Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China; Jiangsu Provincial Key Laboratory of Pulp and Paper Science and Technology, Nanjing Forestry University, Nanjing 210037, China.
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China; Jiangsu Provincial Key Laboratory of Pulp and Paper Science and Technology, Nanjing Forestry University, Nanjing 210037, China.
J Hazard Mater. 2021 Jun 15;412:125096. doi: 10.1016/j.jhazmat.2021.125096. Epub 2021 Jan 9.
Renewable lignocellulosic biomass can be effectively transformed to value-added products, enabling fast growth of related downstream processing. However, valorization of the by-produced cellulose-poor fraction, which is also in large volumes, is only occasionally reported regarding existing technologies. Here, a simple, general, and effective strategy for fabricating graphene quantum dots (GQDs) from the Miscanthus (MC) biorefinery waste consisting of sugars and depolymerized lignin, is developed. This process involves the fast and selective removal of most lignin and hemicellulose based on mild acid hydrotrope fractionation, with followed hydrothermal carbonization. The as-fabricated MC-derived GQDs (M-GQDs) exhibit several advantages such as few-layer graphene-like single crystalline structure, sulfur and nitrogen co-doping, bright fluorescence, excitation-dependent photoluminescence, and long fluorescence lifetime (11.95 ns). Furthermore, M-GQDs present prominent fluorescence reduction in the presence of Fe with good linearity (≤0.995) and very low detection limit (≥1.41 nM). Later, it is found that the observed high sensitivity for Fe is based on a dynamic quenching mechanism, which is caused by the Fe-induced increase in both the energy dissipation and photogenerated electron consumption. This work is anticipated to open new opportunities for promoting the integral valorization of biomass and sensitive fluorometric detection of Fe.
可再生木质纤维素生物质可以有效地转化为高附加值产品，从而促进相关下游加工的快速发展。然而，对于现有技术来说，仅偶尔有报道涉及到对副产物中纤维素含量低但产量大的部分进行增值利用。在这里，开发了一种从由糖和解聚木质素组成的芒草（Miscanthus，MC）生物炼制废物中制造石墨烯量子点（GQDs）的简单、通用且有效的策略。该过程涉及基于温和酸水相分离快速且选择性地去除大部分木质素和半纤维素，随后进行水热碳化。所制备的 MC 衍生 GQDs（M-GQDs）具有几个优点，例如类石墨烯的少层单晶结构、硫和氮共掺杂、明亮的荧光、激发依赖性光致发光和长荧光寿命（11.95 ns）。此外，M-GQDs 在存在 Fe 时表现出明显的荧光降低，具有良好的线性（≤0.995）和非常低的检测限（≥1.41 nM）。后来发现，观察到的对 Fe 的高灵敏度基于动态猝灭机制，这是由 Fe 诱导的能量耗散和光生电子消耗增加引起的。这项工作有望为促进生物质的整体增值利用和对 Fe 的敏感荧光检测开辟新的机会。
