利用锌渣氧粉碱驱晶化法制备纳米氧化锌紫外吸收剂

Ultraviolet Absorber of Nano Zinc Oxide Synthesised from Zinc Oxide Power with Alkali Driven Crystallization Method

以硫酸为浸出剂,提取锌渣氧粉中的锌,形成精制Zn SO4溶液为锌源,Na OH溶液为沉淀剂,采用低温开放溶液法制备出纳米氧化锌,研究锌碱摩尔比、反应温度、不同初始锌离子浓度对产品晶体结构和形貌的影响,确立控制条件:初始Zn2+浓度0.1 mol·L-1,锌碱摩尔比1∶5,控制62℃条件下恒温搅拌反应1 h,制备出锥形的六方晶系纤锌矿结构纳米氧化锌,颗粒分布均匀,平均粒径为100 nm。Zn O的形成是以负离子四面体Zn O2-2为生长基元,由Zn(OH)2到Zn O"结晶-溶解-再结晶"过程。制备的氧化锌在紫外光区280~400 nm波段有很强的吸收性,在可见光区有较好的透过率,具有良好紫外光遮蔽性和可见光透过性,可作为紫外线吸收剂使用。

Nano zinc oxide(Nano ZnO)was synthesized with low temperature solution method by using sulfuric acid as leaching agent to obtain ZnSO 4 solution as zinc source from zinc oxide powder,NaOH solution as precipitant.The effects of Zn 2+∶NaOH molar ratio,reaction temperature,and initial Zn 2+concentration on the crystal structure and morphology of Nano ZnO were investigated.Nano ZnO with hexagonal wurtzite structure and average particle diameter of 100 nm was observed under the optimal conditions(Zn 2+∶NaOH=1∶5,reaction time of 1 h,reaction temperature of 62℃,initial Zn 2+concentration of 0.1 mol/L).A crystallization-dissolution-recrystallization process happened in the growth of ZnO with tetrahedral ZnO 2-2 as growth unit.The Nano ZnO possess a strong absorptivity in the wavelength coverage of 280-400 nm(ultraviolet region)and good transmittance in visible light region,indicating good UV shielding property and visible light transmittance,which could used for ultraviolet absorber.