以竹炭为载体,采用溶胶-凝胶法制备TiO2溶胶,并掺杂Fe3+,经浸渍过滤和高温焙烧制备Fe3+/TiO2改性竹炭,并用SEM和XRD进行表征。采用单因素和正交组合试验探究焙烧温度、Fe3+掺杂量、负载层数三因子对改性竹炭去除甲醛效果的影响,从而确定制备Fe3+/TiO2改性竹炭的最优工艺。从SEM和XRD图谱表征可知,竹炭、TiO2溶胶和Fe3+三者之间能够较好地复合在一起。三因子中焙烧温度因子最为显著,其次是负载层数和Fe3+掺杂量。制备Fe3+/TiO2改性竹炭最佳工艺参数为焙烧温度450 ℃、负载层数2层、Fe3+掺杂量1%,其对甲醛的去除率达到61%,均高于单一竹炭或TiO2/竹炭复合对甲醛的去除率,表明三者复合具有协同促进作用。
In this study,bamboo charcoal was modified with Fe3+/TiO2 through percolation and high-temperature roasting treatments,and the final product was characterized by SEM and XRD. In the above-mentioned process,bamboo charcoal powder was used as carrier,and TiO2 sol was prepared by a sol-gel method and then intermingled with Fe3+. Both a single factor test and an orthogonal experiment were applied in the investigation to explore the effects of the baking temperature,the Fe3+ content and the number of loading layers on the removal rate of formaldehyde. Based on the data analysis,an optimum process of Fe3+/TiO2 modified bamboo charcoal was then determined. The results showed that bamboo charcoal,TiO2 sol and Fe3+ can be well compounded according to SEM observation and XRD analysis. Among the three chosen factors,baking temperature had the most significant effect on the formaldehyde removal rate. The optimal preparation parameters for the modified bamboo charcoal were as follows: the baking temperature was 450 ℃,the number of load layers were 2,and the Fe3+ content was 1% to achieve the highest formaldehyde removal rate of 61%. This rate is higher than those of bamboo charcoal itself,and modified bamboo charcoal with TiO2 only,which indicates that bamboo charcoal,Fe3+ and TiO2 have a synergistic reaction driving the degradation of formaldehyde.