Title: Surface modification of carbonised waste rice husks by mild hydrothermal treatment

Authors: Wong Min Jin Karen; J.X. Ooi; Zhipeng Wang; Nancy J. Siambun; Willey Y.H. Liew; W.K. Muzammil; K. Sopian; G.J.H. Melvin

Addresses: Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia ' Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia ' Institute of Advanced Materials, Jiangxi Normal University, 99 Ziyang Avenue, Nanchang City, Jiangxi Province, 330022, China ' Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia ' Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia ' Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia ' Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia ' Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia

Abstract: Carbonisation process is a way in exploiting rice husk to produce alternative carbon material. In this study, rice husk was carbonised at 500°C, 2 h in inert environment. Mild hydrothermal treatment of carbonised rice husk was conducted by using potassium hydroxide (KOH) and potassium persulfate (KPS) as reactants in different parameters: 1) the reactants molar ratio; 2) reaction time. The treated carbonised rice husks were tested for its dispersion, morphology observation, elements and functional groups determination. From the results, the modified carbonised rice husks showed improvement in its dispersion with polar solvent while no defects in the structures were observed from the SEM images. High oxygen content was found in EDX analysis for modified carbonised rice husks treated in KOH: KPS with molar ratio of 3:1. The presence of hydroxyl and carboxyl groups from the FTIR spectra shows that the treatment successfully introduced functional group to the carbonised rice husk surface.

Keywords: rice husk; carbonisation; mild hydrothermal; surface modification.

DOI: 10.1504/IJSURFSE.2021.114343

International Journal of Surface Science and Engineering, 2021 Vol.15 No.1, pp.36 - 49

Received: 16 Jun 2020
Accepted: 19 Aug 2020

Published online: 12 Apr 2021 *

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