Enhanced acetone sensing performance in black TiO2 by Ag modification

The application of TiO 2 acetone monitor is highly limited by the high operating temperature and poor sensitivity. In this work, black TiO 2 (B-TiO 2 ) is produced by Ti 3+ self-doping and is followed by Ag modification to form B-TiO 2 @Ag. It is first demonstrated that the operating temperature and sensitivity of TiO 2 to acetone can be promoted evidently. By introducing a Ti 3+ self-doped layer on the surface of TiO 2 , as observed in TEM images, the band gap of TiO 2 is reduced to 3.01 eV. Ag surface decoration is carried out for the enhancement of electron generation. Optical absorption and the Hall effect results prove that B-TiO 2 @Ag exhibits highest photoelectrical properties. As a result, the B-TiO 2 @Ag gas sensor with a low operating temperature at 250 °C and high response of 68.19 to 50 ppm acetone is realized. The low detection limit of B-TiO 2 @Ag sensor reaches 887 ppb, which provides an applicable way for non-invasive detection of blood glucose.