Citrate-assisted one-pot assembly of palladium nanoparticles onto ZnO nanorods for CO sensing application

A facile one-pot strategy was developed for functionalization of palladium nanoparticles (Pd NPs) onto single crystalline ZnO nanorods (NRs). ZnO NRs (150–200 nm in length and 20–25 nm diameters) were synthesized by the solvothermal method, whereas the Pd NPs (below 5 nm) were deposited on the surface of ZnO NRs by the solution growth method. Sensor fabricated by the Pd/ZnO NRs showed significantly enhanced sensing performance as compared to pristine ZnO NRs. The increase in response of ZnO NRs after Pd NPs loading was attributed to electronic as well as chemical sensitization of Pd NPs.