Humidity
sensors with good repeatability, low hysteresis, and low-power
consumption are increasingly important for environmental monitoring
and industrial control applications. Herein, an impedance-type humidity
sensor under low working voltage (5 mV) utilizing a rGO-BiVO4 nanocomposite is demonstrated. The rGO-BiVO4 humidity
sensor exhibits superior sensing performances, including good repeatability,
negligible hysteresis (0.47%), fast response and recovery time, low
power consumption, good stability, and anti-interference ability.
The ultraviolet–visible absorption spectrum reveals that the
narrow band gap of the rGO-BiVO4 nanocomposite is conductive
to the electron transfer. The complex impedance spectra and the energy
band structure analysis further suggest that the boosted humidity
performance results from the formation of a heterojunction and the
decrease of the heterojunction barrier height. The facile fabrication
route, enhanced sensing performance, and excellent device reliability
make the rGO-BiVO4 sensor highly attractive for high-end
humidity sensing applications.