title: Effects of functionalization of TiO2 nanotube array sensors with Pd nanoparticles on their selectivity.
abstract: This study compared the responses of Pd-functionalized and pristine titanate (TiO2) nanotube arrays to ethanol with those to acetone to determine the effects of functionalization of TiO2 nanotubes with Pd nanoparticles on the sensitivity and selectivity. The responses of pristine and Pd-functionalized TiO2 nanotube arrays to ethanol gas at 200 °C were ~2877% and ~21,253%, respectively. On the other hand, the responses of pristine and Pd-functionalized TiO2 nanotube arrays to acetone gas at 250 °C were ~1636% and 8746% respectively. In the case of ethanol sensing, the response and recovery times of Pd-functionalized TiO2 nanotubes (10.2 and 7.1 s) were obviously shorter than those of pristine TiO2 nanotubes (14.3 and 8.8 s), respectively. In contrast, in the case of acetone sensing the response and recovery times of Pd-functionalized TiO2 nanotubes (42.5 and 19.7 s) were almost the same as those of pristine TiO2 nanotubes (47.2 and 17.9 s). TiO2 nanotube arrays showed the strongest response to ethanol and Pd functionalization was the most effective in improving the response of TiO2 nanotubes to ethanol among six different types of gases: ethanol, acetone, CO, H2, NH3 and NO2. The origin of the superior sensing properties of Pd-functionalized TiO2 nanotubes toward ethanol to acetone is also discussed.
authors.affiliation: Department of Materials Science and Engineering, Inha University, 253 Yonghyun-Dong, Incheon 402-751, Korea. dswimming@naver.com.
authors.forename: Sunghoon
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Materials Science and Engineering, Inha University, 253 Yonghyun-Dong, Incheon 402-751, Korea. feel2779@naver.com.
authors.forename: Soohyun
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Inha University, 253 Yonghyun-Dong, Incheon 402-751, Korea. dswimming@naver.com.
authors.forename: Suyoung
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Chemistry, Inha University, 253 Yonghyun-Dong, Incheon 402-751, Korea. wanin@inha.ac.kr.
authors.forename: Wan In
authors.initials: WI
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Inha University, 253 Yonghyun-Dong, Incheon 402-751, Korea. cmlee@inha.ac.kr.
authors.forename: Chongmu
authors.initials: C
authors.lastname: Lee
mesh_terms: D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005740:Gases / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D010165:Palladium / Q000737:chemistry*; D010316:Particle Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014025:Titanium / Q000737:chemistry*
chemical_list: D005740:Gases; C009495:titanium dioxide; D010165:Palladium; D014025:Titanium