Ultrafine Powder CuO was prepared by direct-heating Cu2(OH)2CO3 in differe nt calcination temperatures. XRD, FT-IR, SEM and surface area measurement tech niques were used to investigate the properties of the CuO powde...Ultrafine Powder CuO was prepared by direct-heating Cu2(OH)2CO3 in differe nt calcination temperatures. XRD, FT-IR, SEM and surface area measurement tech niques were used to investigate the properties of the CuO powder. The results sh ow that the decomposition temperature has remarkably effect on crystallite size, morphology, surface structure, IR behavior and activity of the powder for H2O2 decomposition. The major morphology of the particle is fluffy-sphered in the l ower temperature, which is consists of small sheets of crystallite. With the inc reasing of calcination temperature, crystal of CuO grows up, the fluffy-sphere d particle reduces and catalytic activity decreases. FT-IR patterns revealed t hat the absorption of Cu-O and -OH bond in CuO ultrafine powder were red-s hifted.展开更多
Copper oxides were prepared by direct heating and decomposing copper(Ⅱ) salts, such as Cu 2(OH) 2CO 3, Cu(NO 3) 2·3H 2O, Cu 2C 6H 4O 7·2 5H 2O, CuC 2O 4·2H 2O and CuAc 2·H 2O. The phase, surface a...Copper oxides were prepared by direct heating and decomposing copper(Ⅱ) salts, such as Cu 2(OH) 2CO 3, Cu(NO 3) 2·3H 2O, Cu 2C 6H 4O 7·2 5H 2O, CuC 2O 4·2H 2O and CuAc 2·H 2O. The phase, surface area and catalytic activity of the oxides for H 2O 2 decomposition were investigated by means of XRD and BET measurements. It has been demonstrated that the characteristics of copper oxides obtained from different precursors are much different from each other. Monocomponent nano CuO, which has higher catalytic activity for H 2O 2 decomposition, can be prepared by direct heating and decomposing Cu 2(OH) 2CO 3. On the other hand, CuO in the decomposition products of the organic acid copper can be partially reduced to Cu 2O and Cu in the reducing atmosphere, and the Cu 2O component in the products has higher catalytic activity for H 2O 2 decomposition.展开更多
Nanopowder MnO 2 was prepared with two oxidation reduction methods.XRD,SEM,FT IR and surface area measurement techniques were used to investigate properties of the MnO 2 powder.The results showed that the nano MnO 2 w...Nanopowder MnO 2 was prepared with two oxidation reduction methods.XRD,SEM,FT IR and surface area measurement techniques were used to investigate properties of the MnO 2 powder.The results showed that the nano MnO 2 with an average diameter in 30～50nm and good dispersity and high catalytic activity for H 2O 2 decomposition,can be synthesized with the two methods.With reduced crystal size of the powder,the infrared absorption peak of Mn O bond was blue shifted and fissioned,one shifted 61 19cm -1 and the other shifted 11 15cm -1 ,and the characteristic vibration bands of adsorption water were also blue shifted.展开更多
Factors influencing the stability of the red pigment extracting form Haihongguo fruit,a natural fruit,were investigated in this paper.The results showed that the pigment was stable in acid,under the light and heat con...Factors influencing the stability of the red pigment extracting form Haihongguo fruit,a natural fruit,were investigated in this paper.The results showed that the pigment was stable in acid,under the light and heat condition.The food additions such as starch,carbohydrate,ascorbie acid,sucrose,glucose sodium benzoate ect.,have no bad influence on the color quality of the pigment,so did the reace element for human body such as K+,Na+,Ca2+,Zn2+,ect.,However the Fe3+,Sn2+,H2O and Na2SO3,have redox reaction with the pigment and change its color.The exaction of red pigment in the Haihongguo Fruit may provide the new sources for the food addition.展开更多
The title nanocrystalline powders were prepared by sol-gel method, the influences of grain size on crystal structure were investigated by XRD and DSC techniques. The experiment results show that the tetragonal ferroel...The title nanocrystalline powders were prepared by sol-gel method, the influences of grain size on crystal structure were investigated by XRD and DSC techniques. The experiment results show that the tetragonal ferroelectric phase content of the powders and the Curie temperature Tc are increased with the increase of grain size. When the grain size is less than 34. 7nm, crystal structure of the particle changes into cubic paraelectric phase and the transition of ferro-paraelectric phase disappears as well.展开更多
文摘Ultrafine Powder CuO was prepared by direct-heating Cu2(OH)2CO3 in differe nt calcination temperatures. XRD, FT-IR, SEM and surface area measurement tech niques were used to investigate the properties of the CuO powder. The results sh ow that the decomposition temperature has remarkably effect on crystallite size, morphology, surface structure, IR behavior and activity of the powder for H2O2 decomposition. The major morphology of the particle is fluffy-sphered in the l ower temperature, which is consists of small sheets of crystallite. With the inc reasing of calcination temperature, crystal of CuO grows up, the fluffy-sphere d particle reduces and catalytic activity decreases. FT-IR patterns revealed t hat the absorption of Cu-O and -OH bond in CuO ultrafine powder were red-s hifted.
文摘Copper oxides were prepared by direct heating and decomposing copper(Ⅱ) salts, such as Cu 2(OH) 2CO 3, Cu(NO 3) 2·3H 2O, Cu 2C 6H 4O 7·2 5H 2O, CuC 2O 4·2H 2O and CuAc 2·H 2O. The phase, surface area and catalytic activity of the oxides for H 2O 2 decomposition were investigated by means of XRD and BET measurements. It has been demonstrated that the characteristics of copper oxides obtained from different precursors are much different from each other. Monocomponent nano CuO, which has higher catalytic activity for H 2O 2 decomposition, can be prepared by direct heating and decomposing Cu 2(OH) 2CO 3. On the other hand, CuO in the decomposition products of the organic acid copper can be partially reduced to Cu 2O and Cu in the reducing atmosphere, and the Cu 2O component in the products has higher catalytic activity for H 2O 2 decomposition.
文摘Nanopowder MnO 2 was prepared with two oxidation reduction methods.XRD,SEM,FT IR and surface area measurement techniques were used to investigate properties of the MnO 2 powder.The results showed that the nano MnO 2 with an average diameter in 30～50nm and good dispersity and high catalytic activity for H 2O 2 decomposition,can be synthesized with the two methods.With reduced crystal size of the powder,the infrared absorption peak of Mn O bond was blue shifted and fissioned,one shifted 61 19cm -1 and the other shifted 11 15cm -1 ,and the characteristic vibration bands of adsorption water were also blue shifted.
文摘Factors influencing the stability of the red pigment extracting form Haihongguo fruit,a natural fruit,were investigated in this paper.The results showed that the pigment was stable in acid,under the light and heat condition.The food additions such as starch,carbohydrate,ascorbie acid,sucrose,glucose sodium benzoate ect.,have no bad influence on the color quality of the pigment,so did the reace element for human body such as K+,Na+,Ca2+,Zn2+,ect.,However the Fe3+,Sn2+,H2O and Na2SO3,have redox reaction with the pigment and change its color.The exaction of red pigment in the Haihongguo Fruit may provide the new sources for the food addition.
文摘The title nanocrystalline powders were prepared by sol-gel method, the influences of grain size on crystal structure were investigated by XRD and DSC techniques. The experiment results show that the tetragonal ferroelectric phase content of the powders and the Curie temperature Tc are increased with the increase of grain size. When the grain size is less than 34. 7nm, crystal structure of the particle changes into cubic paraelectric phase and the transition of ferro-paraelectric phase disappears as well.
