水热法CeO_(2)吸附剂的制备及工艺参数优化

Preparation and Process Parameter Optimization of CeO_(2) Adsorbents by Hydrothermal Method

针对目前多采用强碱或强挥发性氨水作为沉淀剂制备微纳米吸附剂存在危害性大、安全性低的问题,以Ce(NO_(3))_(3)·6H_(2)O为铈源、水为溶剂、弱碱性有机化学合物三乙醇胺(TEA)为沉淀剂,采用水热法联合焙烧工艺制备CeO_(2)吸附剂,在不同水热反应温度和TEA添加量的条件下,研究工艺参数对产品物相结构和晶粒尺寸的影响;同时,以吸附率为指标,考察CeO_(2)吸附剂对酸性橙7(AO7)偶氮染料分子的吸附特性,筛选获得制备CeO_(2)吸附剂的最佳工艺参数。结果表明,当Ce(NO_(3))3·6H_(2)O为6 mmol、TEA为6 mmol、水热工艺条件为120℃-24h,焙烧条件为500℃-2h时,所得样品为纯净的CeO_(2)物相;该条件下获得的CeO_(2)对AO7的吸附效率最高,可达99.7%。研究结果对CeO_(2)绿色安全制备方法的建立及其在净化偶氮染料废水中的应用具有指导意义。

In response to the issues of high hazard and low safety associated with the preparation of micro/nano adsorbents for pollutants using strong bases or highly volatile aqueous ammonia as precipitating agents,this paper combined the hydrothermal method and roasting process to prepare the CeO_(2) adsorbent by using Ce(NO_(3))3·6H_(2)O as the cerium source,water as the solvent,and the weakly alkaline organic chemical compound triethanolamine(TEA)as the precipitant.The effects of the process parameters on the physical phase structure and grain size of the final samples were investigated by the gradient design of the hydrothermal reaction temperature(120~200℃)and TEA addition(3~30 mmol).Meanwhile,the adsorption characteristics of the CeO_(2) adsorbent towards the acid orange 7(AO7)azo dye molecules were investigated,and the optimal process parameters for the preparation of CeO_(2) were screened using the adsorption rate as an indicator.The results showed that when Ce(NO_(3))3·6H_(2)O was 6 mmol,TEA was 6 mmol,the hydrothermal process condition was 120℃-24 h,and the roasting condition was 500℃-2 h,the resulting sample was a pure and single CeO_(2) physical phase,and under these conditions,the CeO_(2) adsorbent exhibited the highest adsorption efficiency for AO7,reaching up to 99.7%.The research findings provide guidance for establishing green and safe preparation methods for CeO_(2) adsorbents and their application in purifying azo dye wastewater.