p–n Heterojunction formation in polyaniline–SnO2 organic–inorganic hybrid composite materials leading to enhancement in sensor functionality toward benzene and toluene vapors at room temperature

•Mutual interaction exists between p-polyaniline and n-SnO2 in their hybrids.•p–n heterojunctions enhance the sensitivity of the hybrid composites.•Correlation exists between p–n heterojunctions and sensor efficiencies.•Fairly efficient sensor materials for benzene and toluene analytes.

Organic–inorganic hybrid composite (OIHC) materials were synthesized through physical grinding of conducting p-polyaniline and n-SnO2 with different weight %. Characterization by FT-IR, XRD, SEM and AC impedance studies revealed a mutual interaction and formation of p–n heterojunctions. In N2 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 40 wt% SnO2 showed 10% sensor efficiency for benzene and slightly higher value for toluene. Considering weak/nil interaction of analyte, the present work produced fairly efficient hybrid sensor materials from almost insensitive organic and inorganic components.

Graphical abstractMutual interaction between conducting p-polyaniline and n-SnO2 in hybrid composite materials results in large number of p–n heterojunctions and enhances their sensor functionality toward benzene and toluene vapors at room temperature. Good correlation exists between number of p–n heterojunctions and sensor efficiencies. Fairly efficient sensor materials are thus developed from almost insensitive organic and inorganic components.Figure optionsDownload full-size imageDownload as PowerPoint slide