Polyoxometalate electron acceptor heterogenous dopant into TiO2/g-C3N4 nanofibers for promoted acetone gas detectability

In this work, we synthesized TiO2/g-C3N4/polyoxometalate composite nanofibers by electrospinning method to obtain an effective gas sensitive material utilizing the synergistic effect of the three components. The introduced polyoxometalates (POMs) can work as electrons acceptor and separate electrons and holes, finally improved gas sensing properties. Thus, the composite nanofibers exhibited an enhanced performance for acetone gas detection. Under optimal test condition, the TiO2/g-C3N4/POM-5 % sensor delivered a gas sensing response of 10.53 to 100 ppm acetone gas, which is obviously higher than TiO2/g-C3N4 and pure TiO2 sensor. The response and recovery speed were also accelerated. Selectivity, repeatability and other sensing parameters were systematically investigated. In addition, the mechanism of sensing performance enhancement is analyzed and discussed. This study proved that POMs can separate electrons and holes, finally improved gas sensing properties. This work provides a new idea for the design and construction of high sensitivity TiO2/g-C3N4-based gas sensor by introducting polyoxometalates.