Hydrogen sensing properties of Pt-Au bimetallic nanoparticles loaded on ZnO nanorods

The mono-noble metal nanoparticles are often loaded onto the sensing materials to promote the gas sensing performance of the materils; however, there have been few reports concerning the effect of the multi-metallic nanoparticles on the sensing performance. It is reported that the multi-metallic nanoparticles shows different absorption and catalytic performance from their mono-metal analogues because of the geometric and electronic effect, so it is very necessary to investigate the gas sensing performance of the multi-metallic nanoparticles loaded materials. In this work, the Pt-Au alloying nanoparticles was prepared and supported on the ZnO nanorods, and this hybrid was used as the H-2 sensor for the first time. The sensing testing results indicate that the alloying nanoparticles loaded ZnO exhibits higher sensing response than the mono-metallic nanoparticles loaded ZnO. The Pt-Au bimetallic nanoparticles loaded ZnO shows high sensitivity to ppm-level of hydrogen even at room temperature, and the sensing response of (Pt-Au)-loaded ZnO to 250 ppm of H2 is 157, 47, and 9.6 times higher than that of pure ZnO, Pt-loaded ZnO, and Au-loaded ZnO, respectively. This superior performance of the (Pt-Au)-loaded ZnO to H2 is most probably due to the strong adsorption of H-2 onto the Pt-Au bimetallic nanoparticles caused by the geometric and electronic effects between the two metals. (C) 2016 Elsevier B.V. All rights reserved.