Improved performance of fiber optic hydrogen sensor based on MoO3 by ion intercalation

α-MoO3 has been widely investigated as hydrogen sensing material due to its excellent electrical and optical properties. However, its irreversible structure change during reaction with hydrogen results in an obvious degradation of the sensor's performance. In this paper, an ion intercalated method is proposed to improve the stability of fiber bragg grating (FBG) hydrogen sensor based on MoO3. Na+ and K+ ions are successfully intercalated into MoO3 nanobelts and the effect of the intercalated ions' amount to sensing performance has been investigated. Compared to MoO3, ion intercalated MoO3 nanobelts exhibits significant improvement in stability and cycling performance. XRD and TEM analysis reveal that intercalated ions between the interlayers can reinforce the layer structure and inhibit the phase transition. This ion intercalation strategy may provide a new perspective to improve stability of sensors based on layer molybdenum trioxide and dichalcogenides.