Production of carbon nanodots from hydrothermal carbonisation of durian shell waste

Carbon dots (CDs) are an emerging nanomaterial that has been used in multidisciplinary areas of energy, environmental and medical fields as a result of its low toxicity, stable and tunable photoluminescence, aqueous solubility and high biocompatibility. In recent years developments in CDs using biom...

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Main Author: Jayaweera, Jayadana Ranathunga Arachchige Supuli
Other Authors: Ng Wun Jern
Format: Thesis-Doctor of Philosophy
Language:English
Published: Nanyang Technological University 2020
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Online Access:https://hdl.handle.net/10356/137327
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spelling sg-ntu-dr.10356-1373272020-11-01T05:00:50Z Production of carbon nanodots from hydrothermal carbonisation of durian shell waste Jayaweera, Jayadana Ranathunga Arachchige Supuli Ng Wun Jern Interdisciplinary Graduate School (IGS) Nanyang Environment and Water Research Institute WJNg@ntu.edu.sg Engineering::Environmental engineering::Waste management Engineering::Materials::Nanostructured materials Carbon dots (CDs) are an emerging nanomaterial that has been used in multidisciplinary areas of energy, environmental and medical fields as a result of its low toxicity, stable and tunable photoluminescence, aqueous solubility and high biocompatibility. In recent years developments in CDs using biomass has gained attention due to the lower cost, high availability and environmentally friendly nature of the latter. In this report durian shell waste (DSW), a lignocellulosic biomass is used to synthesize high fluorescent CDs. Generally, pure cellulose based CDs exhibit poor photoluminescence. However, it is hypothesized that the naturally present oxygen and nitrogen groups in DSW can contribute to the fluorescent enhancement and even provide necessary anchoring points for external doping agents. Thus, this study had aimed to develop a facile synthesis method to convert DSW to high fluorescent CDs, conduct an extractive analysis to identify the various functional groups present in DSW and evaluate the contribution from these functional groups to the photoluminescence, introduce existing and novel dopants to evaluate the effectiveness of these dopants to the optical properties of CDs and finally use the synthesized CDs as a sensor to detect aqueous pollutants. Based on the results, a facile one-pot hydrothermal method was developed to produce CDs from DSW which showed a quantum yield (QY) two times that of pure cellulose. Through the extractive analysis, it was identified amino and carboxylic acids were pivotal to the higher fluorescence. DSW has a higher response to amino groups and this was subsequently used to develop nitrogen doped CDs with a QY of 12.9%. Moreover, doping DSW with nitrogen-metal mix subsequently yielded a QY of 28.9%, which was one of the highest recorded cellulose biomass QYs reported from a one pot hydrothermal technique. The CDs were successfully used as sensors for Fe3+, Mn7+ ions and the antibiotic tetracycline in aqueous systems. Based on the sensitivity and selectivity tests, CDs showed high selectivity for the targeted species and good linear models for Fe3+, Mn7+ and tetracycline were developed with a lowest detection limit of 128 nM, 46.8 nM and 75 nM respectively. The sensing performances of DSW based CDs showed better sensitivity compared with the current fluorescent probes. The mechanisms governing the sensing were further explored. To validate the CDs sensing capabilities, the sensors were applied in real water systems to detect the targeted analyte and the results exhibited good recoveries with acceptable standard deviations. It could be concluded DSW has the potential to be used as a carbon precursor for CD synthesis. The resulting material can be used as an efficient fluorescent probe to detect aqueous pollutants. Doctor of Philosophy 2020-03-17T08:35:10Z 2020-03-17T08:35:10Z 2019 Thesis-Doctor of Philosophy Jayaweera, J. R. A. S. (2019). Production of carbon nanodots from hydrothermal carbonisation of durian shell waste. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/137327 10.32657/10356/137327 en This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0). application/pdf Nanyang Technological University
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Environmental engineering::Waste management
Engineering::Materials::Nanostructured materials
spellingShingle Engineering::Environmental engineering::Waste management
Engineering::Materials::Nanostructured materials
Jayaweera, Jayadana Ranathunga Arachchige Supuli
Production of carbon nanodots from hydrothermal carbonisation of durian shell waste
description Carbon dots (CDs) are an emerging nanomaterial that has been used in multidisciplinary areas of energy, environmental and medical fields as a result of its low toxicity, stable and tunable photoluminescence, aqueous solubility and high biocompatibility. In recent years developments in CDs using biomass has gained attention due to the lower cost, high availability and environmentally friendly nature of the latter. In this report durian shell waste (DSW), a lignocellulosic biomass is used to synthesize high fluorescent CDs. Generally, pure cellulose based CDs exhibit poor photoluminescence. However, it is hypothesized that the naturally present oxygen and nitrogen groups in DSW can contribute to the fluorescent enhancement and even provide necessary anchoring points for external doping agents. Thus, this study had aimed to develop a facile synthesis method to convert DSW to high fluorescent CDs, conduct an extractive analysis to identify the various functional groups present in DSW and evaluate the contribution from these functional groups to the photoluminescence, introduce existing and novel dopants to evaluate the effectiveness of these dopants to the optical properties of CDs and finally use the synthesized CDs as a sensor to detect aqueous pollutants. Based on the results, a facile one-pot hydrothermal method was developed to produce CDs from DSW which showed a quantum yield (QY) two times that of pure cellulose. Through the extractive analysis, it was identified amino and carboxylic acids were pivotal to the higher fluorescence. DSW has a higher response to amino groups and this was subsequently used to develop nitrogen doped CDs with a QY of 12.9%. Moreover, doping DSW with nitrogen-metal mix subsequently yielded a QY of 28.9%, which was one of the highest recorded cellulose biomass QYs reported from a one pot hydrothermal technique. The CDs were successfully used as sensors for Fe3+, Mn7+ ions and the antibiotic tetracycline in aqueous systems. Based on the sensitivity and selectivity tests, CDs showed high selectivity for the targeted species and good linear models for Fe3+, Mn7+ and tetracycline were developed with a lowest detection limit of 128 nM, 46.8 nM and 75 nM respectively. The sensing performances of DSW based CDs showed better sensitivity compared with the current fluorescent probes. The mechanisms governing the sensing were further explored. To validate the CDs sensing capabilities, the sensors were applied in real water systems to detect the targeted analyte and the results exhibited good recoveries with acceptable standard deviations. It could be concluded DSW has the potential to be used as a carbon precursor for CD synthesis. The resulting material can be used as an efficient fluorescent probe to detect aqueous pollutants.
author2 Ng Wun Jern
author_facet Ng Wun Jern
Jayaweera, Jayadana Ranathunga Arachchige Supuli
format Thesis-Doctor of Philosophy
author Jayaweera, Jayadana Ranathunga Arachchige Supuli
author_sort Jayaweera, Jayadana Ranathunga Arachchige Supuli
title Production of carbon nanodots from hydrothermal carbonisation of durian shell waste
title_short Production of carbon nanodots from hydrothermal carbonisation of durian shell waste
title_full Production of carbon nanodots from hydrothermal carbonisation of durian shell waste
title_fullStr Production of carbon nanodots from hydrothermal carbonisation of durian shell waste
title_full_unstemmed Production of carbon nanodots from hydrothermal carbonisation of durian shell waste
title_sort production of carbon nanodots from hydrothermal carbonisation of durian shell waste
publisher Nanyang Technological University
publishDate 2020
url https://hdl.handle.net/10356/137327
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