Experimental Investigations and Characterization of Surfactant Activated Mixed Metal Oxide (MMO) Nanomaterial

A wide range of industrial, environmental, and biomedical applications depend greatly on the development of sensitive and reliable humidity sensors. This work reports an extensive investigation of a nanostructured surfactant such as Sodium Dodecyl Sulfate (SDS) and Cetyltrimethyl Ammonium Bromide (CTAB) activated mixed metal oxide (Zinc Oxide / Nickel Oxide) nanomaterial. The crystal study demonstrates an increase in the ZnO/NiO characteristic peaks (101) and (200), due to surface reactive agents. The increment of CTAB molar ratio has significantly increased the crystallite size, such that the bandgap of ZnO/NiO composite is reduced from 3.37eV to 2.80 eV. Brunauer-Emmitt-Teller (BET) surface area study revealed the production of a mesoporous ZnO with an improvement in the specific surface area from 7.82 to 52.01 m²g⁻¹ with a mean diameter reducing from 22.28 to 18.94 nm for the CTAB molar concentration range of 0.0, 0.5, 1.0, 1.5 and 2.0 M namely SC-1, SC-2, SC-3, SC-4, and SC-5 respectively. The internal resistance achieved for the 2M sample is 1 KΩ, which is suitable for better humidity and gas sensing properties. Hence, the proposed ZnO/NiO metal oxide material is more sensitive to a plurality of analytes by providing an increased BET surface area.