Strongly coupled Ag/TiO2 heterojunction: from one-step facile synthesis to effective and stable ethanol sensing performances.

The development of cost-effective simple methods to fabricate nanocomposites based on metal oxide (MOX) supported noble metals with improved performance is extremely demanding, specifically in the field of nanomaterial and gas sensor. In this this work, a facile one-step hydrothermal strategy to synthesize strongly-coupled TiO₂ nanosheets supported with Ag nanoparticles (Ag/TiO₂ heterojunction nanocomposites) is proposed, which is proved of high effectiveness for sensor applications. The structure and morphology of synthesized nanocomposites was performed by XRD, XPS, HRTEM, UV-Vis and PL spectroscopy. Compared to pristine TiO₂, the sensors based on such Ag/TiO₂ heterojunction nanocomposites show excellent ethanol gas sensing properties in terms of high sensitivity (8.5 towards 100 ppm), selectivity against other gases (methanal, acetone, and methanol), short response/recover times (9/10 s), and high stability (present stable response after 30 days). Such performance demonstrates this material is promising for practical gas sensor applications. [ABSTRACT FROM AUTHOR]