Fe-doped WO3 nanoplates with excellent bifunctional performances: Gas sensing and visible light photocatalytic degradation

A series of Fe-doped WO3 nanoplates with various Fe contents (0.5%−5%) were prepared successfully by a facile hydrothermal method. The samples were characterized and their gas sensing and visible light photodegradation properties were investigated systematically. The corresponding reaction mechanisms were proposed based on the experimental results. The results show that the Fe-doped WO3 nanoplates exhibit enhanced gas sensing to acetone and visible light photodegradation to methyl blue (MB). Particularly, the gas sensing response value of the 2 %Fe-WO3 sensor is 2.8 times higher than that of the undoped WO3 sensor. Over a low dosage (10 mg) of the 0.5 %Fe-WO3 catalyst, the photocatalytic degradation rate of the 30 mg L-1 of MB solution reaches as high as 96.8% within a short time (60 min), which is 16.8% higher than that of the undoped WO3. The Fe doping significantly accelerates charge transfer rate of the sample, resulting in the remarkable enhancement in gas sensing response. The excellent photocatalytic activity of the 0.5 %Fe-WO3 may be attributed to the improved charge transfer/separation, the stronger visible light absorption and the lower band-edge potentials. Besides the main active species O2−⋅, ·OH (the secondary active species) also contributes to photodegradation of MB.