Year

2018

Degree Name

Masters of Philosophy

Department

School of Mechanical, Materials, Mechatronic and Biomedical Engineering

Abstract

Porous materials especially nanoporous carbon, appear especially attractive due to their high specific surface area, well-defined pore structure, high thermal and chemical stability, intrinsic high electrical conductivity, low density and wide availability. In the search for renewable, environmental friendly, cheap, abundant precursors for nanoporous carbon, biomass has been the most promising material, and the nanoporous carbon derived from it has been implemented in energy storage devices and environmental applications, as well as in biomedical sites. Among the various types of biomass, jute fiber, being the world’s second most produced natural fiber, with a 2.8 million metric tons produced each year, had witnessed a great decline in use over the past decade, impacting the livelihoods of over 12 million farmers. Transforming this cheap precursor into high-value -added material with a range of applications has been the main goal.

This thesis firstly highlights the various synthesis route available for transforming cheap biomass into high value added nanoporous carbon, focusing on the merits and demerits of each process. Later, it encompasses the various applications using biomass-derived nanoporous carbon and a detailed comparison of the types of biomass utilized and their relative performance in each category. From this understanding, it was possible to devise a synthesis process, which involved an economically viable and simple physical activation procedure for jute fiber at different temperatures. The optimum temperature of 800◦C yielded a moderately high surface area of 981 m2/g with retention of the original fibrous morphology. This jute-derived nanoporous carbon prepared at 800°C displayed an impressive Methylene blue adsorption capacity of 146 mg/g, comparable to expensive activated carbon yielding 176 mg/g.

This thesis next explores a novel synthetic process which involves pre-carbonization at 300°C, followed by impregnation with KOH and subsequent high temperature chemical activation of three different parts of the jute fiber. It yielded jute–derived activated carbon with an ultra-high surface area in the range of 2682 m2/g. The research then highlights the successful utilization of this nanoporous carbon in supercapacitors, which showed an impressive specific capacitance of 1127 F/g at current density of 1 A/g, and for water treatment application, showed a maximum absorption capacity of 239 mg/g of Methylene blue, as a model containment.

Therefore, this thesis establishes jute as an exciting natural starting material for nanoporous carbon, which is cheap, abundant, and environmentally friendly, for a variety of applications from energy storage to environmental applications, and the scope for a wide range of biomedical uses is yet to be unraveled.

Download

Share

COinS
 

Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.