High Surface Area Mesoporous Activated Carbon from Hemp Bast Fibre Using Hydrothermal Processing

Abstract

Synthesis of activated carbon from waste biomass is of current interest towards sustainability.The properties of biomass derived activated carbon largely depends on the carbonization process. This study reports preparing extremel high surface area mesoporous activated carbon from hemp bast fibre using hydrothermal processing. Processing in hot water (390-500 o C), then activation using KOH and NaOH was investigated at different loading ratios. The described approach was found to enhance the mesoporosity (centered at 3.0 to 4.5 nm) of the hemp derived activated carbon (HAC) from activation (confirmed by BJH pore size distribution and TEM imaging). BET results showed that the product has an extremely high surface area (2425 m 2 /g) while the surface functional groups (-OH, COOH, C=C/C-C) were confirmed and quantified by XPS and FTIR results. Increasing KOH concentration was found to enhance the surface area with an optimum biochar to KOH ratio of 1:3. The crystallite domain size of HAC was determined using Raman spectroscopy of different wavelengths. The procedure described in this study is an environmentally friendly scalable route for the mass production of activated carbon using hemp fiber.

Anode Performance of Sustainable, Hemp-derived, Flexible, Binder-free, Carbon Fabrics in Lithium-Ion Batteries

“…In addition to these, hemp has been used as a carbon source recently for many systems. In these studies various forms of hemp was used including hemp dust (Rosas, Bedia, Rodríguez-Mirasol, Cordero, research, 2008), hemp hurd (Liu et al, 2017), hemp stem (Yang et al, 2014), hemp canes (Rosas et al, 2008) and hemp fibers (Hossain et al, 2018;Mijailović et al, 2017). The hemp-derived carbon materials obtained from these studies generally showed morphologies such as activated carbon (Liu et al, 2017), activated carbon monoliths (Rosas et al, 2008) and activated carbon fibers (Mijailović et al, 2017), interconnected carbon nanosheets (Wang et al, 2013) As known, activated carbon is generally used to increase the adsorption performance of any system including gas (Liu et al, 2017), water vapor (Rosas et al, 2008), metal (Yang et al, 2014), pesticide (Vukcevic et al, 2012) etc.…”