Tang Mingxin,Qin Cong,Sun Xueya,Li Mengwei,Wang Yihui,Cao Jianliang,Wang Yan
Hydrogen (H 2 ) energy, as a clean energy source, has high energy density and durability, while H 2 is flammable and explosive, which requires strict safety technology measures to ensure the safety of high-pressure storage transportation. Therefore, the development of sensitive sensors is needed. In this study, In 2 O 3 microspheres with different Pd loadings were fabricated by hydrothermal method. Compared with the pristine In 2 O 3 gas sensor, the optimal operating temperature of the In 2 O 3 sensor is reduced from 160 ℃ to 80 ℃ after loading Pd. Among the prepared Pd/In 2 O 3 gas sensors, the response value of the 2 at% Pd/In 2 O 3 sensor towards 1000 ppm H 2 is 50.743 at 80 ℃. The response/recovery time is 80 s/235 s. The improved H 2 sensing performance can be ascribed to the chemical and electron sensitization of Pd, and the formation of PdO, PdH x . This study shows that Pd-loaded In 2 O 3 can effectively reduce the optimal operating temperature and enhance the response value for detecting H 2 in the range of 5-5000 ppm. Therefore, this sensor has good application prospects for detecting H 2 at low temperatures.
For the efficient disposal of organic pollutants and Escherichia coli ( E. coli ) in water, Ag-loaded and Pd-loaded ZnO nanofibers (NFs) were prepared through electrospinning (e-spin), followed by the alcohol-thermal method. The NFs were prepared in membrane form to promote their separation, recovery, and reuse in practical applications. The complete decolorizations of three types of dyes (i.e., azo, triarylmethane, and heterocyclic dyes) were observed when the Ag-loaded or Pd-loaded ZnO nanofiber membrane (NFM) was first applied as photocatalyst under 30-min UV irradiation. The characterization of the catalysts and the decolorization performance of dyes both demonstrated that the optimal loading rates of Ag and Pd were 12% and 6%, respectively. Moreover, the 12%-Ag/ZnO NFM displayed excellent recyclability over five cycles than the 6%-Pd/ZnO NFM. The E. coli disinfection test demonstrated that the photocatalytic inactivation rates with the 12%-Pd/ZnO NFM and the 6%-Ag/ZnO NFM were significantly improved under solar or UV irradiation, and hydroxyl radicals (∙OH) was primarily responsible for the antibacterial performance. Therefore, the presented 12%-Ag/ZnO NFM and 6%-Pd/ZnO NFM can be used for the efficient photocatalytic treatment of dyes and E. coli in water.