银纳米材料的形貌可控制备及电催化氧还原性能

Shape-Controlled Preparation of Ag Nanomaterials and Their Electrocatalytic Activity toward Oxygen Reduction Reaction

应用多元醇法通过调控NaCl(间接晶种)的量,快捷方便地制备出银纳米线(SNWs)和银纳米粒子(SNPs),采用SEM、EDS、XRD和UV-Vis表征了纳米材料的形貌、元素组成、晶相结构和尺寸分布范围。结果表明,两种银纳米材料形貌均一,均为面心立方晶体结构。通过线性电位扫描法测定发现,SNWs和SNPs在碱性条件下对氧还原反应(ORR)具有不同的电催化活性,SNWs与SNPs对比,其起始还原电位正移70 mV,峰电位正移50 mV,还原峰电流前者是后者的1.8倍。SNWs表现出更好的催化性能。抗醇性能研究表明,SNWs对甲醇具有较好的抗醇性能,而SNPs对乙醇具有较好的抗醇性能,2种纳米材料均对异丙醇的抗醇性能均较差。

Silver nanowires（SNWs） and silver nanoparticles（SNPs） were quickly and easily prepared via a polyol process through regulating the quantity of NaCl. The morphology, composition, structure and size distribution of the nanomaterials were characterized by SEM, EDS, XRD and UV-Vis, respectively. The electro-catalytic performance to oxygen reduction was studied for SNWs and SNPs in alkaline electrolytes with or without alcohol by a linear sweep voltammetry（LSV） method. The results show that two kinds of silver nanomaterials with uniform morphology are the face-centered cubic structure. The LSV results reveal that SNWs and SNPs have different electrocatalytic activity toward oxygen reduction reaction（ORR） under alkaline condition. Compared to SNPs, SNWs＇ onset potential shifts 70 mV positively, and the peak potential shifts 50 mV positively. The reduction peak current of SNWs is 1.8 times higher than that of SNPs. SNWs show better catalytic performance. Alcohol resistance studies show that SNWs have good resistance toward methanol, and SNPs has good resistance to ethanol. The isopropanol resistance of two kinds of nanomaterials is poor.