Zhiqiang Chen , Mingwei Xia , Ying Gao , Wanli Ma , Yingquan Chen , Xianhua Wang , Hanping Chen , Haiping Yang
{"title":"Study of the effect of nitric acid on the structure and optical properties of alkali lignin-based carbon dots","authors":"Zhiqiang Chen , Mingwei Xia , Ying Gao , Wanli Ma , Yingquan Chen , Xianhua Wang , Hanping Chen , Haiping Yang","doi":"10.1016/j.ccst.2024.100218","DOIUrl":null,"url":null,"abstract":"<div><p>Hydrothermal reactions can convert lignin into carbon dots, and the process often uses acids as additives, but the mechanism of action is not clear. In this study, lignin-based carbon dots were successfully prepared by HNO<sub>3</sub>-assisted one-pot hydrothermal method. The mechanism of the influence of the acidic environment on the structure and optical properties of lignin-based carbon dots was also investigated by changing the addition amount of HNO<sub>3</sub>. It was found that the particle size distribution of carbon dots collected was 1-5 nm, and they could emit bright blue fluorescence under violet light irradiation with the highest fluorescence quantum yield of 10.17%. HNO<sub>3</sub> acts on the branched chains and ether bonds of alkali lignin, prompting the depolymerization of lignin and re-cross-linking and condensation to form lignin-based carbon dots. With the increase of HNO<sub>3</sub> addition, the carbon core of lignin-based carbon dots gradually transformed from amorphous structure to complete graphene-like structure, and the emission wavelength of lignin-based carbon dots shifted from 517 nm to 499 nm, and the fluorescence quantum yield was increased from 2.61% to 10.17% by the effect of integrated N doping, which is of great significance for the analysis of the conformational relationship of lignin-based carbon dots, and for the guidance of the high-efficiency synthesis of lignin-based carbon dots.</p></div>","PeriodicalId":9387,"journal":{"name":"Carbon Capture Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772656824000307/pdfft?md5=2384caa9ccad8e75f0e30b2093a6bbc2&pid=1-s2.0-S2772656824000307-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Carbon Capture Science & Technology","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2772656824000307","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Hydrothermal reactions can convert lignin into carbon dots, and the process often uses acids as additives, but the mechanism of action is not clear. In this study, lignin-based carbon dots were successfully prepared by HNO3-assisted one-pot hydrothermal method. The mechanism of the influence of the acidic environment on the structure and optical properties of lignin-based carbon dots was also investigated by changing the addition amount of HNO3. It was found that the particle size distribution of carbon dots collected was 1-5 nm, and they could emit bright blue fluorescence under violet light irradiation with the highest fluorescence quantum yield of 10.17%. HNO3 acts on the branched chains and ether bonds of alkali lignin, prompting the depolymerization of lignin and re-cross-linking and condensation to form lignin-based carbon dots. With the increase of HNO3 addition, the carbon core of lignin-based carbon dots gradually transformed from amorphous structure to complete graphene-like structure, and the emission wavelength of lignin-based carbon dots shifted from 517 nm to 499 nm, and the fluorescence quantum yield was increased from 2.61% to 10.17% by the effect of integrated N doping, which is of great significance for the analysis of the conformational relationship of lignin-based carbon dots, and for the guidance of the high-efficiency synthesis of lignin-based carbon dots.