钙钛矿型复合氧化物降解染料废水的性能研究

Study of perovskite type oxide degradation of textile wastewater

以A,B的硝酸盐为原料,以氨水或碳酸钠为沉淀剂,利用混合沉淀的方法合成了系列钙钛矿型氧化物(ABO3).合成中A选碱土金属元素Mg, Ca, Sr, Ba等及稀土金属元素La;B选过渡金属元素Cr, Mn, Fe, Co, Ni等.以酸性红B染料废水为目标物,考察了不同种ABO3复合氧化物光催化活性.活性测试结果表明,A的影响较小,B的影响较显著,总的变化趋势是随着B原子序数的增大光催化活性提高.在上述各催化剂中,SrNiO3的催化活性最高.TEM测试结果显示所合成SrNiO3为纯度较高的粒径为150～200 nm的近球形颗粒.考察了工艺条件对光催化降解酸性红B的影响:在废水溶液中加入H2O2后光催化活性提高,且随着加入量的增大有增长的趋势;提高溶液酸性有利于染料废水降解;酸性红B废水溶液初始质量浓度越高,光催化越难降解.

A series of perovskite oxides are synthesized by means of blend deposition using the nitrate of A and B as the raw materials, and ammonia or sodium carbonate as sedimentation . A includes alkaline,earth metals such as Mg, Ca, Sr, Ba and rare-earth metals La; while B includes transition metal Cr, Mn, Fe, Co and Ni. The results of activity evaluation indicate that the effect of A is low while the effect of B is comparatively remarkable, and the photocatalytic activity improves with the increa- ses of atomic number as a whole. The activity of SrNiO3 is the highest among the above photocatalysts. The test result of TEM shows that the particle shapes an approximately round ball whose diameter is in the range of 150～200 nm. The effects of experimental condition on photocatalytic degradation of acid red B are studied. The photocatalysis is improved by adding H2O2 into the solution and the activity is raised with the increase of the amount of H2O2. Increasing the acidity of the solution helps decompose acid red B. The higher the initial concentration of acid red B, the more difficult the photocatalysis.