دانلود رایگان مقاله انگلیسی کربن متخلخل نانوساختاری برای ذخیره و تبدیل انرژی الکتروشیمیایی - الزویر 2018

ABSTRACT

The various methods that have been reported for the synthesis of nanostructured carbons are reviewed, emphasizing sol-gel processing, soft-templating and hydrothermal procedures. Hybrid materials can be obtained by incorporation of nanosized carbon components, such as carbon nanotubes or graphene-derived materials. In addition, the carbon surface chemistry can be tuned by functionalization with surface groups and/or by doping with heteroatoms, in order to suit specific applications. Nanostructured porous carbons can play a decisive role towards the development of efficient and cost-effective electrochemical devices for energy conversion and storage. In this article, we focus on novel electrocatalysts for fuel cells and electrolysers, and electrodes for electric double layer capacitors.

Conclusions and outlook

Carbon materials can be produced with a wide range of textures, structures, morphologies and surface chemistries, playing a decisive role towards the development of efficient and cost-effective electrochemical devices for energy conversion and storage. The textural and surface chemical properties of carbon materials can be modified in a controlled way, addressing the needs of the specific applications envisaged. Micro-mesoporous hierarchical carbons can be synthesized by sol-gel, soft-templating and hydrothermal routes. The hazardous compounds traditionally used in these syntheses can be advantageously replaced by carbohydrates and other biomass-derived precursors, with the assistance of nanocarbons such as GO and CNTs. These hierarchical carbons offer more favourable kinetic properties for application in electrochemical devices, when compared with the currently available activated carbons. Composites consisting of nanostructured carbons self-assembled with metal oxides or carbides have been developed as electrocatalysts for the HER. On the other hand, nitrogen-doped and sulphur-doped carbons have demonstrated excellent activities as electrocatalysts for the ORR. This is an extremely active field of research, driven by the need to replace platinum and other noble metals which are hindering the wide-scale implementation of the new energy paradigm based on hydrogen and renewable sources.