Humidity sensing properties of novel graphene/TiO2 composites by sol-gel process

This study prepared a novel sensing graphene/TiO2 (G/TiO2) material by using a sol-gel method with 1 wt%, 5 wt%, 10 wt%, and 20 wt% of graphene. The structure and morphology of the materials were characterized using X-ray diffraction, Fourier transform infrared spectrometry, Transmission electron microscopy, and N2 adsorption-desorption technology. The humidity-sensing properties were measured using an inductance-capacitance-resistance analyser. At a relative humidity of 12-90%, the sample with 10% of graphene exhibited more favourable humidity-sensing properties compared with the other samples. The prepared sensor exhibited a higher sensing response (S = 151) and larger Brunauer-Emmett-Teller surface area (169.5 m2/g) than sensors reported in previous studies. Moreover, the humidity hysteresis value (<0.39%) was very small at all tested humidity conditions. Our results demonstrate the potential for applying G/TiO2 composite materials to the fabrication of high-performance humidity sensors.