title: Porous titania with heavily self-doped Ti3+ for specific sensing of CO at room temperature.
abstract: Semiconductor-based sensors have played an important role in efficient detection of combustible, flammable, and toxic gases, but they usually need to operate at elevated temperatures (200 °C or higher). Although reducing the operation temperature down to room temperature is of practical significance, it is still a huge challenge to fabricate room temperature sensors with a low cost. Here we show a novel "self-doping" strategy to overcome simultaneously both difficulties of "high resistance" and "low reaction rate", which have always been encountered for room-temperature operation of semiconductor-based sensors. In particular, a porous crystalline titania with heavily self-doped Ti(3+) species has been prepared by using a porous amorphous TiO2 and urea as the starting materials. The resulting Ti(3+) self-doped TiO2 material serves as an efficient room-temperature gas-sensing material for specific CO detection with fast response/recovery. The self-dopant (Ti(3+)) in the titania material has proved to decrease the resistance of TiO2 significantly on the one hand and to increase the chemisorbed oxygen species substantially, thus enhancing the surface reaction activity on the other. Such a self-doping concept is anticipated to give a fresh impetus to rational design of room-temperature sensing devices with low costs.
authors: School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, PR China.
authors: Juan
authors: J
authors: Su
authors: Xiao-Xin
authors: XX
authors: Zou
authors: Yong-Cun
authors: YC
authors: Zou
authors: Guo-Dong
authors: GD
authors: Li
authors: Pei-Pei
authors: PP
authors: Wang
authors: Jie-Sheng
authors: JS
authors: Chen
mesh_terms: D002248:Carbon Monoxide / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D013499:Surface Properties; D013696:Temperature; D014025:Titanium / Q000737:chemistry*
chemical_list: D002248:Carbon Monoxide; D014025:Titanium