Recent advances in the energy harvesting device technology using hetero-atom doped carbon nanotubes

Abstract

Carbon nanotubes, graphene, and fullerene are forms of carbon finding widespread applications in numerous fields such as energy storage devices such as batteries and fuel cells, cosmetics, nano-electronics, nano-pharmaceuticals, nano-biotechnology, military devices and equipment, construction, coatings, cutting tools, catalysis and many more. The huge technological advancements, globalization, and never seen industrialization can gain more momentum only with the ready availability of sufficient energy resources and their harvesting. Fossil fuels remained one of the most important primary fuels all over the world and now the shift is towards more use of non-renewable energy resources. At the end of the last century, Svante Arrenius firstly proposed the interconnection between the increased concentration of gases such as CO2 in the atmosphere and the rise in the average temperature through global warming on our planet. This effect gets pronounced effects in various other natural cycles too as observed through various natural events in the 21st century. There are several global warming gases, but the principal emission associated with this change is carbon dioxide. Due to such environmental issues, emphasis is on the use of non-conventional energy sources such as solar, wind, geothermal, ocean, etc. Besides such sources, extensive work is going on the use of fuel cells and modern battery technology using carbon nanotubes (SWCNTs and MWCNTs). Presently, various advanced batteries and fuel cells are being developed using CNTs on an Industrial scale. In the last decade, efforts are taken to control the optical and electronic properties of CNTs incorporating hetero-atom (N, P, Si, S, Al, Ni, etc.) as a dopant for desired structural functionalization. The recent advancements in the field of energy harvesting devices (batteries or fuel cells) using hetero-atom-doped CNTs have been discussed here.