Inorganic Molecular Imprinting for Mesoporous NaCl Sensing Material

Abstract

The present work demonstrates that the unique properties of mesoporous transition metal oxides enable the efficient synthesis of porous NiO, CuO, Fe2O3, Co3O4 sacrificial templating with NaCl. Mesoporous metal oxides; NiO, CuO, Fe2O3, and Co3O4, templated by NaCl were synthesized successfully by using an evaporation method, which was the principal development of methodology in this project. The structural characterizations of these porous metal oxides were performed by using XRPD, SEM, AFM and N2 adsorption techniques. Phase analysis, purity have been confirmed by X-ray powder diffraction (XRPD) which indicated that all the samples are in single phase. Scanning electron microscopy (SEM) elucidated the morphology as cubic NiO, hexagonal CuO, cubic Fe2O3 and octahedral Co3O4 with average sizes as102, 124, 350 and 275 nm, respectively. AFM study revealed the surface roughness as 89.7, 8.80, 3.52 and 25.5 nm for NiO, CuO, Fe2O3, and Co3O4, respectively. N2 adsorption helped in finding the pore size and pore volume along with the type of adsorption isotherm. The as-synthesized templated metal oxides were used as sensors to find the sensitivity and selectivity against the different concentrations of sodium chloride solution. Evidently, the sensor characteristic is linear with excellent correlation (R2>0.95) within the concentration range 0 to 50 ppm. Keywords. Molecular Imprinting, Salt Templated, NaCl sensor, BET, Evaporation method.