Enhanced UV activation of electrochemically doped Ni in ZnO nanorods for room temperature acetone sensing

We report the enhanced room temperature gas sensing properties of ZnO nanorods by promoting UV activation via doped Ni in ZnO. Electrodeposition was used to grow nickel-doped ZnO nanorods on flexible substrates integrated with 365 nm UV LED. Nickel concentration varied from 0 at.% to 10 at.% in aqueous solution. An enhanced gas sensing property up to 1.61 at room temperature was measured at 6 at.% Ni-doped ZnO, but showed deteriorated sensitivity due to the formation of a NiO phase at higher Ni concentration. The mechanism for improved sensing properties can be explained by the involvement of weakly bound photo-induced oxygen ions upon the exposure of acetone gas.