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 TiO 2 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/TiO 2 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 TiO 2 nanoparticles constructs nano-porous channels effectively, which afford spaces to promote water molecule desorption and diffusion.