Research status of H2 gas sensors based on nano WO3 semiconductor materials

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Research status of H2 gas sensors based on nano WO3 semiconductor materials

Journal Title: China Powder Science and Technology - Year 2024, Vol 30, Issue 5

Abstract

Progress　WO3 materials are known for their flexible structural properties， which can improve gas sensing performance through various approaches， such as noble metal catalysis and heterostructure construction. Doping WO3 with noble metals such as palladium and platinum and constructing heterojunctions with other semiconductors are strategies that have been proved to significantly enhance hydrogen selectivity and sensitivity. This paper reviews the current research and future prospects of hydrogen sensors， focusing on four areas： preparation methods， morphological characteristics， gas-sensing performance， and mechanisms. Sensor materials are prepared using methods such as hydrothermal synthesis， sol-gel processes， radio frequency magnetron sputtering （RFMS）， and glancing angle deposition （GLAD）. These materials are then characterized using scanning electron microscopy （SEM）， transmission electron microscopy （TEM）， and X-ray diffraction （XRD）， and their gas-sensitive properties are evaluated using various instruments. Consequently， the underlying mechanisms are explained scientifically and precisely. Conclusion and Prospects　WO3 is one of the most promising materials in the field of sensing technology and has become a focal point of research in recent years. This paper reviews the preparation methods of WO3 nanomaterials and their composites， as well as the current research advancements in H2 gas detection. The morphology of metal oxides has a significant impact on gas-sensing performance. The specific surface areas and exposed crystal surfaces of WO3 vary with different morphologies， resulting in differences in contact areas and active sites for target gases. Thus， the preparation of WO3 materials with distinct morphologies has become a crucial area of research. One of the most common methods for improving gas-sensing performance is the introduction of noble metal doping. This can be achieved through chemical and electronic sensitization， which enhances sensor response. The strong coupling effect between specific metals and certain gases also improves sensor selectivity and reduces operating temperature. The dissociation of hydrogen atoms by platinum at room temperature greatly reduces the operating temperature of the sensor. Also， doping palladium into tungsten trioxide， a semiconductor， significantly enhances hydrogen detection. Studies have demonstrated that compared to pure WO3， palladium doping significantly improves hydrogen detection. Overall， the doping of noble metals and the construction of heterojunctions can reduce operating temperature， enhance sensitivity， reduce the detection limit， and shorten the recovery and response times， making these strategies highly effective compared to using only pure phase WO3 semiconductor materials. Significance As an n-type semiconductor， WO3 is widely used in the field of gas sensors due to its wide band gap， high thermal stability， and easy synthesis. Given the importance of monitoring hydrogen concentration in ensuring the safety of industrial production and daily life， it is crucial to develop gas sensors that achieve both rapid response and high sensitivity to hydrogen.

Authors and Affiliations

Hongyan XU, Gen LI

Keywords

gas sensor oxide semiconductor tungsten trioxide

EP ID EP749289
DOI 10.13732/j.issn.1008-5548.2024.05.002
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