以乙二醇作为溶剂,采用溶剂热法制备ZnFe 2 O 4,进一步通过控制煅烧温度获得具有不同晶粒尺寸的ZnFe 2 O 4晶体。XRD和SEM分析表明,ZnFe 2 O 4是由纳米尺寸的微晶构成的球状颗粒,粒径约200 nm,属于正尖晶石结构。UV-vis测定表明ZnFe 2 ...以乙二醇作为溶剂,采用溶剂热法制备ZnFe 2 O 4,进一步通过控制煅烧温度获得具有不同晶粒尺寸的ZnFe 2 O 4晶体。XRD和SEM分析表明,ZnFe 2 O 4是由纳米尺寸的微晶构成的球状颗粒,粒径约200 nm,属于正尖晶石结构。UV-vis测定表明ZnFe 2 O 4在紫外及可见光范围均有吸收,禁带宽度为1.60~2.18 eV,制备的温度条件对禁带能隙产生一定的影响。进一步以亚甲基蓝染料为研究对象考察了不同温度条件下制备的ZnFe 2 O 4光催化活性,实验结果表明500℃煅烧的ZnFe 2 O 4具有较高的染料降解率,当染料初始浓度10 mg/L,初始pH为11,催化剂用量为0.04 g/L,300 W汞灯照射2 h,亚甲基蓝的降解率可达到96.8%,降解反应符合一级动力学。由于制备的ZnFe 2 O 4具有磁性,重复使用三次亚甲基蓝的降解率仍可达到83.3%。展开更多
ZnFe2O4 hollow spheres (ZFHs) with sizes of 200-302 nm were synthesized by simple impregnating method using the as-prepared phenolic formaldehyde (PF) spheres as templates and subsequent annealing at 500-700 ℃. The p...ZnFe2O4 hollow spheres (ZFHs) with sizes of 200-302 nm were synthesized by simple impregnating method using the as-prepared phenolic formaldehyde (PF) spheres as templates and subsequent annealing at 500-700 ℃. The prepared ZFHs are assembled by a large number of small nanoparticles with sizes of 15-20 nm, and many mesopores exist among these nanoparticles. The samples annealed at 500-550℃ exhibit a single cubic spinel structure, while higher annealing temperature leads to the formation of hexagonal ZnO and rhombohedral α-Fe2O3 secondary phases. The size of the assembled nanoparticles increases with the increase in annealing temperature. Novel magnetic transformation from paramagnetic to ferrimagnetic is induced by the reduction of annealing temperature and the saturation magnetization significantly increases from 2.3 to 13.5 A·m^2/kg. The effect of the formation of hollow sphere structure on the redistribution of Fe^3+ and Zn^2+ in the spinel structure was studied.展开更多
通过静电纺丝结合高温煅烧制备ZnFe2O4纳米纤维,采用水热反应将其与氧化石墨烯复合制备得到ZnFe2O4/石墨烯复合纳米纤维。X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)和透射电子显微镜法(TEM)等的分析结果表明,制备得到的ZnFe2O4/石...通过静电纺丝结合高温煅烧制备ZnFe2O4纳米纤维,采用水热反应将其与氧化石墨烯复合制备得到ZnFe2O4/石墨烯复合纳米纤维。X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)和透射电子显微镜法(TEM)等的分析结果表明,制备得到的ZnFe2O4/石墨烯复合纳米纤维结晶良好、纤维直径均匀且表面粗糙,并且还原后的石墨烯能够包覆在其表面。以100 m A/g的电流强度充放电时,首次放电比容量为1 865 m Ah/g,经过50次循环后比容量仍高达848 m Ah/g,表现出优异的循环稳定性能,同时大倍率性能也非常优异。ZnFe2O4/石墨烯复合纳米纤维具有高比容量、良好的循环稳定性和优异的大倍率性能等优点,是一种具有应用前景的新型锂离子电池负极材料。展开更多
文摘以乙二醇作为溶剂,采用溶剂热法制备ZnFe 2 O 4,进一步通过控制煅烧温度获得具有不同晶粒尺寸的ZnFe 2 O 4晶体。XRD和SEM分析表明,ZnFe 2 O 4是由纳米尺寸的微晶构成的球状颗粒,粒径约200 nm,属于正尖晶石结构。UV-vis测定表明ZnFe 2 O 4在紫外及可见光范围均有吸收,禁带宽度为1.60~2.18 eV,制备的温度条件对禁带能隙产生一定的影响。进一步以亚甲基蓝染料为研究对象考察了不同温度条件下制备的ZnFe 2 O 4光催化活性,实验结果表明500℃煅烧的ZnFe 2 O 4具有较高的染料降解率,当染料初始浓度10 mg/L,初始pH为11,催化剂用量为0.04 g/L,300 W汞灯照射2 h,亚甲基蓝的降解率可达到96.8%,降解反应符合一级动力学。由于制备的ZnFe 2 O 4具有磁性,重复使用三次亚甲基蓝的降解率仍可达到83.3%。
基金Project(51574293)supported by the National Natural Science Foundation of ChinaProject supported by the Independent Research Program of State Key Laboratory of Powder Metallurgy,China
文摘ZnFe2O4 hollow spheres (ZFHs) with sizes of 200-302 nm were synthesized by simple impregnating method using the as-prepared phenolic formaldehyde (PF) spheres as templates and subsequent annealing at 500-700 ℃. The prepared ZFHs are assembled by a large number of small nanoparticles with sizes of 15-20 nm, and many mesopores exist among these nanoparticles. The samples annealed at 500-550℃ exhibit a single cubic spinel structure, while higher annealing temperature leads to the formation of hexagonal ZnO and rhombohedral α-Fe2O3 secondary phases. The size of the assembled nanoparticles increases with the increase in annealing temperature. Novel magnetic transformation from paramagnetic to ferrimagnetic is induced by the reduction of annealing temperature and the saturation magnetization significantly increases from 2.3 to 13.5 A·m^2/kg. The effect of the formation of hollow sphere structure on the redistribution of Fe^3+ and Zn^2+ in the spinel structure was studied.
文摘通过静电纺丝结合高温煅烧制备ZnFe2O4纳米纤维,采用水热反应将其与氧化石墨烯复合制备得到ZnFe2O4/石墨烯复合纳米纤维。X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)和透射电子显微镜法(TEM)等的分析结果表明,制备得到的ZnFe2O4/石墨烯复合纳米纤维结晶良好、纤维直径均匀且表面粗糙,并且还原后的石墨烯能够包覆在其表面。以100 m A/g的电流强度充放电时,首次放电比容量为1 865 m Ah/g,经过50次循环后比容量仍高达848 m Ah/g,表现出优异的循环稳定性能,同时大倍率性能也非常优异。ZnFe2O4/石墨烯复合纳米纤维具有高比容量、良好的循环稳定性和优异的大倍率性能等优点,是一种具有应用前景的新型锂离子电池负极材料。
