[1] Zhang K, Liu S L, Liu M M et al. Research developments of hydrogen energy[J]. Materials Review, 25, 116-119(2011).

[2] Yan Q, Chen Y C, Wang A J et al. Development obstacles of new energies in China and countermeasures: a review on global current situation[J]. Acta Geoscientica Sinica, 31, 759-767(2010).

[3] Lu J, Zahedi A, Yang C S et al. Building the hydrogen economy in China: drivers, resources and technologies[J]. Renewable and Sustainable Energy Reviews, 23, 543-556(2013).

[4] Butler M A. Fiber optic sensor for hydrogen concentrations near the explosive limit[J]. Journal of the Electrochemical Society, 138, L46-L47(1991).

[5] Lin D J, Jiang X Q, Xie F et al. High stability multiplexed fiber interferometer and its application on absolute displacement measurement and on-line surface metrology[J]. Optics Express, 12, 5729-5734(2004).

[6] Javahiraly N. Review on hydrogen leak detection: comparison between fiber optic sensors based on different designs with palladium[J]. Optical Engineering, 54, 030901(2015).

[7] Mu K, Tong X L, Hu P et al. Technology status and development trend of hydrogen sensor[J]. Laser Journal, 37, 1-5(2016).

[8] Jing Y P. Research progress of gas sensor[J]. Silicon Valley, 6, 11-13(2013).

[9] Tian H L, Fan H Q, Li M M et al. Zeolitic imidazolate framework coated ZnO nanorods as molecular sieving to improve selectivity of formaldehyde gas sensor[J]. ACS Sensors, 1, 243-250(2016).

[10] Tian H L, Fan H Q, Ma J W et al. Pt-decorated zinc oxide nanorod arrays with graphitic carbon nitride nanosheets for highly efficient dual-functional gas sensing[J]. Journal of Hazardous Materials, 341, 102-111(2018).

[11] Zheng X K, Fan H Q, Wang H et al. ZnO-SnO2 nano-heterostructures with high-energy facets for high selective and sensitive chlorine gas sensor[J]. Ceramics International, 46, 27499-27507(2020).

[12] Ma J W, Fan H Q, Li Z X et al. Multi-walled carbon nanotubes/polyaniline on the ethylenediamine modified polyethylene terephthalate fibers for a flexible room temperature ammonia gas sensor with high responses[J]. Sensors and Actuators B: Chemical, 334, 129677-129683(2021).

[13] Xin X, Wu Y W, Liu H M et al. A new fabrication method of fiber Bragg grating hydrogen sensor[J]. Acta Optica Sinica, 41, 0406002(2021).

[14] Shim J Y, Lee J D, Jin J M et al. Pd-Pt alloy as a catalyst in gasochromic thin films for hydrogen sensors[J]. Solar Energy Materials and Solar Cells, 93, 2133-2137(2009).

[15] Yang M H, Liu H L, Zhang D S et al. Hydrogen sensing performance comparison of Pd layer and Pd/WO3 composite thin film coated on side-polished single- and multimode fibers[J]. Sensors and Actuators B: Chemical, 149, 161-164(2010).

[16] Yang M H, Dai J X, Min W et al. Thin film-based optical fiber sensors[C](2010).

[17] Yang M H, Sun Y, Zhang D S et al. Using Pd/WO3 composite thin films as sensing materials for optical fiber hydrogen sensors[J]. Sensors and Actuators B: Chemical, 143, 750-753(2010).

[18] Matsuyama N, Okazaki S, Nakagawa H et al. Response kinetics of a fiber-optic gas sensor using Pt/WO3 thin film to hydrogen[J]. Thin Solid Films, 517, 4650-4653(2009).

[19] Wittwer V, Datz M, Ell J et al. Gasochromic windows[J]. Solar Energy Materials and Solar Cells, 84, 305-314(2004).

[20] Lee S H, Cheong H M, Zhang J G et al. Electrochromic mechanism in a-WO3-y thin films[J]. Applied Physics Letters, 74, 242-244(1999).

[21] Luo J Y, Deng S Z, Tao Y T et al. Evidence of localized water molecules and their role in the gasochromic effect of WO3 nanowire films[J]. The Journal of Physical Chemistry C, 113, 15877-15881(2009).

[22] Zhou W. Study on the preparation and properties sensitive to hydrogen of tungsten oxide films[D], 19-24(2007).

[23] Xu J. Study on preparation and property of tungsten oxide films[D], 21-22(2005).

[24] Xu Y. Study on the property and mechanism sensitive to hydrogen of tungsten oxide films doped catalyst[D], 11-14(2006).

[25] Zhang L L. The reflective optical fiber hydrogen sensor and its hydrogen sensitivity testing[D], 6-7(2012).

[26] Fan X H. Preparation of optical WO3-based hydrogen-sensing thin film and its properties[D], 8-12(2007).