过渡金属杂多酸PW11M光催化还原制备金纳米粒子及其形貌

以掺杂不同过渡金属离子的Keggin结构杂多酸为光催化剂和还原剂,通过光化学还原法制备金纳米粒子。研究发现,纳米金的形成速度、形貌与杂多化合物中掺杂的过渡金属种类、光照时间以及异丙醇的用量等有很大的关系。相同实验条件下,PW11Zn、PW11Fe的光催化还原速率明显高于PW11Ni、PW11Cu,且前2种杂多化合物容易制得均匀而稳定性好的球形颗粒,而后2种则易形成一些三角形或六边形片状纳米粒子;增加紫外光照时间,一定范围内有利于纳米金的形成及形貌的完整;异丙醇用量的增加可以缩短反应时间,提高纳米颗粒的均匀性和稳定性。

Synthesis and Shapes of Gold Nanoparticles by Using Heteropolyanions Containing Transition Metal as Photocatalysts and Stabilizers

Gold nanoparticles were prepared via a simple photoreduction technique in the presence of Keggin heteropolyacid doped with different transition metals(PW11M),in which the Keggin heteropolyacid acted as reducing agent,photocatalyst and stabilizer.The results indicate that formation rate and morphology of the particles strongly depend on the kind of transition metal doped in the heteropolyacid and the preparing conditions such as irradiation time and propan-2-ol amount.The photoreduction rates of PW11Zn and PW11Fe are faster than those of PW11Ni and PW11Cu.The shapes of the nanoparticles synthesized in the presence of PW11Fe and PW11Zn are nearly uniform spheres,while the morphologies of the nanoparticles synthesized in the presence of PW11Ni and PW11Cu are found to contain a mixture of flat triangular/hexagonal structures as well as spheres.The increases of irradiation time and propan-2-ol amount can make the morphology of the nanoparticles more uniform and shorten the formation time of the nanoparticles.