p-n Heterojunction formation in polyaniline-SnO_2 organic-inorganic hybrid composite materials leading to enhancement in sensor functionality toward benzene and toluene vapors at room temperature

摘要

Organic-inorganic hybrid composite (OIHC) materials were synthesized through physical grinding of conducting p-polyaniline and n-SnCh with different weight %. Characterization by FT-IR, XRD, SEM and AC impedance studies revealed a mutual interaction and formation of p-n heterojunctions. In N_2 atmosphere OIHC materials had enhancement in sensor functionality toward benzene and toluene vapors at room temperature. Good correlation existed between number of p-n heterojunctions and sensor efficiencies. An optimized material with 40wt% SnO2 showed 10% sensor efficiency for benzene and slightly higher value for toluene. Considering weakil interaction of analyte, the present work produced fairly efficient hybrid sensor materials from almost insensitive organic and inorganic components.