A novel hybrid compound [Co（4,4′-bipy）2（H2O）4]（4,4′- H2bipy）2[H2W12O40]5.5H2O has been synthesized from an acidified aqueous solution and characterized by elemental and thermal analyses, IR and UV spectroscopy...A novel hybrid compound [Co（4,4′-bipy）2（H2O）4]（4,4′- H2bipy）2[H2W12O40]5.5H2O has been synthesized from an acidified aqueous solution and characterized by elemental and thermal analyses, IR and UV spectroscopy, and single-crystal X-ray structure determination. Structure analysis indicates that the title compound is of monoclinic, space group C2/c, with a = 21.315（9）, b = 15.303 （7）, c = 24.139（10）/k, β = 105.170（5）°, V= 7599（6）/k3, Mr= 3706.99, Z= 4, F（000） = 6616, Dc = 3.231, μ = 18.395 mm^-1, R = 0.0652 and wR = 0.1594. X-ray crystallographic study shows that the title compound consists of one [Co（4,4′-bipy）2（H2O）4]^2＋ cation, two diprotonated 4,4′-bipyridine molecules, 5.5 water molecules of crystallization, and one metatungstate polyoxoanion [H2W12O40]^6-, which approaches an effective Td point symmetry. TG-DTA analysis indicates that the framework of the metatungstate polyoxoanion is collapsed at 587.0℃.展开更多
A new method for production of ammonium metatungstate (AMT) directly from ammonium tungstate solution—Donnan dialysis method is advanced. Laboratory experiments are conducted by a Donnan dialysis cell with the membra...A new method for production of ammonium metatungstate (AMT) directly from ammonium tungstate solution—Donnan dialysis method is advanced. Laboratory experiments are conducted by a Donnan dialysis cell with the membrane area of 140 mm×200 mm. The result shows that the transformation rate of AMT reaches 370 g WO 3/(m 2·h), the recovery ratio of AMT by the Donnan dialysis method is nearly 100%, and the loss of tungsten is less than 0.2%. It has been proved that the Donnan dialysis method is effective for production of AMT.展开更多
Two types of diacetatozirconic acid-yttria molds which were labeled as ZYW mold(diacetatozirconic acidyttria mold with traces of ammoium metatungstate in the slurry) and ZY mold(diacetatozirconic acid-yttria mold with...Two types of diacetatozirconic acid-yttria molds which were labeled as ZYW mold(diacetatozirconic acidyttria mold with traces of ammoium metatungstate in the slurry) and ZY mold(diacetatozirconic acid-yttria mold without ammonium metatungstate) were prepared by traditional investment casting.The ZYW and ZY molds were sintered in a carbon-reducing atmosphere and in air,respectively,at 1550℃ for 4 h.Interactions between Ti-47Al-2Cr-2Nb(at%) alloys and the molds at 1650℃ for 30 min were studied.The microstructures of the metalmold interfaces and the presence of inclusions and oxygen contamination in the TiAl bulk alloy were analyzed,and the influences of ammonium metatungstate were discussed.The results indicate that WO_(3)releases O into the TiAl melt,introducing tungsten metal into the alloy matrix.The TiAl alloy ingots cast in the ZY molds had the fewest inclusions and the lowest oxygen contamination.展开更多
The tungsten trioxide（WO3） thin films were firstly prepared by spin-coating-pyrolysis methods using the ammonium metatungstate（（NH4）6H2W12O40）DMF/water solution, and successfully applied as the efficient compact...The tungsten trioxide（WO3） thin films were firstly prepared by spin-coating-pyrolysis methods using the ammonium metatungstate（（NH4）6H2W12O40）DMF/water solution, and successfully applied as the efficient compact layers for the planar perovskite solar cells. The influence of the WO3 film thickness and the rinsing treatment of CH_3NH_3 PbI_3 thin film with isopropanol on the photovoltaic performance of the corresponding perovskite solar cells was systematically investigated. The results revealed that the perovskite solar cell with a 62 nm thick WO3 compact layer achieved a photoelectric conversion efficiency of 5.72%, with a short circuit photocurrent density of 17.39 mA/cm^2, an open circuit voltage of 0.58 V and a fill factor of 0.57. The photoelectric conversion efficiency was improved from 5.72% to 7.04% by the isopropanol rinsing treatment.展开更多
基金the Program for New Century Excellent Talent in University of Henan Provincethe Foundation of Educational Department of Henan Province+1 种基金the Natural Science Foundation of Henan Provincethe Natural Science Foundation of Henan University
文摘A novel hybrid compound [Co（4,4′-bipy）2（H2O）4]（4,4′- H2bipy）2[H2W12O40]5.5H2O has been synthesized from an acidified aqueous solution and characterized by elemental and thermal analyses, IR and UV spectroscopy, and single-crystal X-ray structure determination. Structure analysis indicates that the title compound is of monoclinic, space group C2/c, with a = 21.315（9）, b = 15.303 （7）, c = 24.139（10）/k, β = 105.170（5）°, V= 7599（6）/k3, Mr= 3706.99, Z= 4, F（000） = 6616, Dc = 3.231, μ = 18.395 mm^-1, R = 0.0652 and wR = 0.1594. X-ray crystallographic study shows that the title compound consists of one [Co（4,4′-bipy）2（H2O）4]^2＋ cation, two diprotonated 4,4′-bipyridine molecules, 5.5 water molecules of crystallization, and one metatungstate polyoxoanion [H2W12O40]^6-, which approaches an effective Td point symmetry. TG-DTA analysis indicates that the framework of the metatungstate polyoxoanion is collapsed at 587.0℃.
文摘A new method for production of ammonium metatungstate (AMT) directly from ammonium tungstate solution—Donnan dialysis method is advanced. Laboratory experiments are conducted by a Donnan dialysis cell with the membrane area of 140 mm×200 mm. The result shows that the transformation rate of AMT reaches 370 g WO 3/(m 2·h), the recovery ratio of AMT by the Donnan dialysis method is nearly 100%, and the loss of tungsten is less than 0.2%. It has been proved that the Donnan dialysis method is effective for production of AMT.
基金financially supported by the Beijing Natural Science Foundation (No.2164054)the National Natural Science Foundation of China (No.51301005)。
文摘Two types of diacetatozirconic acid-yttria molds which were labeled as ZYW mold(diacetatozirconic acidyttria mold with traces of ammoium metatungstate in the slurry) and ZY mold(diacetatozirconic acid-yttria mold without ammonium metatungstate) were prepared by traditional investment casting.The ZYW and ZY molds were sintered in a carbon-reducing atmosphere and in air,respectively,at 1550℃ for 4 h.Interactions between Ti-47Al-2Cr-2Nb(at%) alloys and the molds at 1650℃ for 30 min were studied.The microstructures of the metalmold interfaces and the presence of inclusions and oxygen contamination in the TiAl bulk alloy were analyzed,and the influences of ammonium metatungstate were discussed.The results indicate that WO_(3)releases O into the TiAl melt,introducing tungsten metal into the alloy matrix.The TiAl alloy ingots cast in the ZY molds had the fewest inclusions and the lowest oxygen contamination.
基金Project supported by the National Natural Science Foundation of China(Nos.51472071,512720616,51072043)the National Basic Research Program of China(No.2011CBA00700)
文摘The tungsten trioxide（WO3） thin films were firstly prepared by spin-coating-pyrolysis methods using the ammonium metatungstate（（NH4）6H2W12O40）DMF/water solution, and successfully applied as the efficient compact layers for the planar perovskite solar cells. The influence of the WO3 film thickness and the rinsing treatment of CH_3NH_3 PbI_3 thin film with isopropanol on the photovoltaic performance of the corresponding perovskite solar cells was systematically investigated. The results revealed that the perovskite solar cell with a 62 nm thick WO3 compact layer achieved a photoelectric conversion efficiency of 5.72%, with a short circuit photocurrent density of 17.39 mA/cm^2, an open circuit voltage of 0.58 V and a fill factor of 0.57. The photoelectric conversion efficiency was improved from 5.72% to 7.04% by the isopropanol rinsing treatment.
