Porous Pb-Doped ZnO Nanobelts with Enriched Oxygen Vacancies: Preparation and Their Chemiresistive Sensing Performance

Abstract

Among various approaches to improve the sensing performance of metal oxide, the metal-doped method is perceived as effective, and has received great attention and is widely investigated. However, it is still a challenge to construct heterogeneous metal-doped metal oxide with an excellent sensing performance. In the present study, porous Pb-doped ZnO nanobelts were prepared by a simply partial cation exchange method, followed by in situ thermal oxidation. Detailed characterization confirmed that Pb was uniformly distributed on porous nanobelts. Additionally, it occupied the Zn situation, not forming its oxides. The gas-sensing measurements revealed that 0.61 at% Pb-doped ZnO porous nanobelts exhibited a selectively enhanced response with long-term stability toward n-butanol among the investigated VOCs. The relative response to 50 ppm of n-butanol was up to 47.7 at the working temperature of 300 °C. Additionally, the response time was short (about 5 s). These results were mainly ascribed to the porous nanostructure, two-dimensional belt-like morphology, enriched oxygen vacancies and the specific synergistic effect from the Pb dopant. Finally, a possible sensing mechanism of porous Pb-doped ZnO nanobelts is proposed and discussed.

Keywords

• zinc oxide
• lead doping
• partial cation exchange reaction
• n-butanol
• gas sensing