Nd~(3+)掺杂Zno/TiO_2催化剂制备及光催化活性

以ZnSO_4·7H_2O和Ti(SO_4)_2为原料,体积分数40%的乙醇作溶剂,用共沉淀法制备ZnO/TiO_2和Nd~(3+)-ZnO/TiO_2n(zn)∶n(Ti)=3∶10]催化剂。采用XRD和UV-Vis等技术进行表征,考察氨水浓度、Nd~(3+)掺杂量和催化剂用量对罗丹明B光催化降解的影响。XRD分析表明,稀土掺杂使催化剂中纳米TiO_2晶粒细化;UV-Vis吸收光谱表明,稀土元素掺杂后,催化剂在紫外光吸收有所加强;光催化降解实验表明,氨水浓度较低时,所得催化剂活性较高;掺杂适量Nd~(3+)能有效提高ZnO/TiO_2的光催化活性。当催化剂用量1 000 mg·L~(-1)、Nd~(3+)掺杂质量分数0.70%和浓氨水稀释10倍时,太阳光连续光照4 h,催化剂的光催化活性较高,废水COD_(Cr)去除率达90.1%。

Preparation of Nd3+-doped ZnO/TiO2 composite catalyst and its photocatalytic activity

ZnO/TiO2 and Nd^3＋ -ZnO/TiO2 composite catalysts n（Zn）： n（Ti） = 3：10 ] were prepared by coprecipitation method using ZnSO4 · 7H2O and Ti （SO4）2 as raw materials and 40% ethanol（ volume fraction） as solvent and characterized by XRD and UV-vis technique. The influence of ammonia concentration, Nd^3＋ doping amount and photocatalyst dosage on the activity of photocatalysts for rhodamine B degradation was investigated. XRD and UV-Vis results indicated that doing Nd^3＋ made grain refinement of nano-TiO2 and enhanced UV absorption of the composite catalysts. The photocatalytic degradation experimental results showed that the activity of the catalysts prepared with lower ammonia concentration was higher and proper doping Nd^3＋ could effectively improve photocatalytic activity of ZnO/TiO2. The composite catalyst exhibited the higher photocatalytic activity under the condition as follows：catalyst dosage 1 000 mg · L^-1, Nd^3＋ doping mass fraction 0. 70% and V（ ammonia） ： V（water） = 1：10 under the sunlight for 4 h. The removal rate of CODCr reached 90.1%.