The polyoxometalate particles with Keggin structure, (NH 4) 3PMo 12 O 40 ·9H 2O(1) and (NH 4) 3PW 12 O 40 ·7H 2O(2), were prepared firstly by solid state reaction at room temperature. Their structure, partic...The polyoxometalate particles with Keggin structure, (NH 4) 3PMo 12 O 40 ·9H 2O(1) and (NH 4) 3PW 12 O 40 ·7H 2O(2), were prepared firstly by solid state reaction at room temperature. Their structure, particle sizes and appearances were characterized with elemental analyses, IR, XRD and TEM techniques. The size distribution of nanoparticle 1 is in the range of 5—14 nm, the mean size is 9 nm, and the size distribution of nanoparticle 2 is in the range of 3—12 nm, the mean size is 6 nm. It was found that the product H 2C 2O 4·2H 2O plays a critical role in preventing the nanoparticles from aggregating to large particles.展开更多
Ni(OH)2 including 20%Al was synthesized by solid state reaction. The result of XRD indicated that the sample thus prepared was α Ni(OH)2, and its size and crystalline form were much poorer than those of the sample pr...Ni(OH)2 including 20%Al was synthesized by solid state reaction. The result of XRD indicated that the sample thus prepared was α Ni(OH)2, and its size and crystalline form were much poorer than those of the sample prepared by solution state reaction. TG and DTA curves showed that α Ni(OH)2 began to decompose at higher temperature than β Ni(OH)2. The electrochemical behaviorsof the sample were studied by cyclic voltammetry and constant current charge discharge experiment. It was found that the sample by solid state reaction hadmore excellent electrode reversibility, higher discharge potential and higher discharge capacity.展开更多
文摘The polyoxometalate particles with Keggin structure, (NH 4) 3PMo 12 O 40 ·9H 2O(1) and (NH 4) 3PW 12 O 40 ·7H 2O(2), were prepared firstly by solid state reaction at room temperature. Their structure, particle sizes and appearances were characterized with elemental analyses, IR, XRD and TEM techniques. The size distribution of nanoparticle 1 is in the range of 5—14 nm, the mean size is 9 nm, and the size distribution of nanoparticle 2 is in the range of 3—12 nm, the mean size is 6 nm. It was found that the product H 2C 2O 4·2H 2O plays a critical role in preventing the nanoparticles from aggregating to large particles.
文摘Ni(OH)2 including 20%Al was synthesized by solid state reaction. The result of XRD indicated that the sample thus prepared was α Ni(OH)2, and its size and crystalline form were much poorer than those of the sample prepared by solution state reaction. TG and DTA curves showed that α Ni(OH)2 began to decompose at higher temperature than β Ni(OH)2. The electrochemical behaviorsof the sample were studied by cyclic voltammetry and constant current charge discharge experiment. It was found that the sample by solid state reaction hadmore excellent electrode reversibility, higher discharge potential and higher discharge capacity.
