Exploring 2D hexagonal WO3/COK-12 nanostructures for efficient humidity detection

Abstract

This research reports a pioneering approach to humidity sensing by leveraging the unique properties of 2D hexagonal mesoporous COK-12 (Centrum voor Oppervlaktechemie & Katalyse-12/Center for Surface Chemistry & Catalysis – 12). In this research, the utilization of these innovative COK-12 structures showcases their potential for advancing humidity-sensing technology, marking a significant stride in the field of surface chemistry and catalysis. We investigated how electrical resistance changes in (x-WO₃)/COK-12 (with x = 0%, 1%, 3%, 6%, and 9%) with varying humidity levels. The samples containing diverse tungsten concentrations in COK-12 were synthesized by a hydrothermal method and characterized using appropriate tools. The results demonstrate the successful integration of tungsten ions into COK-12, maintaining its distinctive hexagonal mesoporous structure and high specific surface area (864 m² g⁻¹). Tungsten-doped COK-12 humidity sensors exhibit great sensitivity and response speed due to modified conductivity under humid conditions, enhancing moisture measurement precision. Notably, the 6%-WO₃/COK-12 sensor exhibits a linear correlation between relative humidity and electrical resistance, signifying strong sensitivity. The sensor displays a significant 4.3 orders of magnitude resistance shift, with rapid 12 s response and 11 s recovery times. These findings enhance our understanding of COK-12's humidity sensing capabilities, opening avenues for diverse applications like environmental monitoring, weather forecasting, and industrial processes including catalysis, adsorption, and drug delivery.