Juárez-Marmolejo L, Maldonado-Teodocio B, Montes de Oca-Yemha M G, Romero-Romo M, Ramírez-Silva M T, Arce-Estrada E M, Morales-Gil P, Mostany J, Palomar-Pardavé M
Departamento de Materiales, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180 Col. Reynosa-Tamaulipas, CDMX, C.P. 02200, México.
Departamento de Quı́mica, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco #186, Col. Vicentina, CDMX, C.P. 09340, México.
J Phys Chem B. 2020 May 14;124(19):3973-3983. doi: 10.1021/acs.jpcb.0c01014. Epub 2020 Apr 30.
From electrochemical potentiodynamic and potentiostatic techniques, the electrodeposition mechanism and kinetics of palladium nanoparticles (PdNPs) onto a glassy carbon electrode (GCE), from Pd(II) ions dissolved in the choline chloride-urea deep eutectic solvent (reline) at 343 K, are reported for the first time. From the analysis of the potentiostatic current density transients, using the model developed by Palomar-Pardavé et al. [ , 2005, 50, 4736-4745], it shows that the PdNPs electrodeposition occurs by multiple 3D nucleation and diffusion controlled-growth with the simultaneous reduction of residual water on the PdNPs growing surfaces. This model renders not just the quantification of the palladium nucleation kinetics parameters, but it effectively allows deconvolving the individual contributions to the total current and, thus, from the integration of the plots of these contributions. It was demonstrated that the charge amount of each process depends on the deposition time and applied overpotential. From SEM images, it was possible to verify that the palladium deposits were constituted by PdNPs and from XPS measurements that these PdNPs were formed by a metallic palladium (core) and Pd(OH) (shell).
首次报道了在343 K下，利用电化学动电位和恒电位技术，将溶解于氯化胆碱-尿素低共熔溶剂（reline）中的钯离子（Pd(II)）电沉积到玻碳电极（GCE）上制备钯纳米颗粒（PdNPs）的电沉积机理和动力学。通过使用Palomar-Pardavé等人[，2005，50，4736 - 4745]开发的模型分析恒电位电流密度瞬变，结果表明，PdNPs的电沉积是通过多次三维成核和扩散控制生长，同时PdNPs生长表面的残留水被还原而发生的。该模型不仅可以量化钯成核动力学参数，而且有效地允许对总电流的各个贡献进行去卷积，从而通过对这些贡献的曲线进行积分来实现。结果表明，每个过程的电荷量取决于沉积时间和施加的过电位。通过扫描电子显微镜（SEM）图像，可以验证钯沉积物由PdNPs组成，通过X射线光电子能谱（XPS）测量可知，这些PdNPs由金属钯（核）和Pd(OH)（壳）形成。
