Synthesis-in-place of V2O5 nanobelts for wide range humidity detection

Resistive type humidity sensors offer advantages in simplicity, low cost, compact size, and remote operation. Due to the benefits, they have great potential for use in a variety of environments and future applications, including the Internet of Everything (IoE). However, resistive humidity sensors have limitations in detecting extreme humidity levels below 10 % or above 90 % relative humidity (RH) and are also vulnerable to high temperatures, which hinders their use in harsh environments applications. For broader applications, humidity sensors with reliable performance across the full range of humidity levels and high stability at elevated temperatures need to be developed. Here, we report high performance resistive humidity sensors based on V 2 O 5 nanobelts operating at high temperatures. The V 2 O 5 nanobelts are directly deposited between Pt electrodes by O 2 -assisted physical vapor transport (PVT) method. The V 2 O 5 nanobelt humidity sensor exhibits reliable humidity sensing properties over a wide range from 1 % to 100 % RH. Furthermore, long-term stability and reproducibility of V 2 O 5 nanobelts are demonstrated through 25 consecutive humid air pulses and measurements obtained after 4 months of storage. The high performance of the V 2 O 5 nanobelt humidity sensor is advantageous for practical use in applications ranging from IoE environments to harsh industrial conditions. • Synthesis-in-place V 2 O 5 nanobelts were fabricated by physical vapor transport method. • The V 2 O 5 nanobelt sensor shows high sensitivity to low humidity range from 1 % to 10 %. • The sensor demonstrates excellent long-term stability over 4 months. • The synthesis-in-place sensor exhibits high stability at elevated temperatures