Nanostructured Metal–Metal Oxides and Their Electrocatalytic Applications

Electrochemical nanotechnologies have witnessed great fundamental advances in the last two decades. The strong interaction between the nanoscience and electrochemistry has led intensified studies on nanostructured materials for electronic, electrochromic, catalytic, and analytical applications. Many researchers have focused on metallic and carbon-based nanomaterials for electrocatalysis, energy conversion systems, and sensor development. The requirement of improvement of the performance of conventional Pt-based catalysts along with the search for low cost alternatives has led to the development of multicomponent catalysis systems. Due to their abundant sources and low cost, transition metal oxides offer a wide range of applications in various fields. However, their performance was found to be dependent on the synthesis procedure. Electrochemical deposition is usually the method of choice not only because this technique is a more practical and economical way for readily producing large uniform oxide thin films but also because the technique provides the controlling of the nature of the deposit by changing the deposition parameters. By this means, a mixed-valent metal oxide (MeOx) film can be produced on a carbon or other substrates, which is believed to be responsible for their catalytic activities. Further improvement in the catalytic performance can be maintained by the combination of hyper-d electronic noble metals, platinum in particular, with hypo-d electronic transition metal oxides. This chapter also covers the recently developed deposition techiques such as electrochemical pulsed deposition (PD). This technique favors the formation of nucleation sites and hence contributes to a high dispersion of the deposits compared to other methods. The performance of the electrode on both anodic and cathodic directions can be further enhanced by decorating with metallic nanoparticles and carbon nanotubes. © 2019 Scrivener Publishing LLC.