形貌可控的钯纳米粒子的电化学制备及电催化性质

Electrochemical Preparation of Shape-controlled Pd Nanoparticles and Their Electrocatalytic Properties

以NaPdCl4为前驱体,以柠檬酸钠为包裹剂,通过两步恒电势法在氧化铟锡(ITO)导电玻璃基底上沉积得到不同形貌的钯纳米粒子(PdNPs).通过调节晶种沉积电势和粒子生长电势、柠檬酸根和溴离子的浓度及反应温度等因素,可以控制PdNPs的形貌、尺寸及在ITO基底上的生长密度;制备出了钯纳米锥阵列及球形、花状和多面体形的PdNPs.研究结果表明,钯纳米锥阵列与其它形状的PdNPs相比,在单位面积ITO基底上具有更大的表面积,表现出对甲醇更强的电化学氧化能力.

The electrochemical preparation of shape-controlled palladium nanoparticles （PdNPs） and their catalytic activity toward methanol electrooxidation were reported. PdNPs were prepared on indium tin oxides （ITO） conductive substrates by a two-step constant potential deposition method, in which Na2PdCl4 and citrate were used as precursor and capping agent. The morphology, size, and growing density of PdNPs can be controlled by varying the electrodeposition parameters, such as nanoseeds generation potential, particle growth potential, the concentration of citrate and bromide, and the deposition temperature. The Pd nanohorn arrays, spherical, flower-like and polyhedronal PdNPs were prepared on ITO substrates. The electrocatalytic properties for methanol oxidation on PdNPs with different morphologies were investigated in alkaline solution. Compared with other PdNPs, the Pd nanohorns demonstrated a much larger surface area on an ITO substrate with a fixed area due to their larger height. As a result, the Pd nanohorn arrays exhibite a higher catalytic activity toward methanol electrooxidation, making them a potential candidate for alkaline direct fuel cell anode materials.