Synthesis of PtCuCo Ternary Alloy Using Laser Ablation Synthesis in Solution-Galvanic Replacement Reaction (LASIS-GRR)

Laser ablation synthesis in solution in tandem with galvanic replacement reaction (LASiS-GRR) is a newly-developed, facile and environmental friendly synthesis technique for manufacturing a variety of complex nanostructures including hydroxides, metal/metal oxides nanocomposites (NCs), metal-metal nanoalloys (NAs), core-shell nanostructures, etc. This synthetic technique incorporates both “top-down” pulsed laser ablation synthesis in solution approach (LASiS) and the “bottom-up” chemical reduction method (CRM). The setup houses a Q-switched Nd:YAG pulsed laser (1064 nm) with the laser beam focused at a metal target in liquid medium inside a sealed stainless steel reactor cell. The cell is mounted with a gas inlet/outlet, viewing windows, a stepper motor, thermocouple, injection unit, heating coils, and an ultrasonic dismembrator, which enables accurate laser beam focusing status tuning, temperature, pressure and chemical injection rate control, as well as uniform ablation and real-time de-aggregation. Therefore, the unique advantage of combining CRM with the specific condition inside the liquid-confined plasma plume provided by LASIS to generate novel NPs with tailored morphology and metastable phases is realized. In this study, by carrying out LASiS-GRR on Ni in K2PtCl4 solution, we first produced the nanocomposites composed of PtCuCo alloy embedded in NiO nanomatrices. While after acid wash using HCl at pH2, we successfully removed NiO and produced pure PtCuCo ternary alloy. Both products are potential catalysts for the oxygen evolving reactions. The structures of the aforementioned nanocomposites and nanoalloys were confirmed by transmission electron spectroscopy (TEM) and energy dispersive X-ray spectrum (EDX) element mapping. Furthermore, the detailed composition for the PtCuCo alloys were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES) and characterized by laser-induced breakdown spectroscopy (LIBS).