以水热法合成了Bi_2WO_6纳米花状球,并考察了不同pH值的制备条件下对Bi_2WO_6晶形、形貌、孔径分布、光学性质及催化性能的影响。表征和催化结果表明:在pH值为1的制备条件下,Bi_2WO_6样品为内部有致密空隙的花球,随着pH值的升高,Bi_2WO_...以水热法合成了Bi_2WO_6纳米花状球,并考察了不同pH值的制备条件下对Bi_2WO_6晶形、形貌、孔径分布、光学性质及催化性能的影响。表征和催化结果表明:在pH值为1的制备条件下,Bi_2WO_6样品为内部有致密空隙的花球,随着pH值的升高,Bi_2WO_6的内部孔径变得越来越疏松,当pH值达到7时变为片状;在pH为1、3、5、7条件下合成出的Bi_2WO_6的带隙能在2.14~2.26 e V范围内;光降解Rh B的性能从大到小顺序为pH=7,pH=5,pH=3,pH=1,主要是由于在pH=7制备条件下制备出的Bi_2WO_6衍射峰最强,粉体的晶型发育完整,结晶度高,对Rh B的降解率最高。展开更多
In this study, flower-like mesoporous TiO_2 hierarchical spheres(FMTHSs) with ordered stratified structure and TiO_2 nanoparticles(TNPs) were synthesized via a facile solvothermal route and an etching reaction. Multil...In this study, flower-like mesoporous TiO_2 hierarchical spheres(FMTHSs) with ordered stratified structure and TiO_2 nanoparticles(TNPs) were synthesized via a facile solvothermal route and an etching reaction. Multilamellar vesicles(MTSVs) and unilamellar TiO_2/SiO_2 vesicles(UTSVs) were prepared using cetyltrimethylammonium bromide and didodecyldimethylammonium bromide as structure-directing agents under different solvothermal conditions. FMTHSs and TNPs were obtained from the etching reactions of MTSVs and UTSVs, respectively, in an alkaline system. FMTHSs display flower-like, ordered stratified structures on each petal. The thickness of the ordered stratified structure is approximately3–6 nm, and the number of layers is approximately 2–4. The FMTHSs2 electrode exhibits the first discharge capacity of 212.4 m A h g^(-1) at 0.2 C, which is higher than that of TNPs electrode(167.6 mA h g^(-1)).The discharge specific capacity of FMTHSs2 electrode after 200 cycles at 1 C is 105.9 mA h g^(-1), which is higher than that of TNPs electrode(52.2 mA h g^(-1)) after the same number of cycles. The outstanding performance of FMTHSs2 electrode is attributed to the advantages of FMTHSs. In particular, their own stratified structure can provide additional active sites for reactions. The hierarchical structure can provide short diffusion length for Li^+, large electrolyte–electrode contact area, and superior accommodation of the strain of Li+intercalation/deintercalation.展开更多
文摘以水热法合成了Bi_2WO_6纳米花状球,并考察了不同pH值的制备条件下对Bi_2WO_6晶形、形貌、孔径分布、光学性质及催化性能的影响。表征和催化结果表明:在pH值为1的制备条件下,Bi_2WO_6样品为内部有致密空隙的花球,随着pH值的升高,Bi_2WO_6的内部孔径变得越来越疏松,当pH值达到7时变为片状;在pH为1、3、5、7条件下合成出的Bi_2WO_6的带隙能在2.14~2.26 e V范围内;光降解Rh B的性能从大到小顺序为pH=7,pH=5,pH=3,pH=1,主要是由于在pH=7制备条件下制备出的Bi_2WO_6衍射峰最强,粉体的晶型发育完整,结晶度高,对Rh B的降解率最高。
基金supported by the National Natural Science Foundation of China (Grant Nos.51372134 and 51572124)
文摘In this study, flower-like mesoporous TiO_2 hierarchical spheres(FMTHSs) with ordered stratified structure and TiO_2 nanoparticles(TNPs) were synthesized via a facile solvothermal route and an etching reaction. Multilamellar vesicles(MTSVs) and unilamellar TiO_2/SiO_2 vesicles(UTSVs) were prepared using cetyltrimethylammonium bromide and didodecyldimethylammonium bromide as structure-directing agents under different solvothermal conditions. FMTHSs and TNPs were obtained from the etching reactions of MTSVs and UTSVs, respectively, in an alkaline system. FMTHSs display flower-like, ordered stratified structures on each petal. The thickness of the ordered stratified structure is approximately3–6 nm, and the number of layers is approximately 2–4. The FMTHSs2 electrode exhibits the first discharge capacity of 212.4 m A h g^(-1) at 0.2 C, which is higher than that of TNPs electrode(167.6 mA h g^(-1)).The discharge specific capacity of FMTHSs2 electrode after 200 cycles at 1 C is 105.9 mA h g^(-1), which is higher than that of TNPs electrode(52.2 mA h g^(-1)) after the same number of cycles. The outstanding performance of FMTHSs2 electrode is attributed to the advantages of FMTHSs. In particular, their own stratified structure can provide additional active sites for reactions. The hierarchical structure can provide short diffusion length for Li^+, large electrolyte–electrode contact area, and superior accommodation of the strain of Li+intercalation/deintercalation.
