LAUSR

Abstract TiO2 nanosheet based flowerlike architectures with a surface area as high as 171 m2 g−1 were prepared through a solvothermal method. The sensing performance of TiO2 nanosheet based flowerlike architectures is enhanced by increasing density of surface unsaturated Ti atoms with dangling bonds through hydrogenation. We proposed a concept of the unsaturated Ti atoms serving as the sensing reaction active sites, and described in detail the sensing mechanism at the atomic and molecular level. The unsaturated Ti atoms not only generate non-contributing (free) electrons and adsorb oxygen molecules, but also catalyze the sensing reaction. In principle, the hydrogenation strategy may be used to improve sensing performances and catalytic activities of other metal oxides. The concept of the unsaturated metal Ti atoms serving as active sites can deepen understanding of the sensing and other catalytic reaction mechanisms, and provides a new insight to the design and fabrication of advanced sensing materials, catalysts and electronic devices.