铂基三元合金的可控制备与表征

Controlled synthesis and characterization of Pt based tri-metallic alloy

采用共还原法制备了金-银二元合金纳米胶体,然后以制备得到的金-银二元合金Ag4Au纳米胶体为前驱体,加入氯铂酸,利用银和铂离子之间的置换反应制备出一系列铂含量不同的铂-银-金三元合金纳米胶体。紫外吸收光谱测试结果表明,铂-银-金三元合金纳米胶体的最大吸收峰波长介于Ag4Au(414nm)和PtAu(436nm)的最大吸收峰之间,而且这些合金都有且仅有1个吸收峰,表明产物为均相三元合金。同时铂-银-金三元合金最大吸收峰波长与Pt/(Pt+Au)物质的量比呈线性关系,随铂含量增加最大吸收峰波长向长波方向移动。TEM结果表明合金产物胶体颗粒分布均匀,基本无团聚现象,平均粒径在8～10nm之间。HRTEM结果中出现的晶面间距0.232nm和0.204nm分别与合金的(111)和(200)晶面对应。

Using the alloy of Ag4 Au synthesized by co reduction method and chloroplatinic acid as the precursor, the Pt-Ag-Au al- loys have been prepared through the replacement reaction. UV absorption spectra showed that the maximum absorption wave length of the Pt Ag-Au alloys ranges between Ag4 Au （414 nm） and PtAu （436 nm）. Moreover, these alloys have only one ab- sorption peak, suggesting that the products are homogeneous ternary alloys, rather than a simple mixture of metals. Meanwhile, the maximum absorption wavelength of the Pt-Ag-Au alloys is linearly related to the substance ratio of Pt/（Pt ＋ Au）, and the maximum absorption wavelength will move towards long wave with the increase in the substance ratio. The TEM observation showed that the products were uniform nanoparticles, and the average size is between 8 and 10 nm. The lattice fringes correspond to the spacing of 0. 232 and 0. 204 nm, which match well with the expected d-spacings of the （111） and （200） plane of the alloy, respectively.