Research News
Nano-sensors Modificated to Improve Gas-Sensing
Date: 2017/02/13 Author: LI Yixiang; GUO Zheng

Nano-sensors could be refined to realize high sensitivity and high stability of gas-sensing performance, reported a study team led by Prof. HUANG Xingjiu and Prof. LIU Jinhuai at Institute of Intelligent Machines, Hefei Institutes of Physical Science in journal of Nanotechnology and ACS Sensors.

As for sensors fabrication, nanomaterials with porous structures have sparked scientists' curiosity for the last several decades about their fascinating abilities, say, the higher active surface-to-volume ratios in contrast to solid nanomaterials, greatly enhancing their response; and the porous nanostructures that are more favorable for the diffusion of detected gases, suggesting that their response and recovery time can be expectedly improved.

Herein, based on the sensitive materials of ZnO, the team combined method of precursor calcinating and technology of L-B film self-assembly technology to design porous and single crystalline nanobelts.

Because of the synergistic effect from their porous and single-crystalline nanostructures, the new-designed sensors presents better sensing performance with high response and repeatability toward volatile organic compounds (VOCs). Promisingly, the porous ZnO nanobelts with a single-crystalline structure could be expected as novel sensing materials to fabricate ng electronic nanodevices.

Additionally, researchers also design the synthesis of three-dimensional hierarchical SnO2 nanostructures. Via controlling the evolution of their hierarchical nanostructures, they find that the sensing behaviors are greatly related with their hierarchical morphologies.

The result analysis indicates that their good sensing performance is mainly attributed to the formation of more active surface defects and mismatches during the process of thermal recrystallization.

Among the achieved hierarchical morphologies, three-dimensional cone-shaped hierarchical SnO2 nanostructures display the highest relative response up to about 175 toward 100 ppm of acetone as an example. Furthermore, they also exhibit good sensing responses toward other typical VOCs. Evidently, it exhibits good stability and the response rate only declines about 15% after four months.

Most importantly, the above-mentioned works can be potentially extended to fabricate electronic nanodevices and other three-dimensional metal oxide hierarchical nanostructures with good gas-sensing and catalytic performance.

These two works were supported by the National Key Scientific Program-Nanoscience and Nanotechnology, the National Natural Science Foundation of China.

Link to the thesis 1:Porous and single-crystalline ZnO nanobelts: fabrication with annealing precursor nanobelts, and gas-sensing and optoelectronic performance

Link to the thesis 2: Hierarchical Morphology-Dependent Gas-Sensing Performances of Three-Dimensional SnO2 Nanostructures


The diagram of porous and single-crystalline ZnO nanobelts gas-sensing sensors fabrication and structure characterization (top left). Labtalk News reports (right). The evolution of three-dimensional hierarchical SnO2 nanostructures and its gas-sensing performances (lower left).

(Imaged by GUO Zheng)



HUANG Xingjiu

Institute of Intelligent Machines (http://english.iim.cas.cn/)

Hefei, Anhui, P. R. China 

Tel: 86-551-65591167

Email: xingjiuhuang@iim.ac.cn

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