Investigation on synthesis and excellent gas-sensing properties of hierarchical Au-loaded SnO 2 nanoflowers
- PDF / 1,848,336 Bytes
- 11 Pages / 584.957 x 782.986 pts Page_size
- 70 Downloads / 227 Views
FOCUS ISSUE
BUILDING HIERARCHICAL MATERIALS VIA PARTICLE AGGREGATION
Investigation on synthesis and excellent gas-sensing properties of hierarchical Au-loaded SnO2 nanoflowers Yanlei Cui1, Ming Zhang1,a), Xuewei Li1, Bingrong Wang1, Ruzhi Wang1 1
The Key Laboratory of Advanced Functional Materials, Ministry of Education of China, Beijing University of Technology, Beijing 100124, People’s Republic of China; and College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, People’s Republic of China a) Address all correspondence to this author. e-mail: [email protected] Received: 29 May 2019; accepted: 31 July 2019
The hierarchical Au-loaded SnO2 nanoflowers were synthesized using a new developed self-reductive hydrothermal method, of which the gas-sensing properties were enhanced significantly. The SnO2 hierarchical nanoflowers were composed of well-defined nanosheets with a specific surface area of around 84 m2/g. Gas sensors made of pure and Au-doped SnO2 were fabricated, and their gas-sensing properties were characterized. The 1.0 at.% Au-loaded SnO2 sensor prepared by the new developed self-reductive method showed much more excellent selectivity toward ethanol at 200 °C than the one prepared with the conventional hydrothermal method. Its response to ethanol was around 3 times higher than that of the pure SnO2 sensor. A very wide detection range of 1–500 ppm for ethanol, good repeatability, and long-term stability were also approved.
Introduction Gas sensors play an important role in environmental monitoring, chemical process control, and personnel safety. Metal oxide–based semiconductors (MOSs), such as ZnO, NiO, WO3, and In2O3, have been regarded as promising candidates for gas sensors and investigated intensively because of their fascinating physicochemical properties, i.e., high selectivity and sensitivities to target gases, and simplicity in synthesis for the past ten years [1, 2, 3, 4, 5, 6, 7, 8, 9]. It was reported that gas sensing was mainly based on the chemical interaction of gas molecules with the surface atoms of oxides, leading to change in electrical conductivity [10, 11, 12, 13]. Thus, the performances of gas sensors are influenced significantly by compositions, particle size, and morphology of microstructures [10, 11, 12, 13]. It is confirmed that the special structure and novel morphology are the key issues to exhibit enhanced properties for promising gas-sensing performances [2, 14, 15]. Unfortunately, low-dimensional structures such as nanoparticles tend to aggregate, resulting in a decrease in the specific surface area, surface reactivity, and then the gas-sensing performance and stability of gas sensors [16, 17, 18]. By contrast, threedimensional (3D) porous structures are able to maintain and even enhance the gas-sensing stability and sensitivity for a long time at relatively high working temperatures. Recently, metal
ª Materials Research Society 2019
oxide semiconductors with hierarchical structures that exhibit higher dimensional microstructures or nanostru
Data Loading...
