Increasing sensitivity of ZnO nanoparticles by hydrogenation and sensing reaction mechanism

Sensing reaction mechanism is decisive for improvement of the sensing property of metal oxide sensing materials. Herein, we demonstrated a conceptually different approach to improving sensing property of ZnO nanoparticles by increasing quantity of the surface unsaturated 3-coordinated Zn atoms through hydrogenation. The surface 3-coordinated Zn atoms play a pivotal role in sensing reaction. They can produce electrons, adsorb O 2 and catalyze the gas sensing reaction between the adsorbed oxygen and test gas. A sensing mechanism of the unsaturated Zn atom serving as a sensing reactive site is presented for the first time. The mechanism provides a deep understanding for sensing and catalytic reaction mechanisms. In addition, the sensing performance of other sensing materials and reactive activity of catalysts may be enhanced by increasing concentration of surface unsaturated metal atom through hydrogenation.