Titanium Dioxide/Graphene Oxide Nanocomposite-Based Humidity Sensors with Improved Performance

Abstract

Accurate relative humidity (RH) measurement is critical in many applications, from process control and material preservation to ensuring human comfort and well-being. This study presents high-performance humidity sensors based on titanium oxide nanoparticles/graphene oxide (TiO<inf>2</inf>/GO) composites, which demonstrate excellent sensing capabilities compared to pure GO-based sensors. The multilayer structure of the TiO<inf>2</inf>/GO composites enables the enhanced adsorption of water molecules and improved dynamic properties while providing dual-mode sensing capability through both resistive and capacitive measurements. Sensors with different TiO<inf>2</inf>/GO ratios were systematically investigated to optimize performance over different humidity ranges. The TiO<inf>2</inf>/GO sensor achieved remarkable sensitivity (8.66 × 10⁴ Ω/%RH), a fast response time (0.61 s), and fast recovery (0.87 s) with minimal hysteresis (4.09%). In particular, the sensors demonstrated excellent mechanical stability, maintaining reliable performance under bending conditions, together with excellent cyclic stability and long-term durability. Temperature dependence studies showed consistent performance under controlled temperature conditions, with the potential for temperature-compensated measurements. These results highlight TiO<inf>2</inf>/GO nanocomposites as promising candidates for next-generation humidity sensing applications, offering enhanced sensitivity, mechanical flexibility, and operational stability. The dual-mode sensing capability combined with mechanical durability opens up new possibilities for flexible and wearable humidity-sensing devices.