Novel highly flexible room temperature humidity sensor based on mesoporous NiO/TUD-1 hybrid nanocomposite

This work presents a pioneering investigation into humidity sensing, focusing on TUD-1, a mesoporous material developed at Technical University of Delft. TUD-1 has a 3-D sponge-like structure that can be synthesized through a versatile and straightforward pathway without the need of surfactants. Incorporation of nickel metal into porous sites of TUD-1 enhances its functionality in the detection of humidity. Several techniques such as SAXS, WA-XRD, FESEM with EDX, HRTEM, FTIR, and BET were utilized to verify its structural and chemical properties. The humidity sensing response of TUD-1-x nanocomposites with varying compositions of nickel (x = 0, 1, 5, 10, 15) was investigated, and it was found that the NiO-doped TUD-1 nanocomposites exhibited better responses to different relative humidity levels. Among the different compositions, the sample with x = 10% was found to be a potential candidate with the most promising results due to its enhanced pore diameter of 10.4 nm. Nickel oxide enhances the material's sensitivity to moisture, making it more responsive and efficient in detecting changes in humidity levels. The prime specimen exhibited a remarkable resistance change of 4.1 orders, when tested under specific humidity conditions ranging from 11 to 98% with response and recovery times of 47 and 45 s, respectively.