以Ag为模板制备Pt纳米空球及其对甲醇氧化的电催化性能

Preparation of Pt Hollow Nanoparticles Using Ag as the Template and Electrocatalytic Performance for Methanol Oxidation

以硝酸银为前驱体,聚乙烯吡咯烷酮(PVP)为表面活性剂,抗坏血酸(AA)为还原剂,在18℃下通过调节氢氧化钠的加入量合成了2种不同粒径的银溶胶;以银溶胶为模板,在室温下合成了不同粒径的铂包银(Ag@Pt)实心纳米粒子;用浓氨水除去Ag核得到球壳上含残留银的铂纳米空球[(Pt-Ag)hollow]及其修饰玻碳(GC)电极[(Pt-Ag)hollow/GC];再用电化学法除去(Pt-Ag)hollow/GC电极上的残留银后,制得铂纳米空球(Pthollow)修饰的GC电极(Pthollow/GC).采用扫描电子显微镜(SEM)、高分辨透射电子显微镜(HRTEM)、能量色散谱仪(EDS)和X射线衍射仪(XRD)等表征了Pthollow的形貌、组成和结构;以甲醇为探针分子,研究比较了Pthollow/GC和实心铂纳米粒子(Ptnano)修饰GC电极(Ptnano/GC)对甲醇氧化的电催化活性.结果表明,Pthollow分散性好,粒径比较均匀;球壳多孔,具有粗糙的内外表面,比表面积大,是由铂原子和多维多级的铂原子团簇构建的结晶度不高的多晶铂;Pthollow/GC对甲醇的电催化氧化活性明显优于Ptnano/GC电极,且大大降低了贵金属Pt的用量.

Ag nanoparticles with two different particle sizes and uniform size-distribution were prepared at 18 ℃ by adjusting the adding amount of the NaOH solution, using silver nitrate as the precursor, polyvinylpyrrolidone（PVP） as the surfactant, ascorbic acid（AA） as the reductant. Pt hollow（Pthollow ） nanospheres with different shell thicknesses and modified glassy carbon （GC） electrode （Pthollow/GC） were synthesized by adjusting the amount of precursor H2PtCl6· 6H2O at room temperature, using Ag colloids as the template. The morphology, composition and structure of Pthollow were characterized by scanning electron microscopy （SEM）, high resolution transmission electron microscopy （HRTEM）, energy-dispersive X-ray spectroscopy （EDS）, X-ray diffraction （XRD） and other detection techniques; the electrocatalytic oxidation activity of Pthollow/GC, Pt solid nanoparticle modified GC （Pt /GC） electrode were studied and compared using methanol as a probe molecule. The results show that the Pthollow nanospheres have a uniform particle size and good dispersity, and the electrocatalytic oxidation activity of Pthollow/GC for methanol is significantly higher than that of Pt /GC electrode.