One-step synthesis of palladium oxide-functionalized tin dioxide nanotubes: Characterization and high nitrogen dioxide gas sensing performance at room temperature

Mesoporous palladium oxide (PdO)-functionalized tin dioxide (SnO2) composite nanotubes (SPCTs) were prepared via one-step synthesis by electrospinning technology using ethanol and N,N-dimethylformamide (DMF) as solvents. Compared with pure SnO2 nanotubes, there were abundant mesopores and multiheterojunctions in PdO-functionalized SnO2 nanotubes. The sample with the molar ratio of SnO2:PdO of 100:3 (3-SPCT) exhibited excellent response (similar to 20.30) as a sensor with fast gas response speed (similar to 1.33 s) to 100 ppm nitrogen dioxide (NO2) at room temperature (RT), and the detection limit reached to 10 ppb. The improved gas sensing performance of the 3-SPCT sensor was mainly attributed to the synergistic effect: the unique SnO2 tubular structure and well-dispersed mesopores provided the gas diffusion and adsorption channels, oxygen defects and chemisorbed oxygen were taken as the electron trap and charge transfer active sites, and a large number of heterojunctions acted as electron transport channels, thereby increasing the transfer rate. (C) 2018 Elsevier Inc. All rights reserved.