Noble metal (Pd,Pt) doped ZnO: A promising complementary array for DGA in transformer oil based on DFT method

Abstract

In this study, we utilized a metal oxide sensor array for the quantitative detection of three characteristic dissolved gases (C2H2, CO, and C2H4) in transformer oil. Our focus was directed towards investigating noble metal doped ZnO materials through density-functional theory (DFT) simulations to verify the capabilities of the sensor array. Physical structures and adsorption parameters of the pure ZnO, Pd-ZnO, and Pt-ZnO toward the three gases were calculated and analyzed. Through an analysis of the density of states and charge density difference (CDD), our investigation revealed that Pd doping significantly enhances the adsorption energy and charge transfer amplitude by approximately 10 and 3 times, respectively, compared to pure ZnO for C2H2. Furthermore, to verify the array’s detection of the other characteristic gases, we calculated and analyzed the adsorption energy and partial density of states (PDOS) curves of the three gas-sensitive materials, respectively, and results indicated their complementary sensitivities to the three characteristic gases. The complementary responses of the noble metal doped ZnO materials provide a new method of fabricating the gas sensor array, and then quantitatively detecting concentrations of the characteristic gases in transformer dissolved gas analysis (DGA) through artificial intelligent algorithm based on the sensor array.