Polythiophene-WO3 hybrid architectures for low-temperature H2S detection

This paper describes the low-temperature detection of hydrogen sulphide (H2S) using sensors based on organic–inorganic hybrids. Nanosheet-assembled WO3 architectures were prepared by a facile hydrothermal strategy using citric acid as capping agent. The resultant WO3 was further modified with polythiophene through in-situ polymerization of the adsorbed thiophene monomers on the surface of WO3 framework. The morphology, structure and thermal stability of obtained polythiophene-WO3 (PT-WO) hybrids were investigated in detail by FESEM, XRD, FT-IR, XPS and TG analysis. It is proved that there is a strong bonding interaction between PT and WO3 due to the electron transfer from S to W. Gas-sensing tests show that the PT-WO hybrids exhibit high response, good selectivity and fast recovery to ppm-level H2S at low operating temperature of 70 °C. The improvement of gas-sensing performance is attributed to the formation of p–n junction at the interface between organic PT and inorganic WO3.

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