Palladium nanoparticles assembled on multi-walled carbon nanotubes functionalised by methylene blue under ultraviolet light and electrocatalytic activity for methanol oxidation
Palladium nanoparticles assembled on multi-walled carbon nanotubes functionalised by methylene blue under ultraviolet light and electrocatalytic activity for methanol oxidation
复制标题
DOI：
10.1051/epjap/2014140182
复制
发表时间：
2014-08
影响因子：
1
通讯作者：
Mingli Xu;Yingjie Zhang;Xikun Yang;Shubiao Xia;P. Dong;G. Yang
中科院分区：
文献类型：
--
作者：
Mingli Xu;Yingjie Zhang;Xikun Yang;Shubiao Xia;P. Dong;G. Yang
为了提高直接甲醇燃料电池（dmfc）阳极催化剂的利用率和性能，采用功能化多壁碳纳米管（MWCNTs）作为载体，通过光化学还原法制备钯纳米颗粒。用亚甲基蓝（MB）在紫外光下修饰MWCNTs (f uv -MWCNTs)，然后将Pd纳米粒子组装在f uv -MWCNTs上形成复合材料（Pd/f uv -MWCNTs）。该方法绿色、简单且不会破坏MWCNTs的原始结构。利用透射电子显微镜（TEM）和x射线衍射仪（XRD）对制备的复合材料的形貌和结构进行了表征。结果表明，Pd纳米颗粒具有面心立方晶体结构，尺寸约为3.9 nm，均匀分布在f -MWCNTs表面。x射线光电子能谱（XPS）揭示了f - uv -MWCNTs中存在含n和含s基团。这些基团可能是uv -MWCNTs表面组装Pd纳米粒子的活性位点，并且可以修饰Pd纳米粒子的电子结构。电化学实验表明，制备的Pd/f uv -MWCNTs催化剂具有优异的催化性能。Pd/f uv -MWCNTs对碱性溶液中甲醇氧化的催化活性是商品Pd/C的1.94倍。说明UV辐照能促进MB对MWCNTs的功能化，增强Pd的电子结构修饰，提高Pd/f UV -MWCNTs的催化活性。
In order to improve the utilisation and performance of anode catalysts in direct methanol fuel cells (DMFCs), functionalised multi-walled carbon nanotubes (MWCNTs) are used as a support for palladium (Pd) nanoparticles synthesised by photochemical reduction. MWCNTs are modified by methylene blue (MB) under ultraviolet light (f uv -MWCNTs), and then Pd nanoparticles are assembled on the f uv -MWCNTs to form composites (Pd/f uv -MWCNTs). The method is green, simple and does not destroy the pristine structure of the MWCNTs. The morphology and structure of prepared composites are characterised by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that Pd nanoparticles with face-centred cubic crystal structure are about 3.9 nm in size, and are uniformly dispersed on the surface of f uv -MWCNTs. X-ray photoelectron spectroscopy (XPS) reveals that N-containing and S-containing groups exist in f uv -MWCNTs. These groups might be active sites for assembly of Pd nanoparticles on the surface of f uv -MWCNTs, and can modify the electronic structure of Pd nanoparticles. Electrochemical experiments indicate that the prepared Pd/f uv -MWCNTs catalyst exhibits excellent catalytic performance. The catalytic activity of Pd/f uv -MWCNTs is 1.94 times higher than that of commercial Pd/C for methanol oxidation in alkaline solution. It indicates that UV irradiation can facilitate MB to functionalise MWCNTs, reinforce the modification of the electronic structure of Pd, and enhance the catalytic activity of Pd/f uv -MWCNTs.