Enhanced photoelectric gas sensing performance of SnO2 flower-like nanorods modified with polyoxometalate for detection of volatile organic compound at room temperature

SnO2 has become most popular sensor material because of its excellent optical and electrical properties, but the existence of fast electron-hole recombination in SnO2 material is a critical limitation on developing high-performance gas sensors based on the photoconductive change. Herein, we investigate on polyoxometalate (C4H10ON)23[HN(CH2CH2OH)3]10H2[FeIII(CN)6(α2-P2W17O61CoII)4]·27H2O (abbr. as HPT) doping on SnO2 nanorods for improving gas sensing of formaldehyde and methylbenzene at room temperature (25 °C). The relevant photoconductivity and gas sensing performances demonstrated that the SnO2/HPT composite film had a higher photoconductivity than the pristine SnO2 film. This was attributed to the occurrence of photoinduced electron transfer from SnO2 to HPT, so that the electron-hole recombination in SnO2 could effectively be retarded. Furthermore, the composite film of SnO2/HPT exhibited obvious improvements in photoelectrical gas sensing of formaldehyde and methylbenzene at room temperature. This study represents a new insight into improving the sensing performance of SnO2-based gas sensors by incorporating polyoxometalate.