| Title: | Ultrasensitive Detection of Volatile Organic Compounds by a Pore Tuning Approach Using Anisotropically Shaped SnO(2) Nanocrystals |
| Author(s): | Kida T; Suematsu K; Hara K; Kanie K; Muramatsu A; |
| Address: | "Division of Materials Science, Faculty of Advanced Science and Technology, Kumamoto University , Kumamoto 860-8555, Japan. Chemical and Textile Research Institute , Fukuoka Industrial Technology Center, Fukuoka 818-8540, Japan. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University , Sendai, Miyagi 980-8577, Japan" |
| Journal Title: | ACS Appl Mater Interfaces |
| ISSN/ISBN: | 1944-8252 (Electronic) 1944-8244 (Linking) |
| Abstract: | "Gas sensing with oxide nanostructures is increasingly important to detect gaseous compounds for safety monitoring, process controls, and medical diagnostics. For such applications, sensor sensitivity is one major criterion. In this study, to sensitively detect volatile organic compounds (VOCs) at very low concentrations, we fabricated porous films using SnO(2) nanocubes (13 nm) and nanorods with different rod lengths (50-500 nm) that were synthesized by a hydrothermal method. The sensor response to H(2) increased with decreasing crystal size; the film made of the smallest nanocubes showed the best sensitivity, which suggested that the H(2) sensing is controlled by crystal size. In contrast, the responses to ethanol and acetone increased with increasing crystal size and resultant pore size; the highest sensitivity was observed for a porous film using the longest nanorods. Using the Knudsen diffusion-surface reaction equation, the gas sensor responses to ethanol and acetone were simulated and compared with experimental data. The simulation results proved that the detection of ethanol and acetone was controlled by pore size. Finally, we achieved ultrahigh sensitivity to ethanol; the sensor response (S) exceeded S = 100?ª+000, which corresponds to an electrical resistance change of 5 orders of magnitude in response to 100 ppm of ethanol at 250 degrees C. The present approach based on pore size control provides a basis for designing highly sensitive films to meet the criterion for practical sensors that can detect a wide variety of VOCs at ppb concentrations" |
| Keywords: | Knudsen diffusion SnO2 gas sensor nanocubes nanorods pore control; |
| Notes: | "PubMed-not-MEDLINEKida, Tetsuya Suematsu, Koichi Hara, Kazuyoshi Kanie, Kiyoshi Muramatsu, Atsushi eng 2016/12/17 ACS Appl Mater Interfaces. 2016 Dec 28; 8(51):35485-35495. doi: 10.1021/acsami.6b13006. Epub 2016 Dec 16" |
