Enhanced acetone sensing performance in black TiO2 by Ag modification

The application of TiO2 acetone monitor is highly limited by the high operating temperature and poor sensitivity. In this work, black TiO2 (B-TiO2) is produced by Ti3+ self-doping and is followed by Ag modification to form B-TiO2@Ag. It is first demonstrated that the operating temperature and sensitivity of TiO2 to acetone can be promoted evidently. By introducing a Ti3+ self-doped layer on the surface of TiO2, as observed in TEM images, the band gap of TiO2 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-TiO2@Ag exhibits highest photoelectrical properties. As a result, the B-TiO2@Ag gas sensor with a low operating temperature at 250 degrees C and high response of 68.19 to 50 ppm acetone is realized. The low detection limit of B-TiO2@Ag sensor reaches 887 ppb, which provides an applicable way for non-invasive detection of blood glucose.