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

The fast and accurate hydrogen detection is of great significance to the development of hydrogen energy and related techniques. In this work, a simple and cost-effective dielec-trophoresis method was employed for fabricating well-aligned lateral arrays of [001]-oriented orthorhombic MoO3 nanoribbons, which exhibit remarkably accelerated room-temperature sensing performance towards 100 ppm of hydrogen with response and recovery time down to 3 s and 16 s. The study on the hydrogen sensing kinetics suggested that the nanoribbon arrays exhibited much higher initial response rate of 2.067%/s than the randomly arranged samples. Moreover, the contribution from the interface diffusion of the adsorbed surface states to the overall response and recovery process could be effectively suppressed by the well-alignment of the nanoribbons. The results also suggested that the suppression of such nanojunction effect will be more effective for building semiconductor sensors towards hydrogen gas with relatively lower concentrations. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.