Nanocrystalline SnO<sub>2</sub> and CuO doped with SnO<sub>2</sub> were prepared by the co-precipitation method and characterized for different physiochemical properties and microbiological act...Nanocrystalline SnO<sub>2</sub> and CuO doped with SnO<sub>2</sub> were prepared by the co-precipitation method and characterized for different physiochemical properties and microbiological activity. The composition and morphological formation were characterized by XRD, HRTEM, Raman, FTIR, and UV-vis spectroscopy. The Powder X-ray analysis reveals that Sn4+ ions have substituted the Cu<sup>2+</sup> ions without changing the monoclinic structure of SnO<sub>2</sub> but the average particle size of the SnO<sub>2</sub> and CuO doped SnO<sub>2</sub> samples from 11 and 5 nm respectively. However, it exhibits an inhibiting strong bacterial growth against tested bacterial strains.展开更多
The electrical conductivity of pure CaTiO3 and that containing 0.5~5.0 mole fraction CuO as dopant were measured in the temperature range 291~773 K. The conductivity values varied as a ...The electrical conductivity of pure CaTiO3 and that containing 0.5~5.0 mole fraction CuO as dopant were measured in the temperature range 291~773 K. The conductivity values varied as a function of temperature and dopant concentration. The activation energy in the lower temper- ature range depended on the impurity content while in the high temperature range it indicated a value of energy gap width. The infrared absorption spectra in the range of 100~4000 cm-1 revealed the presence of two main bands at 340 and 570 cm-1 which were assigned to Ti06 oc- tahedral normal mode. Bands in the range of 106~270 cm-1 were due to the vibration of anion TiO3-2. Some bands were observed at higher values due to the presence of lattice imperfections. There was a slight shift in band position with increasing dopant concentration which favors the formation of orthorhombic modification.展开更多
A novel Mo-doped CuO catalyst is developed and used for low-temperature NH_(3)-SCR reaction.Compared with the undoped CuO sample,the Mo doped CuO catalyst shows an increased SCR performance with above 80%NO_(x) conver...A novel Mo-doped CuO catalyst is developed and used for low-temperature NH_(3)-SCR reaction.Compared with the undoped CuO sample,the Mo doped CuO catalyst shows an increased SCR performance with above 80%NO_(x) conversion at 175℃.The XRD and Raman results have confirmed the incorporation of Mo metal ions into CuO lattice to form Mo-O-Cu species which may be related to the enhanced SCR activity.The XPS and UV-vis results reveal the creation of electron interaction between Cu and Mo in this Mo-O-Cu system which provides an increased amount of Lewis and Brønsted acid sites,thereby promoting the adsorption capacity of NH_(3) and NO_(x) as verified by NH_(3)-TPD and NO_(x)-TPD characterization.Besides,it also promotes the formation of oxygen vacancies,leading to the increasing of chemisorbed oxygen species,which improves the NO oxidation to NO_(2) activity.Furthermore,in situ DRIFTS technology was also used to study the reaction mechanism of this Mo doped CuO catalyst.The formed NO_(2) could react with NHx(x=3,2)species to enhance the low-temperature NH_(3)-SCR activity via the"fast-SCR"reaction pathway.The nitrate and nitrite ad-species may react with NH_(3) and NH4^(+)ad-species through the L-H pathway.展开更多
文摘Nanocrystalline SnO<sub>2</sub> and CuO doped with SnO<sub>2</sub> were prepared by the co-precipitation method and characterized for different physiochemical properties and microbiological activity. The composition and morphological formation were characterized by XRD, HRTEM, Raman, FTIR, and UV-vis spectroscopy. The Powder X-ray analysis reveals that Sn4+ ions have substituted the Cu<sup>2+</sup> ions without changing the monoclinic structure of SnO<sub>2</sub> but the average particle size of the SnO<sub>2</sub> and CuO doped SnO<sub>2</sub> samples from 11 and 5 nm respectively. However, it exhibits an inhibiting strong bacterial growth against tested bacterial strains.
文摘The electrical conductivity of pure CaTiO3 and that containing 0.5~5.0 mole fraction CuO as dopant were measured in the temperature range 291~773 K. The conductivity values varied as a function of temperature and dopant concentration. The activation energy in the lower temper- ature range depended on the impurity content while in the high temperature range it indicated a value of energy gap width. The infrared absorption spectra in the range of 100~4000 cm-1 revealed the presence of two main bands at 340 and 570 cm-1 which were assigned to Ti06 oc- tahedral normal mode. Bands in the range of 106~270 cm-1 were due to the vibration of anion TiO3-2. Some bands were observed at higher values due to the presence of lattice imperfections. There was a slight shift in band position with increasing dopant concentration which favors the formation of orthorhombic modification.
基金supported by the National Natural Science Foundation of China(Nos.21806017,21876019)the Fundamental Research Funds for the Central Universities(No.DUT20RC(4)003)National Key Research and Development Program of China(No.2019YFC1903903).
文摘A novel Mo-doped CuO catalyst is developed and used for low-temperature NH_(3)-SCR reaction.Compared with the undoped CuO sample,the Mo doped CuO catalyst shows an increased SCR performance with above 80%NO_(x) conversion at 175℃.The XRD and Raman results have confirmed the incorporation of Mo metal ions into CuO lattice to form Mo-O-Cu species which may be related to the enhanced SCR activity.The XPS and UV-vis results reveal the creation of electron interaction between Cu and Mo in this Mo-O-Cu system which provides an increased amount of Lewis and Brønsted acid sites,thereby promoting the adsorption capacity of NH_(3) and NO_(x) as verified by NH_(3)-TPD and NO_(x)-TPD characterization.Besides,it also promotes the formation of oxygen vacancies,leading to the increasing of chemisorbed oxygen species,which improves the NO oxidation to NO_(2) activity.Furthermore,in situ DRIFTS technology was also used to study the reaction mechanism of this Mo doped CuO catalyst.The formed NO_(2) could react with NHx(x=3,2)species to enhance the low-temperature NH_(3)-SCR activity via the"fast-SCR"reaction pathway.The nitrate and nitrite ad-species may react with NH_(3) and NH4^(+)ad-species through the L-H pathway.
