Enhanced resistive acetone sensing by using hollow spherical composites prepared from MoO3 and In2O3
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Hollow sphere composites were synthesized by a template-free hydrothermal method from MoO3 and In2O3. The spheres have a typical size of 800 ± 50 nm and were characterized by XRD, FESEM, TEM, XPS. Gas sensors based on samples with different Mo/In composite ratios were fabricated and their gas sensing properties were studied. The results show that a Mo:In ratio of 1:1 in the composite gives the highest response, typically at a working temperature of 250 °C. The response increases to 38 when exposed to 100 ppm acetone at 250 °C. This is 13.6 times better than when using pure MoO3. The sensor shows improved selectivity, response, repeatability and long-term stability. Typical features include a large specific surface area, and high levels of chemisorbed oxygen and defective oxygen sites. The N-N heterojunction theory was used to explain the improvement of gas sensing performance.
KeywordsGas sensors Hydrothermal method Molybdenum oxide Indium oxide Hollow spheres Acetone Synergistic effect
This work is supported by National Key Research and Development Program of China (Nos. 2016YFC0201002 and 2016YFC0207300), the National Nature Science Foundation of China (Nos. 61831011, 61327804, 61520106003, 61803171 and 61833006), Program for Chang Jiang Scholars and Innovative Research Team in University (No. IRT13018), Application and Basic Research of Jilin Province (20130102010JC), Program for JLU Science and Technology Innovative Research Team (JLUSTIRT 2017TD-07), Fundamental Research Funds for the Central Universities.
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The author(s) declare that they have no competing interests.