点燃温度对ZnO超细粉体微观形貌和光催化性能的影响

Effects of Ignition Temperature on Morphology and Photocatalytic Performances of Synthesized ZnO Superfine Powder

以蔗糖为燃料、硝酸锌为氧化剂/锌源,采用溶液燃烧法合成ZnO超细粉体。采用XRD、SEM、比表面分析仪和分光光度计等检测设备,研究了点燃温度对合成ZnO粉体的物相组成、微观形貌、比表面积和光催化等性能影响,探讨了合成ZnO粉体对甲基橙光催化的作用机理。结果表明:在点燃温度400～700℃,均可合成棒状的ZnO超细粉体、平均径向尺寸小于150 nm;合成ZnO粉体均具有较高光催化性能,并且在点燃温度为500℃时,合成的ZnO粉体具有最大的比表面积(24.83 m2/g)和最佳的光催化性能,在高压汞灯照射60 min条件下,对甲基橙溶液(10 mg/L)的降解率可达98.2%,且反应符合一级动力学规律。

ZnO superfine powder was synthesized by solution combustion method using sucrose as fuel and Zn （NO3 ）2 as oxidant. The effects of ignition temperature on phase composition, morphology, specific surface area and photocatalytic performance of as-synthesized ZnO were characterized by XRD, SEM, BET and spectrophotometer, etc. The mechanism of as-synthesized ZnO and its photocatalytic performance was investigated. The results show that ZnO with rod-like （less than 150 nm in radial dimension） could be synthesized at ignition temperature 400-700 ℃. Furthermore, as-synthesized ZnO shows better photocatalytic performance. When ignition temperature 500 ℃, synthesized ZnO has the highest specific surface area （24.83 m2/g） and the best photocatalytic ability; photodegradation rate to methyl orange（ 10 mg/L） reaehes 98.2% under the high-pressure mercury lamp irradiation for 60 rain, and reaction may be described as the pseudo first order kinetics equation.