Improved formaldehyde sensor of Zn2SnO4/SnO2 microcubes by compositional evolution and Y2O3 decoration

Zn2SnO4/SnO2 (ZTO/SnO2) and Y doped Zn2SnO4/SnO2 (ZTO/SnO2) microcubes were synthesized by a hydrothermal route at 130 degrees C and subsequently used for obtaining gas sensors. To evaluate the structure, morphology, chemical state and optical bandgap, our sensors were characterized by XRD, SEM, XPS and UV-vis analysis. Compared with sensors based on ZTO/SnO2 microcubes, the Y doped ZTO/SnO2 microcubes had an optimum sensing performance to 100 ppm formaldehyde (HCHO), for instance lower working temperature (210 degrees C) and better response (46.07). In addition, the enhanced sensing mechanism of Y doped ZTO/SnO2 microcubes was discussed in detail.