水热法合成八面体锡酸锌及其电化学性质表征

Hydrothermal Synthesis and Electrochemical Properties of Octahedral Zn_2SnO_4 Compound

采用水热法,以ZnSO4.7H2O,SnCl4.5H2O,NaOH为原料,以表面活性剂十六烷基三甲基溴化铵(CTAB)为辅助剂,合成具有八面体特定形貌的Zn2SnO4化合物.通过X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)和透射电镜(TEM)对产品进行表征.结果表明:所得样品为具有纯相反尖晶石结构的实心八面体Zn2SnO4,单个八面体棱长为500～600nm,化合物中Zn和Sn分别是以+2价和+4价氧化态形式存在.CTAB量对八面体Zn2SnO4形貌起重要作用,其最佳浓度为100 c0(c0为CTAB在水中的临界胶束浓度———0.9×10-3mol/L).八面体Zn2SnO4在电压为0.05～3 V,电流密度为0.2 mA/cm2,首次放电容量达1553.4(mA.h)/g,优于Zn2SnO4纳米颗粒,说明八面体Zn2SnO4在锂离子电池负极材料应用方面具有广阔的前景.

Octahedral Zn2SnO4 compound was synthesized by a hydrothermal method in which ZnSO4·7H2O, SnCl4 · 5H2O, NaOH and surfaetant hexadecyl trimethyl ammonium bromide （CTAB） were used as reactants. The structure, morphology and the surface analysis of the products was characterized by XRD, SEM,TEM and XPS techniques. The results indicated the Zn2SnO4 has an inverse spinel crystal structure and the edge size of the solid octahedra is 500-600 nm. Zinc and tin were found at the ＋ 2 and ＋ 4 oxidation states respectively. The amount of CTAB had an immense effect on the morphology control of octahedral Zn2SnO4. The optimized concentration of CTAB was 100 co （ co is 9 × 10^ -4 mol/L as the critical micelle in water） . The initial specific discharge capacity of the octahedral Zn2SnO4 was 1553.4 （mA· h）/g at a current density of 0.2 mA/cm^2 in the range of 0.05 -3 V,which was much higher than that of the Zn2 SnO4 nanoparticle. This work showed that octahedral Zn2SnO4 is a promising anode material candidate for Li-ion batteries.