铝掺杂锆酸钕纳米晶的制备以及对甲基橙的催化降解

Preparation and Catalytic Degradation of Methyl Orange on Aluminium Ion Doped Neodymium Zirconate Nanocrystals

摘要: 以硝酸锆、硝酸铝和硝酸钕作为原材料，甘氨酸水溶液和无机盐作为溶剂和分散剂，通过盐助甘氨酸溶液燃烧法(salt-assistant gly combustion method, SGCM)制备了具有立方晶系的烧绿石型铝掺杂锆酸钕纳米晶。产物经X-射线粉末衍射、透射电镜、高分辨电子显微镜、傅里叶变换红外光谱以及拉曼光谱表征。结果表明：钕离子被铝离子部分替代而保持原有烧绿石结构，制得的纳米粒子具有较完美的晶体结构，分散性较好，热处理温度在700℃时单一相的Nd_2−xAl_xZr₂O₇纳米晶已完全形成；所制得的纳米晶由平均粒径为10~30 nm的球状粒子组成，根据Scherrer公式计算出的平均粒径为14.5 nm；从透射电镜照片的(222)面的晶面距为0.305 nm，与理论计算值一致。以光催化降解甲基橙为探针，考察复合产物的催化活性。检测到相对于Nd₂Zr₂O₇而言，Al3+的掺杂可以明显的提高它的催化性能，当nAl:nNd = 1:19时其催化活性最强。 Cubic pyrochlore type aluminium ion doped neodymium zirconate nanocrystals were prepared by salt- assistant gly combustion method (SGCM) with zirconium nitrate, aluminum nitrate and neodymium nitrate as raw materials, glycine as the incendiary agent and inorganic salt as solvent and dispersant. The products were characterized by XRD, TEM, HRTEM, High-resolution electron microscopy, FT-IR and Raman spectrum. The results showed that neodymium ions were partially substituted by aluminium ions, while maintaining the original pyrochlore structure. The obtained nano particles had a perfect crystal structure and good dispersion. Single phase

Nd_2−xAl_xZr₂O₇ nanocrystals al-ready fully formed with the heat treatment temperature in 700°C. The obtained nanocrystals were consisted of spheroidal particles with the average grain size of 10 - 30 nm. According to the Scherrer formula, the calculated mean grain size is 14.5 nm. The crystal plane distance from the (222) plane in the photo of transmission electron microscopy is 0.305 nm, which is consistent with the theoretical calculated value. The catalytic activity of the composite product is determined by the reaction speed of photocatalytic degradation of methyl orange. It is detected that compared to Nd₂Zr₂O₇, the doping of Al3+ can obviously improve its catalytic performance. When nAl:nNd = 1:19, it has the strongest catalytic activity.