Enhanced No2 Sensing Property Of Zno By Ga Doping And H-2 Activation

Ga-doped ZnO nanoparticles are successfully prepared by a facile coprecipitation method and then are activated by H-2 annealing. The as-prepared ZnO powders are characterized by X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, Raman and photoluminescence spectroscopies. Gas sensing property using NO2 as probe shows that the 1at.% Ga-ZnO powders activated in H-2 at 540 degrees C showed high NO2 response of approximate to 50/ppm, high selectivity toward typical interferences such as ethanol, acetone, toluene, NO, SO2, C2H6, and C2H4 and high stability as measured at 200 degrees C. On the contrary, the pure ZnO and the Ga-ZnO without H-2 activation show far lower response, which illustrates the effect of Ga dopant activation by H-2 annealing aimed for the high performance gas sensing materials.