Facile One-Pot Synthesis of Yolk-Shell Structured Ni Doped Mesoporous Silica and Its Application in Enzyme-Free Glucose Sensor

Yolk-shell structured Ni-doped silica with high specific surface area and excellent thermal stability has been synthesized via a simple surfactant assisted sol-gel mediated hydrothermal method using hexadecyltrimethylammonium bromide (CTAB) as a structure-directing agent in water-ethanol mixed solvent. After calcining off the organic surfactant, the resulting material shows crystallinity in powder X-ray diffraction (XRD) analysis with formation of nickel hydrosilicate phase, Ni₃Si₂O₅(OH)₄. The mesoporosity, nanostructure and morphology of the material have been confirmed by N₂ sorption, transmission (TEM) and field-emission scanning electron microscopic (FESEM) analysis, respectively. Ni-silica yolk-shell nanostructure with around 30 wt% Ni has surface area ca. 500 m²/g with pore width ca. 3.8 nm and 400–500 nm particle size. X-ray photoelectron spectroscopic (XPS) study has also been carried out to confirm the presence of Ni(II) species in the material. This yolk-shell Ni-doped-silica mesostructure has been utilized successfully for non-enzymatic glucose detection at room temperature via electrochemical sensing of D-glucose analyte in 0.1 M NaOH solution.