光化学制备氧化铱纳米粒子过程中添加剂对形貌及其电催化性能的影响

Effect of additives on morphology and electrocatalytic activity of photochemically synthesized iridium oxide nanoparticles

通过引入紫外光照,加速IrCl3在弱碱性环境中的水解,加入一定量的葡萄糖或H2O2作为添加剂,合成了氧化铱(IrOx)纳米团聚物。在反应过程中,定时取样采集紫外-可见消光光谱,对光谱的演变过程进行分析,推测反应的历程。结果显示,加入葡萄糖会显著减缓IrOx的生成,而H2O2对这一过程则无明显影响。反应历程上的差异导致上述两个体系的产物具有完全不同的形貌。透射电镜照片显示,向反应溶液中加入葡萄糖或H2O2,可分别得到准球形和网状的IrOx纳米团聚物,团聚物均由粒径不足2nm的小颗粒聚集而成。而对这两种IrOx纳米团聚物电化学测试结果表明,对于析氧反应,准球形团聚物比网状团聚物展现出更高的电催化活性。

Iridium oxide nanoaggregates have been fabricated by accelerating the hydrolysis of IrC13 in alkalescent condition with glucose or hydrogen peroxide as the additive, through the introduction of UV irradiation. During the reaction, the UV-Vis ex- tinction spectra of the reaction solutions were acquired at fixed intervals, and the evolution of the spectra was analyzed to interpret the reaction process. The results indicate that glucose can significantly retard the generation of IrOn, while H2 02 has little effect on this process. The difference in reaction process between these two systems results in products with different morphologies. Transmission electron microscopy （TEM） images demonstrate that the nanoaggregates obtained in solutions containing glucose or H202 are quasi-spherical or network liked, respectively, both of which are consisted of small particles with diameter less than 2 nm. Furthermore, electrochemical measurements of these IrOx nanoaggregates were conducted, and the result showed that the quasi-spherical nanoaggregates exhibited higher electrocatalytic activity towards oxygen evolution reaction than the network-liked ones.