Hydrogen sensing kinetics of laterally aligned MoO3 nanoribbon arrays with accelerated response and recovery performances at room temperature

Fast, Sensitive, and Highly Selective Room-Temperature Hydrogen Sensing of Defect-Rich Orthorhombic Nb2O5–x Nanobelts with an Abnormal p-Type Sensor Response

“…After the initial surface reaction stage, the diffusion process under the concentration gradient induced by the consumption of the surface reactant (response process) and the readsorption of surface states (recovery process) will become the predominant factors that affect the sensor response kinetics. As reported previously, the diffusion of adsorbed oxygens might be suppressed by the “nanojunctions” between the adjacent nanobelts in the sensing layer. , To investigate the nanojunction effect on the interface diffusion process, the sensor kinetics within the full recovery process were studied. A dynamic model with the surface coverage of adsorbed oxygens (θ) closely related to an effectiveness factor (η) was employed, where the η factor represents the ratio of the observed surface kinetics rate to the ideal surface kinetics by neglecting the interface diffusion of oxygen .…”

“…As reported previously, the diffusion of adsorbed oxygens might be suppressed by the "nanojunctions" between the adjacent nanobelts in the sensing layer. 45,46 To investigate the nanojunction effect on the interface diffusion process, the sensor kinetics within the full recovery process were studied. A dynamic model with the surface coverage of adsorbed oxygens (θ) closely related to an effectiveness factor (η) was employed, where the η factor represents the ratio of the observed surface kinetics rate to the ideal surface kinetics by neglecting the interface diffusion of oxygen.…”

Room-Temperature Semiconductor Gas Sensors: Challenges and Opportunities

“…RT operable H 2 sensors are particularly attractive owing to their intrinsic safety. The self-assembly of 1D MoO 3 into flexible thin films has been utilized to explore the H 2 -sensing effect at RT. , Gu et al constructed an RT H 2 sensor based on MoO 3 nanowire paper. Its massive porous structure and high specific surface favored the absorption of oxygen molecules, therefore simultaneously improving the utility factor and receptor function.…”

“…The adverse effect of interfacial diffusion of adsorbed surface states on the overall response and recovery process were effectively suppressed, significantly accelerating the recovery speed. The recovery time of the sensor for 100 ppm hydrogen at RT was shortened to 16 s …”

Advances in the designs and mechanisms of MoO3 nanostructures for gas sensors: a holistic review

“…Moreover, the gas sensors made of these 1-D nanostructures offer ultra-sensitivity, fast response, higher stability, low-temperature operations, and less power consumptions 101,102 . Till date, variety of 1-D nanostructures including nanobelts 60,72,73,96,99,[101][102][103][104][105] , nanoribbons 56,59,100,106,107 , nanorods 74,75,97,[108][109][110][111][112][113] , nanofibers 76,114 , nanowires 82 and microrods 98,115,116 of MoO3 have been utilized in gas sensors and the following section summarize about these nanostructures with their gas sensing performance and mechanism. An overview of gas sensors based on 1-D MoO3 nanostructures is listed in Table 1.…”