2020-11-13
设计高性能、低成本的电催化剂是电化学制氢技术的关键。近日，研究室与北京大学曹安源教授课题组合作开发了一种高效析氢催化剂制备技术。该技术通过非稳态热冲击来驱动制备碳纳米管海绵负载的具有位错应变的IrNi纳米粒子(DSIrNi-CNTS)，可将其作为一种高效的析氢反应(HER)催化剂。实验结果表明，自组装出的IrNi纳米粒子中存在着大量的位错，可以诱发应变效应。这种由体缺陷(位错)引起的应变诱导的高能表面结构在催化过程中更有可能抵抗表面重构。因此，该催化剂表现出优异的HER催化活性，在碱性电解液中仅需17 mV的过电位可达到10 mA cm-2的电流密度，超过了目前最先进的Pt/C催化剂。密度泛函理论结果表明，由位错诱导的应变效应可以优化IrNi纳米结构的电子结构，并且可以将HER自由能调整到最佳。论文第一作者为博士生刘思靓，由胡文彬、邓意达、陈亚楠教授共同指导完成。
Figure 1 Schematic illustration of the generation of dislocation by thermal shock progress. a) IrCl3 and NiCl2 were decomposed to Ir and Ni atoms, then went through ultrafast condensation and crytallization in ≈150 ms. Temporal evolution of temperature during the thermal shock exhibited the heating and cooling rates as ≈6100 and 5100 K s-1, respectively. The extra half‐plane of dislocation (highlighted in yellow) formed a strain field in the IrNi nanopaticle. b) The motion of dislocations was kinetically impeded by the lattice distortion (red lines) and millisecond‐class quenching process.
全文链接：https://onlinelibrary.wiley.com/doi/10.1002/adma.202006034
