碳点的设计合成、结构调控及应用

碳点是一类环境友好且性能独特的纳米粒子, 在光电转换、 生物医学、 催化及储能等领域的研究日益活跃. 碳点主要分为碳量子点(CQDs)、 石墨烯量子点(GQDs)和碳化聚合物点(CPDs), 其中CPDs作为一种新型碳点, 具有合成原料广泛、 碳化程度及共轭结构可调且材料相容性好等优点. 本文综合评述了近年来碳点尤其是CPDs的合成方法; 阐述了通过选择前驱体分子、 控制反应条件及掺杂原子等手段实现对其碳化和共轭程度、 晶格和能级结构的调控, 从而建立碳点及其杂化与复合材料微纳结构与性能之间的关系; 最后, 介绍了碳点在生物标记与成像、 光(电)催化、 光电转换及储能等领域的应用, 并对碳点领域的发展前景进行了展望.     

水热炭化制备碳量子点及其应用

碳量子点作为新兴的“零维”碳纳米材料引起人们广泛的关注。水热炭化法是目前为止应用最广泛的碳量子点合成方法之一。水热炭化合成碳量子点取材广泛、过程简单,其最大的特点是合成的碳量子点表面含有丰富的含氧官能团,水溶性优异,在制备过程中即可对碳量子点进行表面功能化改性。此外,水热法合成的碳量子点具有石墨或无定形结构的碳核。水热碳量子点的结构和性质主要受原料种类及制备条件（水热炭化温度、时间及化学添加剂）的影响,产物在光催化技术、分析检测、活体成像和细胞标记、发光二极管（LED）及药物输送等领域展示出较好应用效果。本文综述了水热碳量子点的制备、性质、形成机理（包括原料的脱水、聚合、炭化及钝化过程）及发光机理（表面缺陷态效应和量子尺寸效应）,并对水热碳量子点的应用进行了总结。最后,对水热碳量子点发展过程中尚待解决的问题进行总结,对其未来的发展方向进行了展望。     

荧光碳点的生物效应及其应用研究进展

作为碳纳米材料的新成员,荧光碳点自发现以来以其独特的光学性能和生物效应引起了人们广泛的关注.新型荧光碳点表面经过钝化修饰后,被赋予相关的反应活性及靶向选择性.此外,荧光碳点更具有较低细胞毒性及优异的生物相容性,使碳点的应用日益多样化,特别在生物医学领域具有广阔的应用前景.本文对荧光碳点在生化分析、微生物检测、生物成像及疾病诊断治疗上的应用研究进展做了详细的论述.     

碳量子点及其性能研究进展

碳量子点(Carbon Quantum Dots,CQDs)是一种新型的碳纳米材料,因其强的量子限域效应和稳定的荧光性能等一系列优异性能,吸引了化学、物理、材料和生物等各领域科学家的广泛关注。相比传统半导体金属量子点,CQDs还具备优异的低毒性和生物相容性,更拓宽了其在生物领域内的研究前景。本文简要地介绍了CQDs的制备方法,主要包括自上而下和自下而上两个方向。除此之外,本文综述了CQDs突出的物理化学性质和性能,包括CQDs的荧光性能、生物相容性和上转换效应,并对CQDs在其在生物成像上的应用进行了归纳。     

基于Cite Space的碳量子点研究热点及趋势可视化分析

利用Cite Space软件梳理了碳量子点领域1998～2021年期间3465篇文献的主要研究信息（国家、机构、作者）,归纳了该领域的研究主题及热点。碳量子点作为一种具有良好荧光性能的碳纳米材料,在荧光检测、传感器、光催化降解等方面得到广泛应用。2011～2021年,碳量子点领域研究呈现高速发展态势。中国科学院、苏州大学及江苏大学等机构的学者在该领域的学术研究十分活跃。该领域的研究主题及热点呈现阶段性特点,2003～2007年,研究主题是碳量子点合成,研究热点是碳量子点的反应活性和转化率;2008～2012年,研究主题是碳量子点合成及发光机理,研究热点是碳量子点的光致发光机理和光催化降解;2013～2017年,研究主题是碳量子点绿色合成和传感器应用,研究热点是碳量子点传感器和检测应用;2018年至今,研究主题是碳量子点传感器以及复合碳量子点材料对有机污染物的光催化降解性能,研究热点是碳量子点在生物传感器,生物检测等领域的应用开发。     

发光碳量子点的合成及应用

碳元素是地球上所有已知生命的基础.由于其具有多样的电子轨道特性(sp、sp²、sp³),因此形成许多结构和性质奇特的物质.碳量子点是2004年发现的一种新型碳材料,相对于传统的半导体量子点和有机染料,这位碳家族中的新成员不仅保持了碳材料毒性小、生物相容性好等优点,而且还拥有发光范围可调、双光子吸收截面大、光稳定性好、无光闪烁、易于功能化、价廉、易大规模合成等无可比拟的优势.虽然在某些性能方面,稀土荧光纳米颗粒可以与之媲美,但是稀土元素昂贵的价格极大地限制了其在实际生产中的应用.因此,对碳量子点这一新兴领域的研究必将对材料科学的发展产生重大影响,它也会为碳家族赢得更多的荣耀.本论文的主要工作是建立了一步合成高荧光量子效率碳量子点的合成方法;对碳量子点的表面进行功能化;制备了碳量子点薄膜、块体和流体材料。     

碳点的高性能化和功能化改性:方法、特性与展望

碳点作为一种新型碳纳米材料,由于其出色的光学性能、低毒性、良好的生物相容性和易修饰性而被广泛应用于各个领域。为了满足不同领域的需求,几种用以调控碳点光学性能的方法已被提出,例如杂原子掺杂、半导体量子点掺杂、聚合物钝化和改性以及主-客体构建。其中,杂原子掺杂是通过单原子或多原子引入电子给体或受体改变其相邻碳原子的电子密度来增加荧光强度;半导体量子点也可与碳点进行复合提升电子分离效率而起到荧光增强的效果;就聚合物改性而言,聚合物不仅可以对碳点表面实施钝化和功能化,而且其固态(或固化)薄膜可以提供紧密的空间促进碳点表面的辐射跃迁起到荧光增强的效果。此外,由碳点-染料和多孔材料-碳点构成的两种主要的主-客体结构中,前者不仅对碳点的荧光发射强度有着促进的作用,更使得碳点具备了显著的红/近红外荧光发射性能,后者对固态发光碳点不仅提供了可能性和设计的灵活性,且为打开碳点新的应用领域提供了机会。本文将围绕四种碳点功能化的方法逐步展开讨论,并介绍相应碳点的光学性能、发光机理和潜在应用;论述功能化碳点的研究现状,并展望功能化碳点的研究方向。     

碳点在润滑领域中的应用

各种形式的摩擦和磨损不仅消耗了全球20%以上的能源,而且造成大量设备损坏。因此,开发减摩抗磨润滑材料对节约能源、延长机械设备使用寿命具有重要意义。碳点是一种新型的碳纳米材料,被广泛应用于化学传感、生物成像、催化、光电器件等领域。近年来,大量研究探索了碳点在工业润滑、微/纳米电子机械系统润滑、生物润滑等润滑领域的应用,证明了碳点具有优异的摩擦学性能,具备巨大潜力成为下一代绿色高效的减摩抗磨润滑材料。然而,至今仍缺乏碳点在润滑领域应用的系统性总结论述。因此,本文对碳点在润滑领域应用的研究进展作了全面系统综述。首先,详细介绍了碳点作为纳米添加剂和润滑涂层的润滑效果及提升其润滑性能的3种策略(尺寸形状控制、表面修饰、杂原子掺杂);然后,全面分析了碳点的润滑机理;最后概述了碳点在润滑领域应用所面临的主要挑战。     

基于碳量子点的绿色合成及生物成像研究进展EI北大核心CSCD

碳量子点(CQDs)作为碳纳米材料家族成员之一,因其原材料广、成本低廉、较高的光致发光性能和良好的生物相容性,在研究和应用领域都受到了广泛的关注,是应用于生物成像的理想材料。CQDs的绿色合成是指采用环保型或无毒型原料,通过绿色合成方法,如炭化法、微波法、水热法等,合成具有荧光性能的无毒碳量子点,与传统的化学氧化、激光烧蚀、热解处理等方法相比,更加绿色环保、经济,其应用已成为研究热点。本文对碳量子点材料特性、绿色合成过程机理、绿色合成原料来源、合成方法,及其在癌细胞、微生物细胞等细胞成像方面的应用进行了综述,探讨了绿色合成CQDs的利弊问题,并提出了今后该研究领域面临的机遇与挑战。     

基于量子点的检测技术在法庭科学物证鉴定中的应用研究进展

由于具有独特的纳米尺寸效应和高灵敏度的光电效应,碳量子点以及半导体量子点技术已经被广泛应用于材料科学、生物和医药等领域。本文在简述量子点结构、合成方法等基础上,着重介绍了基于量子点的检测技术在法庭科学领域毒物、毒品和微量物证鉴定中的应用,旨在分析基于量子点的检测技术研究与应用现状,展望其在法庭科学领域中的应用前景。     

Carbon quantum dots-based semiconductor preparation methods,applications and mechanisms in environmental contamination

Photocatalyst is the most widespread method in advanced oxidation technologies, but due to the photo-induced electron combine easily with hole and the wavelength of adsorption is limited which will affect some practical applications. Carbon quantum dots (CQDs) is non-toxic and harmless green materials, it has the ability to improve the photocatalytic effect which is attributed to its good electrical and optical properties. Their up-conversion effect, photosensitization and electrical conductivity are assistants which help promote the photocatalytic effect in environmental applications. The key mechanisms of CQDs to improve photocatalysis can be roughly divided into three categories: 1) Up-conversion effect converts the incident light into the emitted light with high energy to solve the problem which is the light absorption range; 2) CQDs act as a photosensitizer instead of valence band to provide electrons to the conduction band of semiconductor; 3) CQDs can be used as the internal or external electronic conductor in materials to alleviate the trend of electron and hole separation. However, CQDs and CQDs-based photocatalysts have different views to solve environmental problems, so it is necessary to integrate different views. Therefore, this review is mainly aimed at the recent researches about the preparation processes of CQD, CQDs-based photocatalysts, and their ability to remove environmental pollutants, with a special emphasis on the mechanism for depredating pollutants. Furthermore, this paper analyzes and discusses the prospects and challenges of CQDs in the environmental field.     

Bio-safety assessment of carbon quantum dots,N-doped and folic acid modified carbon quantum dots: A systemic comparison

The carbon quantum dots(CQDs) and their functionalized materials are promising in biomedical field because of their unique properties;meanwhile,a growing concern has been raised about the potential toxicity of these modified materials in biosystem.In this study,we synthesized original CQDs and two common functionalized CQDs including N-doped CQDs(NCQDs) and folic acid-modified CQDs(FACQDs),and compared the toxicity and biocompatibility with each other in vitro and in vivo.L929,C6 and normal cell MDCK were selected to detect the adverse reaction of these materials in vitro.No acute toxicity or obvious changes were noted from in vitro cytotoxicity studies with the dose of these CQD materials increasing to a high concentration at 1 mg/mL.Among these materials,the FA-CQDs show a much lower toxicity.Moreover,in vivo toxicity studies were performed on the nude mice for 15 days.The experimental animals in 10 or 15 mg/kg groups were similar with animals treated by phosphate buffer solution(PBS) after 15 days.The results of the multifa rious biochemical parameters also suggest that the functionalized products of CQDs do not influence the biological indicators at feasible concentration.Our findings in vitro and in vivo through toxicity tests demonstrate that CQDs and their modified materials are safe for future biological applications.     

Anticancer and microbicide action of carbon quantum dots derived from microcrystalline cellulose: Hydrothermal versus infrared assisted techniques

Urgent requirement for medication from cancer diseases and different microbial infections is interestingly considered. Carbon quantum dots (CQDs) as environmentally friendly fluorescent carbon nano-functionalized materials are popularly considered for application in medical purposes. Herein, a comparative study is presented for the affinity of CQDs ingrained from microcrystalline cellulose (MCC) prepared under hydrothermal conditions (CQDs-HT) versus that prepared under infrared assisted technique (CQDs-IR) for acting as anticancer and antimicrobial laborers. The estimated size averages for the obtained CQDs-HT & CQDs-IR were 7.8 & 9.8 nm, respectively. CQDs-HT showed rationally higher anti-proliferative action against Hepatocellular Carcinoma (HepG2) compared to CQDs-IR. Treatment with 1000 μg/mL of CQDs-IR & CQDs-HT exhibited 78 & 90 % mortality percentage of cancer cells, respectively. The obtained CQDs showed excellent microbicide potentiality and the minimum inhibitory concentration (MIC) from the synthesized CQDs-TH and CQDs-IR was ranged in 100–350 µg/mL and 300–400 µg/mL against different pathogens including bacteria and fungi, respectively. As a conclusion, hydrothermal technique showed seniority over infrared assisted technique in nucleation of CQDs with higher anticancer and microbicidal activities.     

Enhanced photocatalytic performance of carbon quantum dots/BiOBr composite and mechanism investigation

Novel CQDs/BiOBr composite photocatalysts are constructed via a simple hydrothermal synthesis and show superior activity in photocatalytic degradation of organic pollutants.     

碳点/β-环糊精复合物的制备及其用于尿酸检测的研究

以柠檬酸三钠为碳源,采用微波辅助制备碳点,用β-环糊精(β-CD)和碳点复合制备出碳点/β-CD复合物,并用荧光、紫外、红外光谱等进行表征.在pH=6.6的磷酸盐缓冲溶液中,尿酸可使碳点/β-CD复合物的荧光增强,探讨了反应时间、反应温度、缓冲溶液及pH对荧光增强程度的影响,建立了测定尿样中尿酸含量的方法.碳点/β-C...     

A Review on Carbon Quantum Dot Based Semiconductor Photocatalysts for the Abatement of Refractory Pollutants

Photocatalysis is a green approach frequently utilised to eliminate a variety of environmentally hazardous refractory pollutants. Accordingly, the modification of semiconductor photocatalysts with Carbon Quantum Dots (CQDs) is of great importance for the treatment of such pollutants due to their attractive physical and chemical properties. CQDs are a perfect candidate to handle photocatalysts of high-performance since they operate as co-catalysts and as visible light harvesters. The higher separation rate of electron-hole pairs in the photocatalytic system is attributable to better photodegradation efficiency. This review classifies CQD based photocatalysts as pure, doped and composite materials and discusses the specific advantages of CQDs in visible light-driven photocatalysis. In this work, the versatile roles of CQDs in CQD-based photocatalytic systems are thoroughly discussed and summarised.     

Room‐Temperature Solution‐Processed PbS Quantum Dot Solar Cells

Colloidal quantum dots (CQDs) are attractive absorber materials for high‐efficiency photovoltaics because of their facile solution processing, bandgap tunability due to quantum confinement effect, and multi‐exciton generation. To date, all published performance records for PbS CQDs solar cells have been based on the conventional hot‐injection synthesis method. This method usually requires relatively strict conditions such as high temperature and the utility of expensive source material (pyrophoric bis(trimethylsilyl) sulfide (TMS‐S)), limiting the potential for large‐scale and low‐cost synthesis of PbS CQDs. Here we report a facile room‐temperature synthetic method to produce high‐quality PbS CQDs through inexpensive ionic source materials including Pb(NO₃)₂ and Na₂S in the presence of triethanolamine (TEA) as the stabilizing ligand. The PbS CQDs were successfully prepared with an average particle size of about 5 nm. Solar cells based on the as‐synthesized PbS CQDs show a preliminary power conversion efficiency of 1.82%. This room‐temperature and low‐cost synthesis of PbS CQDs will further benefit the development of solution‐processed CQD solar cells.     

Electrochemistry in Carbon‐based Quantum Dots

Electrochemistry belongs to an important branch of chemistry that deals with the chemical changes produced by electricity and the production of electricity by chemical changes. Therefore, it can not only act a powerful tool for materials synthesis, but also offer an effective platform for sensing and catalysis. As extraordinary zero‐dimensional materials, carbon‐based quantum dots (CQDs) have been attracting tremendous attention due to their excellent properties such as good chemical stability, environmental friendliness, nontoxicity and abundant resources. Compared with the traditional methods for the preparation of CQDs, electrochemical (EC) methods offer advantages of simple instrumentation, mild reaction conditions, low cost and mass production. In return, CQDs could provide cost‐effective, environmentally friendly, biocompatible, stable and easily‐functionalizable probes, modifiers and catalysts for EC sensing. However, no specific review has been presented to systematically summarize both aspects until now. In this review, the EC preparation methods of CQDs are critically discussed focusing on CQDs. We further emphasize the applications of CQDs in EC sensors, electrocatalysis, biofuel cells and EC flexible devices. This review will further the experimental and theoretical understanding of the challenges and future prospective in this field, open new directions on exploring new advanced CQDs in EC to meet the high demands in diverse applications.     

Green process of biomass waste derived fluorescent carbon quantum dots for biological imaging in vitro and in vivo

In the context of the circular economy, the huge amounts of biomass waste should be converted into value-added materials and energy to diminish pollution, atmospheric CO₂ levels and costly waste disposal. Biological imaging usually uses expensive and toxic chemicals e.g., organic dyes, semiconductor quantum dots, calling for safer, greener, cheaper fluorescent probes for biological imaging in vitro and in vivo. In these regards, carbon quantum dots (CQDs)-based fluorescent probes using biomass waste as a precursor may have much higher potential. Here we transformed the biomass waste of peach leaves into value-added fluorescent CQDs through a low-cost and green one-step hydrothermal process. The obtained CQDs show excitation-dependent photoluminescence properties with a fluorescence lifetime of 5.96 ns and a quantum yield of 7.71% without any passivation. In addition, the CQDs have a fine size of 1.9 nm with good hydrophilicity and high fluorescent stability over pH 4.0–11.0 range. Fluorescence imaging of in vitro cell cultures and in vivo with zebrafish show that CQDs possess ultra-low toxicity and remarkable performance for biological imaging. Even when CQDs present at a concentration as high as 500 µg/mL, the organism can still maintain more than 90% activity both in vitro and in vivo, and present bright fluorescence. The cheaper, greener, ultra-low toxicity CQDs developed in this work is a potential candidate for biological imaging in vitro and in vivo.