Synthesis, formation mechanism and illuminated sensing properties of 3D WO3 nanowall

Three-dimensional WO3 nanowall was successfully synthesized by a facile solvothermal approach in the solution of F127 template. The effect of solvent on tailoring morphology was investigated in detail. The results show that the products with a diameter of 1–3 μm are actually a kind of nanowall structure, which is composed of high-density nanosheets with about 30 nm in thickness. A possible formation mechanism is proposed here. Sensing properties show that the sensitivity of the three-dimensional WO3 sensor is obviously higher than that of commercial WO3 sensor. UV illumination on three-dimensional WO3 sensor could greatly improve the response because of the formation of defects.