AUTHOR=Yu Aihua , Xun Haitao , Yi Jianxin 

TITLE=Improving Hydrogen Sensing Performance of TiO2 Nanotube Arrays by ZnO Modification

JOURNAL=Frontiers in Materials

VOLUME=6

YEAR=2019

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2019.00070

DOI=10.3389/fmats.2019.00070

ISSN=2296-8016

ABSTRACT=<p>In this work, anodization was utilized to synthesize highly ordered TiO<sub>2</sub> nanotube arrays, and ZnO was successfully decorated onto the surface of as-prepared TiO<sub>2</sub> nanotubes <italic>via</italic> a facile impregnation method. The gas sensing performance of a TiO<sub>2</sub>@ZnO composite was systematically studied. At a working temperature of 300°C, the response of TiO<sub>2</sub>@ZnO to 100 ppm H<sub>2</sub> was ~340, 2.7 times larger than that of pristine TiO<sub>2</sub>. A power–law relationship between the response and H<sub>2</sub> concentration was observed. In addition, the response time was significantly reduced by four times, and improved selectivity to H<sub>2</sub> was achieved. The highly improved sensing performance of TiO<sub>2</sub> nanotubes by ZnO decoration may be attributed to the enhanced oxygen adsorption and formation of n-n heterojunctions.</p>