摘要
溶胶-凝胶法是改性合成TiO_(2)应用最为广泛的一种方法,其改性过程主要集中在溶胶阶段,而干凝胶则被视为合成路径中的关键过渡物,鲜少直接功能化应用。为了拓展干凝胶的环境功能,延长功能材料寿命,先将Ti干凝胶应用于混凝除藻,将混凝作为一种在凝胶阶段改性的方法,随后将混凝后的絮体烘干煅烧合成具可见光响应的TiO_(2)。将乙酰丙酮、乙醇、四氯化钛等搅拌干燥老化,制备钛基干凝胶。将钛基干凝胶作为混凝剂对实验水样进行混凝,对不同初始pH值的含藻水样进行混凝反应,分析反应后的pH值、剩余浊度和Zeta电位,研究Ti基干凝胶除藻效果及混凝改性的作用机理,结果表明Ti干凝胶在混凝过程中形成絮体大,沉降速度快,对高浊度含藻水样的去除率可达到88%,卷扫和网捕是混凝改性的主要作用机理。混凝后的污泥经过干燥后,放入马弗炉中以500℃的温度煅烧4 h得到改性后的TiO_(2),对其进行表征发现改性后的TiO_(2)禁带宽度变小,含有介孔结构,考察其催化活性,发现在可见光下,对橙黄Ⅱ(AO7)的去除率可达90%。这说明,利用钛基干凝胶的混凝反应对材料进行改性是可行的,为延长钛基材料的使用寿命及钛基材料的多功能应用提供了理论依据和技术支持。
The sol-gel method is most widely used for the modification of synthetic TiO_(2),in which the modification usually takes place in the sol phase and the xerogel only serves as an intermediate product in the synthesis process.This study extended the environmental capabilities of xerogel,thereby prolonging the lifespan of functional materials,Ti xerogel was applied to coagulation and algae removal.And coagulation was used as a modification method in the gel phase.Titanium-based xerogel was prepared by stirring,drying,and aging acetylacetone,ethanol,and titanium tetrachloride.The titanium-based xerogel was used as a coagulant in the water samples.Coagulation reactions were conducted on algae-containing water samples with different initial pH values.The pH value,residual turbidity,and Zeta potential after the reaction were analyzed to study the algae removal effects of Ti-based xerogel and the mechanism of coagulation modification.The results showed that Ti xerogel formed large floc in the coagulation process,with fast settling speed,and the removal rate of algae-containing water samples with high turbidity could reach 88%.Sweep flocculation and net trapping were the main mechanisms of coagulation modification.After drying the coagulated sludge,it was placed in a muffle furnace and calcined at 500℃for 4 hours to obtain modified TiO_(2).Characterization revealed that the modified TiO_(2) had a smaller forbidden band width and contained mesoporous structure.Examination of its catalytic activity found that the removal rate of OrangeⅡ(AO7)under visible light could reach 90%,indicating that the modification of materials using coagulation reactions of titanium-based xerogel was feasible.This paper provides theoretical basis and technical support for prolonging the service life of titanium-based materials and their multifunctional applications.
作者
李明慧
宋文玲
潘旻阳
刘晓华
庄新文
LI Minghui;SONG Wenling;PAN Minyang;LIU Xiaohua;ZHUANG Xinwen(Jiangsu Provincial Ecological Assessment Center,Nanjing,Jiangsu 210036,China)
出处
《中国无机分析化学》
CAS
北大核心
2024年第12期1691-1697,共7页
Chinese Journal of Inorganic Analytical Chemistry
基金
江苏省碳达峰碳中和科技创新专项资金资助项目(BE2022861)
江苏省生态环境评估中心自研项目(ZX202403)。
