Polyallylamine-directed green synthesis of platinum nanocubes. Shape and electronic effect codependent enhanced electrocatalytic activity
Polyallylamine-directed green synthesis of platinum nanocubes. Shape and electronic effect codependent enhanced electrocatalytic activity
复制标题
聚烯丙胺引导的铂纳米立方体的绿色合成。
DOI：
10.1039/c3cp44191a
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发表时间：
2013-01-01
影响因子：
3.3
通讯作者：
Xia, Xinghua
中科院分区：
文献类型：
--
作者：
Fu, Gengtao;Wu, Ke;Xia, Xinghua
由于其独特的催化活性，具有可控尺寸和形貌的铂纳米晶的合成引起了人们的极大兴趣。以聚烯丙基胺盐酸盐(PAH)为络合剂、封端剂和小平面选择剂，甲醛为还原剂，采用水热法制备单分散铂纳米立方体(PtNCS)。通过紫外-可见光谱(UV-Vis)、傅里叶变换红外光谱(FT-IR)、透射电子显微镜(TEM)、选区电子衍射(SAED)、X射线衍射(XRD)、X射线光电子能谱(XPS)等手段对纳米铂纳米颗粒的形成机理、颗粒大小和表面组成进行了研究。在所提出的PAH-K2PtCl4-HCHO合成体系中，原料可以重复利用来二次合成铂纳米纳米颗粒，其颗粒大小可以通过控制铂-Ⅱ-PAH络合物中铂-Ⅱ物种的还原速率来控制。经过UV/臭氧和电化学清洗后，由于N-铂的强烈相互作用，残留在铂表面的多环芳烃仍然强烈地影响着铂的d带中心。与商用的E-TEK铂黑相比，所制备的6 nm铂纳米碳黑具有更好的电催化活性(质量活性和比活性)和对氧还原反应(ORR)的稳定性，这是由于小平面效应和电子效应的结合。
The synthesis of Pt nanocrystals with controlled size and morphology has drawn enormous interest due to their particular catalytic activity. We present a facile and green hydrothermal method for synthesizing monodisperse Pt nanocubes (Pt-NCs) with polyallylamine hydrochloride (PAH) as a complex-forming agent, capping agent and facet-selective agent, and formaldehyde as a reductant. The formation mechanism, particle size and surface composition of the Pt-NCs were investigated by Ultraviolet and visible spectroscopy (UV-vis), Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), etc. In the proposed PAH-K2PtCl4-HCHO synthesis system, the raw material could be reutilized to re-synthesize the Pt-NCs, and the particle size of the Pt-NCs could be readily controlled by the reduction rate of the Pt-II species in the Pt-II-PAH complex. After UV/Ozone and electrochemical cleaning, the residual PAH on the Pt-NC surfaces still strongly influenced the d-band centre of Pt due to the strong N-Pt interaction. The as-prepared 6 nm Pt-NCs showed superior electrocatalytic activity (mass activity and specific activity) and stability towards the oxygen reduction reaction (ORR) in both H2SO4 and HClO4 electrolytes compared to the commercial E-TEK Pt black, owing to the combination of the facets effect and electronic effect.