Improving recovery performance of graphene oxide humidity sensors through pore modulation by intercalating TiO2 nanoparticles

A strategy is proposed to construct nano-porous channels inside graphene oxide (GO) layers through pore modulation by intercalating TiO2 nanoparticles of different amounts and sizes, which can significantly improve the recovery performance of GO humidity sensors. Typical device prepared by laser direct writing on the GO/TiO2 film shows a high sensitivity to a broad humidity range of 2 ∼ 85% and a significantly reduced recovery time of 40.5 s from 95.7 s for the one prepared on sole GO film. The intercalation of TiO2 nanoparticles constructs nano-porous channels effectively, which afford spaces to promote water molecule desorption and diffusion.