摘要
The PdC12 was mixed with nanocrystalline powders LaFeO3 and subsequently followed by an annealing of 800 ℃. PdO phase was formed and almost distributed uniformly on the surface of LaFeO3 nano-particles. With an increase of PdO amounts in composite powders, sensing sensitivity Rg/Ra to low concentration acetone or ethanol for Pd doped LaFeO3 sensors increased at first, underwent the maximum with 2 wt.% PdC12 dopant, and then doped again. Interestingly, appropriate Pd doping in LaFeO3 changed the selectivity behavior of gas sensing. LaFeO3 sensor showed good selectivity to ethanol, but 2 wt.% Pd doped LaFeO3 sensor showed good selectivity to acetone. The sensitivity for LaFeO3 at 200 ℃was 1.32 to 1 ppm ethanol, and 1.19 to 1 ppm acetone. Whereas the sensitivity for 2 wt.% Pd doped LaFeO3 at 200 ℃ was 1.53 to 1 ppm ethanol, and 1.9 to 1 ppm acetone. The 2 wt.% Pd doped LaFeO3 sensor at 200 ℃ showed very short response time （4 s） and recovery time （2 s） to 1 ppm acetone gas, respectively. Such results showed that 2 wt.% Pd doped LaFeO3 sensor is a new promising sensing candidate for detecting low concentration acetone.
The PdC12 was mixed with nanocrystalline powders LaFeO3 and subsequently followed by an annealing of 800 ℃. PdO phase was formed and almost distributed uniformly on the surface of LaFeO3 nano-particles. With an increase of PdO amounts in composite powders, sensing sensitivity Rg/Ra to low concentration acetone or ethanol for Pd doped LaFeO3 sensors increased at first, underwent the maximum with 2 wt.% PdC12 dopant, and then doped again. Interestingly, appropriate Pd doping in LaFeO3 changed the selectivity behavior of gas sensing. LaFeO3 sensor showed good selectivity to ethanol, but 2 wt.% Pd doped LaFeO3 sensor showed good selectivity to acetone. The sensitivity for LaFeO3 at 200 ℃was 1.32 to 1 ppm ethanol, and 1.19 to 1 ppm acetone. Whereas the sensitivity for 2 wt.% Pd doped LaFeO3 at 200 ℃ was 1.53 to 1 ppm ethanol, and 1.9 to 1 ppm acetone. The 2 wt.% Pd doped LaFeO3 sensor at 200 ℃ showed very short response time （4 s） and recovery time （2 s） to 1 ppm acetone gas, respectively. Such results showed that 2 wt.% Pd doped LaFeO3 sensor is a new promising sensing candidate for detecting low concentration acetone.
基金
Project supported by Shandong Natural Science Foundation(ZR2013EMM016)
National Natural Science Foundation of China(51472145,51272133,51472150,J1103212)
the Fundamental Research Funds for the Central Universities(DUT16RC(4)69)
