Yue Xinru, Zhang Xiang, Zhang Mengmeng, Du Wei, Xia Haibing
State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.
School of Environment and Material Engineering, Yantai University, Yantai 264005, P. R. China.
Nanoscale. 2023 Mar 2;15(9):4378-4387. doi: 10.1039/d2nr06170h.
In this work, ultra-small core-shell (USCS) Au@AuPt nanoparticles (NPs) with an optimal Pt-to-Au ratio were successfully prepared by the optimal etching treatment of USCS Au@AuPt NPs by Fe(III) ions to remove some exposed Au atoms on their outermost surfaces. The as-prepared USCS Au@AuPt NPs with Fe(III)-etching treatment for 2 h loaded on carbon black as catalysts (USCS Au@AuPt-NP/C catalysts) exhibit superior electrocatalytic activity and durability for both the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) in acidic media. For instance, the overpotential of USCS Au@AuPt-NP/C catalysts toward the HER is 13 mV at a current density of -10 mA cm ( = 13 mV), which is much better than that of commercial Pt/C catalysts ( = 31 mV). Moreover, their mass activity (63.8 A mg) is about 16.4 times larger than that of commercial Pt/C catalysts (3.9 A mg). In addition, they also present better long-term stability. Furthermore, they also show an improved activity toward the ORR in terms of the half-wave potential () (0.89 V RHE), which is more positive by about 38 mV than commercial Pt/C catalysts (0.852 V). In addition, they also show a higher kinetic current density (14.22 mA cm at 0.85 V) and better long-term durability. This etching-treatment strategy can be extended to further improve the catalytic performance of ultra-small Au-based bimetallic or multi-metallic NPs by surface engineering.
在本工作中，通过用Fe(III)离子对超小核壳（USCS）Au@AuPt纳米颗粒（NPs）进行优化蚀刻处理，以去除其最外表面上一些暴露的Au原子，成功制备了具有最佳Pt与Au比例的超小核壳（USCS）Au@AuPt纳米颗粒。经2小时Fe(III)蚀刻处理后负载在炭黑上作为催化剂的USCS Au@AuPt NPs（USCS Au@AuPt-NP/C催化剂）在酸性介质中对析氢反应（HER）和氧还原反应（ORR）均表现出优异的电催化活性和耐久性。例如，USCS Au@AuPt-NP/C催化剂在电流密度为-10 mA cm（=13 mV）时对HER的过电位为13 mV，远优于商业Pt/C催化剂（=31 mV）。此外，它们的质量活性（63.8 A mg）约为商业Pt/C催化剂（3.9 A mg）的16.4倍。此外，它们还具有更好的长期稳定性。此外，就半波电位（）（0.89 V RHE）而言，它们对ORR也表现出更高的活性，比商业Pt/C催化剂（0.852 V）更正约38 mV。此外，它们还表现出更高的动力学电流密度（在0.85 V时为14.22 mA cm）和更好的长期耐久性。这种蚀刻处理策略可扩展到通过表面工程进一步提高超小Au基金属双金属或多金属NPs的催化性能。
