problems.