Balkis Ali, Crawford Jessica, O'Mullane Anthony P
School of Science, RMIT University, Melbourne, VIC 3001, Australia.
School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, QLD 4001, Australia.
Nanomaterials (Basel). 2018 Sep 25;8(10):756. doi: 10.3390/nano8100756.
The electrochemical formation of nanostructured materials is a cost effective route to creating substrates that can be employed in a variety of applications. In this work the surface of a copper electrode was electrochemically restructured in an alkaline solution containing ethanol as an additive to modify the surface morphology, and generate a Cu/Cu₂O surface, which is known to be active for the electrocatalytic reduction of environmentally harmful nitrate ions. To increase the activity of the nanostructured surface it was decorated with gold prisms through a facile galvanic replacement approach to create an active Cu/Cu₂O/Au layer. The surface was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, as well as electrochemical techniques. It was found that the presence of recalcitrant oxides, and Au was beneficial for the increased activity compared to unmodified copper and undecorated restructured copper and was consistent with the incipient hydrous oxide adatom mediator model of electrocatalysis. This approach to generating nanostructured metal/metal oxide surfaces that can be galvanically replaced to create these types of composites may have other applications in the area of electrocatalysis.
纳米结构材料的电化学形成是一种经济高效的途径，可用于制备可应用于各种领域的基底。在本工作中，铜电极表面在含有乙醇作为添加剂的碱性溶液中进行电化学重构，以改变表面形貌，并生成Cu/Cu₂O表面，已知该表面对环境有害硝酸根离子的电催化还原具有活性。为了提高纳米结构表面的活性，通过简便的置换反应方法用金棱镜对其进行修饰，以形成活性Cu/Cu₂O/Au层。采用扫描电子显微镜、能量色散X射线光谱、X射线光电子能谱以及电化学技术对该表面进行了表征。结果发现，与未修饰的铜和未装饰的重构铜相比，难熔氧化物和金的存在有利于活性的提高，这与电催化的初始水合氧化物吸附原子介导模型一致。这种生成纳米结构金属/金属氧化物表面的方法，通过置换反应可制备这类复合材料，可能在电催化领域有其他应用。
