Promoting the humidity sensing capabilities of titania nanorods/rGO nanocomposite via de-bundling and maximizing porosity and surface area through lyophilization

Abstract

Herein, the preparation of titania nanorods with reduced graphene oxide nanocomposite is introduced using a combination of the simple hydrothermal process and co-precipitation followed by freeze-drying. The preceding nanocomposite is functioned as a humidity sensor to detect the surrounding moisture levels. The XRD results reveal the confirmed incorporation of titania nanotubes onto the reduced graphene oxide sheets. The STEM and HRTEM consequences support the XRD structural results. Raman and FTIR bands reveal the disappearing significance of D and G bands for reduced graphene oxide. BET assessment study demonstrates the resultant maximized pores size accompanied by raised overall exposed surface area. The humidity sensing measurements within a broad spectrum of surrounding humidity (11%–97%) disclose a decent response and recovery times of 40 s and 166 s consecutively. Successful exposure to freeze-drying promotes the stabilized and enlarged surface area accompanied by the hindering of the realized hydrophobicity of the titania which opposes the humidity sensing application. The simple route of humidity sensing for this nanocomposite delivers a superior message to the humidity sensing applications over a wide range of areas. • Freeze-drying could deliver highly stable, porous, and suitable composites recommended for humidity sensing applications • The pores' size and the surface area of the resultant titania nanorods/ reduced graphene oxide (TNR/rGO) nanocomposite were maximized throughout the lyophilization process also the humidity sensing performance enhanced.