Vedernikova, Anna A

Margaryan I.V., Vedernikova A.A., Borodina L., Kuzmenko N.K., Koroleva A.A., Zhizhin E.V., Zhang X., Ushakova E.V., Litvin A., Zheng W.

Abstract Solution-processed perovskite solar cells (PSCs) have demonstrated a tremendous growth in power conversion efficiency (PCE). A high-quality, defect-free perovskite-based active layer is a key point to enhance PSC performance. Introduction of additives and interlayers have proved to be an effective tool to passivate surface defects, control crystal growth, and improve PSC stability. Antisolvent engineering has emerged recently as a new approach, which aims to adjust perovskite layer properties and enhance the PCE and stability of PSC devices. Here, we demonstrate that carbon dots (CDs) may serve as a prospective additive for antisolvent engineering. Nitrogen-rich amphiphilic carbon dots were synthesized from amines by a solvothermal method and used as an additive to chlorobenzene for a perovskite layer fabrication. The interaction between perovskite and functional groups in CDs promotes improved crystallization of an active perovskite layer and defects passivation, bringing higher PSCs efficiency, stability, and suppressed hysteresis. Under optimized CD concentration, the maximum power conversion efficiency increased by 34 % due to the improved short-circuit current and fill factor, and the device maintains 87 % of its initial efficiency after 6 days of storage under ambient conditions.

Stepanidenko E.A., Vedernikova A.A., Mitroshin A.M., Arefina I.A., Parfenov P.S., Cherevkov S.A., Ushakova E.V.

Subject of study. The study focuses on luminescent carbon nanoparticles, specifically carbon dots, based on citric acid, formamide, and various chiral molecules. Aim of study. The aim is to assess the influence of chiral molecules used in the synthesis of carbon dots on optical transitions in the long-wavelength spectral region and to investigate the mechanism underlying the circular dichroism signal of these nanoparticles. Method. Carbon dot samples were synthesized using two methods: (i) a one-step solvothermal synthesis of carbon dots from citric acid, formamide, and various chiral molecules and (ii) a two-step method involving the solvothermal synthesis of achiral carbon dots from citric acid and formamide, followed by surface treatment with L-cysteine. Absorption and luminescence spectroscopy methods were employed to study the chemical structure and optical properties of the carbon dots. The chiroptical properties of the obtained samples were analyzed using circular dichroism spectroscopy. Main results. The addition of various chiral molecules to a mixture of precursors during one-step synthesis enabled the fabrication of carbon dots with different chemical compositions, including variations in surface groups and types of emission centers in the spectral region of 350–700 nm. The use of L-phenylglycine and L-tryptophan in the one-step synthesis was shown to lead to the formation of nanoparticles with optical transitions in both short- and long-wavelength regions of the spectrum. The addition of L-glutathione during the one-step synthesis resulted in the formation of carbon dots with short-wavelength emission, while the addition of L-cysteine did not alter the emission characteristics of achiral carbon dots based on citric acid and formamide. The optical properties of the chiral carbon dots obtained using the two-step synthesis method with L-cysteine remained unchanged compared with those of the achiral carbon dots synthesized from citric acid and formamide. The circular dichroism spectra of all the samples showed a signal at ∼250nm, which was attributed to the derivatives of the chiral precursors attached to the surface of the nanoparticles, irrespective of the preparation method. Practical significance. Chiral carbon dots hold promise in biomedicine as sensors, luminescent biomarkers, and other applications due to their biocompatibility and non-toxicity. The results obtained in this work will serve as a foundation for the further fabrication and investigation of chiral carbon nanoparticles with long-wavelength luminescence.

Stepanidenko E.A., Vedernikova A.A., Ondar S.O., Badrieva Z.F., Brui E.A., Miruschenko M.D., Volina O.V., Koroleva A.V., Zhizhin E.V., Ushakova E.V.

In this work, copper-doped carbon nanoparticles with emission in a wide spectral range and the ability to change the relaxation times of water protons during magnetic resonance imaging were fabricated. A high relaxivity value r1 = 0.92 mM–1 s–1 was achieved, which is the highest value of r1 for copper nanoparticles, to our knowledge. The suggested carbon nanoparticles are promising two-modal nanoprobes for bioimaging.

Tuchin V.S., Stepanidenko E.A., Vedernikova A.A., Cherevkov S.A., Li D., Li L., Döring A., Otyepka M., Ushakova E.V., Rogach A.L.

AbstractFunctional nanostructures build up a basis for the future materials and devices, providing a wide variety of functionalities, a possibility of designing bio‐compatible nanoprobes, etc. However, development of new nanostructured materials via trial‐and‐error approach is obviously limited by laborious efforts on their syntheses, and the cost of materials and manpower. This is one of the reasons for an increasing interest in design and development of novel materials with required properties assisted by machine learning approaches. Here, the dataset on synthetic parameters and optical properties of one important class of light‐emitting nanomaterials – carbon dots are collected, processed, and analyzed with optical transitions in the red and near‐infrared spectral ranges. A model for prediction of spectral characteristics of these carbon dots based on multiple linear regression is established and verified by comparison of the predicted and experimentally observed optical properties of carbon dots synthesized in three different laboratories. Based on the analysis, the open‐source code is provided to be used by researchers for the prediction of optical properties of carbon dots and their synthetic procedures.

Vedernikova A.A., Miruschenko M.D., Arefina I.A., Xie J., Huang H., Koroleva A.V., Zhizhin E.V., Cherevkov S.A., Timin A.S., Mitusova K.A., Shipilovskikh S.A., Ushakova E.V.

Stepanidenko E.A., Vedernikova A.A., Miruschenko M.D., Dadadzhanov D.R., Feferman D., Zhang B., Qu S., Ushakova E.V.

Stepanidenko E.A., Vedernikova A.A., Badrieva Z.F., Brui E.A., Ondar S.O., Miruschenko M.D., Volina O.V., Koroleva A.V., Zhizhin E.V., Ushakova E.V.

Luminescent carbon nanodots (CDs) are a low-toxic nanomaterial with a tunable emission in a wide spectral range and with various functional groups on the surface. Therefore, CDs can prospectively serve as luminescent nanoprobes for biomedical applications, such as drug-delivery, visualization, sensing, etc. The doping of CDs with paramagnetic or transition metals allows the expansion of the range of applications of CDs and the fabrication of a multimodal nanoprobe for bioimaging. Here, we developed CDs doped with manganese (Mn) based on commonly used precursors—o-phenylenediamine or citric acid and formamide. The chemical structure, morphology, optical properties, and magnetic resonance responses have been carefully studied. The obtained CDs are up to 10 nm, with emissions observed in the 400–650 nm spectral region. CDs exhibit an ability to reduce both T1 and T2 relaxation times by up to 6.4% and 42.3%, respectively. The high relaxivity values suggest the use of CDs as promising dual-mode contrast agents for T1 and T2 MRI. Therefore, our developed CDs can be utilized as a new multifunctional nanoscale probe for photoluminescent and magnetic resonance bioimaging.

Margaryan I.V., Vedernikova A.A., Parfenov P.S., Baranov M.A., Danilov D.V., Koroleva A.V., Zhizhin E.V., Cherevkov S.A., Zhang X., Ushakova E.V., Litvin A.P.

Photovoltaic devices based on organic–inorganic hybrid perovskites have engaged tremendous attention due to the enormous increase in power conversion efficiency (PCE). However, defect states formed at grain boundaries and interfaces hinder the achievement of PCE. A prospective strategy to both reduce interfacial defects and control perovskite growth is the passivation of interfaces. The passivation of the electron-transporting layer/perovskite interface with ultrasmall carbon dots (CDs) with suitable chemical composition and functional groups on their surface may simultaneously affect the morphology of a perovskite layer, facilitate charge carriers extraction, and suppress interfacial recombination. Here, we show that CDs synthesized from diamine precursors may be used as an interlayer at the SnO2/FACsPbI3 interface. Ultrasmall CDs form a smooth, thin layer, providing better perovskite layer morphology. CD interlayers result in an increased average perovskite grain size, suppress the formation of small grains, and improve charge carriers’ extraction. As a result, photovoltaic devices with CD interlayers demonstrate a higher PCE due to the increased short-circuit current density and fill factor. These findings provide further insight into the construction of interfaces based on carbon nanomaterials.

Arefina I.A., Kurshanov D.A., Vedernikova A.A., Danilov D.V., Koroleva A.V., Zhizhin E.V., Sergeev A.A., Fedorov A.V., Ushakova E.V., Rogach A.L.

Carbon dots can be used for the fabrication of colloidal multi-purpose complexes for sensing and bio-visualization due to their easy and scalable synthesis, control of their spectral responses over a wide spectral range, and possibility of surface functionalization to meet the application task. Here, we developed a chemical protocol of colloidal complex formation via covalent bonding between carbon dots and plasmonic metal nanoparticles in order to influence and improve their fluorescence. We demonstrate how interactions between carbon dots and metal nanoparticles in the formed complexes, and thus their optical responses, depend on the type of bonds between particles, the architecture of the complexes, and the degree of overlapping of absorption and emission of carbon dots with the plasmon resonance of metals. For the most optimized architecture, emission enhancement reaching up to 5.4- and 4.9-fold for complexes with silver and gold nanoparticles has been achieved, respectively. Our study expands the toolkit of functional materials based on carbon dots for applications in photonics and biomedicine to photonics.

Vedernikova A.A., Miruschenko M.D., Arefina I.A., Babaev A.A., Stepanidenko E.A., Cherevkov S.A., Spiridonov I.G., Danilov D.V., Koroleva A.V., Zhizhin E.V., Ushakova E.V.

Today, the development of nanomaterials with sensing properties attracts much scientific interest because of the demand for low-cost nontoxic colloidal nanoprobes with high sensitivity and selectivity for various biomedical and environment-related applications. Carbon dots (CDs) are promising candidates for these applications as they demonstrate unique optical properties with intense emissions, biocompatibility, and ease of fabrication. Herein, we developed synthesis protocols to obtain CDs based on o-phenylenediamine with a variety of optical responses depending on additional precursors and changes in the reaction media. The obtained CDs are N-doped (N,S-doped in case of thiourea addition) less than 10 nm spherical particles with emissions observed in the 300–600 nm spectral region depending on their chemical composition. These CDs may act simultaneously as absorptive/fluorescent sensing probes for solvent polarity with ∆S/∆ENT  up to 85, for ∆ENT from 0.099 to 1.0 and for pH values in the range of 3.0–8.0, thus opening an opportunity to check the pH in non-pure water or a mixture of solvents. Moreover, CDs preserve their optical properties when embedded in cellulose strips that can be used as sensing probes for fast and easy pH checks. We believe that the resulting dual-purpose sensing nano probes based on CDs will have high demand in various sensing applications.

Ушакова Е.В., Баранов А.В., Федоров А.В., Ведерникова А.А., Арефина И.А.

In recent years, carbon dots have attracted much scientific attention due to their unique properties, which can find applications in many fields. We have developed synthesis protocols of carbon dots with different structure and optical properties using o-phenylenediamine. The change in absorption and luminescence spectra of carbon dots were studied in detail. The obtained samples show intensive luminescence at 350 nm and 450 or 550 nm dependent on synthesis parameters.

Das A., Kundelev E.V., Vedernikova A.A., Cherevkov S.A., Danilov D.V., Koroleva A.V., Zhizhin E.V., Tsypkin A.N., Litvin A.P., Baranov A.V., Fedorov A.V., Ushakova E.V., Rogach A.L.

AbstractCarbon dots (CDs) are light-emitting nanoparticles that show great promise for applications in biology and medicine due to the ease of fabrication, biocompatibility, and attractive optical properties. Optical chirality, on the other hand, is an intrinsic feature inherent in many objects in nature, and it can play an important role in the formation of artificial complexes based on CDs that are implemented for enantiomer recognition, site-specific bonding, etc. We employed a one-step hydrothermal synthesis to produce chiral CDs from the commonly used precursors citric acid and ethylenediamine together with a set of different chiral precursors, namely, L-isomers of cysteine, glutathione, phenylglycine, and tryptophan. The resulting CDs consisted of O,N-doped (and also S-doped, in some cases) carbonized cores with surfaces rich in amide and hydroxyl groups; they exhibited high photoluminescence quantum yields reaching 57%, chiral optical signals in the UV and visible spectral regions, and two-photon absorption. Chiral signals of CDs were rather complex and originated from a combination of the chiral precursors attached to the CD surface, hybridization of lower-energy levels of chiral chromophores formed within CDs, and intrinsic chirality of the CD cores. Using DFT analysis, we showed how incorporation of the chiral precursors at the optical centers induced a strong response in their circular dichroism spectra. The optical characteristics of these CDs, which can easily be dispersed in solvents of different polarities, remained stable during pH changes in the environment and after UV exposure for more than 400 min, which opens a wide range of bio-applications.

Chen M., Ma J., Feng Y., Wu Y., Hu G., Liu X.

Roy B., Maikap A., Das S., Chakraborty S.

Yang B., Zhang Z., Luo Y., Li X., Chang H.

Fang Z., Li X., Zhang X., Yan W., Liu J., Zhao L.

Pei H., Zhang Z., Ouyang M., Liang H., Liu J., Li S., Zhang H., Qi Y., Wei L., Liu C., Shi L., Guo R., Liu N., Mo Z.

Li D., Wang X., Wang S., Song X., Fang L., Zhang Y., Ba X., Wang S.

Zhang Y., Yang Y., Ding S., Zeng X., Li T., Hu Y., Lu S.

AbstractBiological lasers, representing innovative miniaturized laser technology, hold immense potential in the fields of biological imaging, detection, sensing, and medical treatment. However, the reported gain media for biological lasers encounter several challenges complex preparation procedures, high cost, toxicity concerns, limited biocompatibility, and stability issues along with poor processability and tunability. These drawbacks have impeded the sustainable development of biological lasers. Carbon dots (CDs), as a novel solution‐processable gain materials characterized by facile preparation, low cost, low toxicity, excellent biocompatibility, high stability, easy modification, and luminescence tuning capabilities along with outstanding luminescence performance. Consequently, they find extensive applications in diverse fields such as biology, sensing, photoelectricity, and lasers. Henceforth, they are particularly suitable for constructing biological lasers. This paper provides a comprehensive review on the classification and application of existing biological lasers while emphasizing the advantages of CDs compared to other gain media. Furthermore, it presents the latest progress made by utilizing CDs as gain media and forecasts both promising prospects and potential challenges for biological lasers based on CDs. This study aims to enhance understanding of CD lasers and foster advancements in the field of biological lasers.

Nikitin I.Y., Borodina L.N., Boltenko A.V., Baranov M.A., Gladskikh I.A., Vartanyan T.A.

Yan F., Bai R., Huang J., Bian X., Fu Y.

Chen J., Li T., Lin C., Hou Y., Cheng S., Gao B.

Miruschenko M.D., Kosolapova K.D., Aleinik I.A., Borodina L.N., Vedernikova A.A., Sokolova A.V., Sandzhieva M.A., Mitroshin A.M., Yakimansky A.V., Koroleva A.V., Zhizhin E.V., Cherevkov S.A., Langer M., Otyepka M., Ushakova E.V., et. al.

Carbon dots (CDs) are fluorescent carbon nanomaterials that are considered for applications in optoelectronics, sensorics, and biofields due to their low‐cost and robust synthesis, and versatile optical properties. Herein, it is demonstrated how chemical functionalization of hydrophilic or amphiphilic CDs with polyethylene glycol influences their energy level structure and hence the emission properties. Functionalization of CDs with polyethylene glycol results in an increase in emission quantum yield: from 30% to 75% for hydrophilic CDs and from 20% to 25% for amphiphilic CDs. The estimated absolute values of energy levels, including the highest occupied molecular orbital and the lowest unoccupied molecular orbital energies, are dependent on chemical composition and size of CDs. Moreover, polyethylene glycol‐functionalized CD can form good quality films based on their composite with polyvinylcarbazole (PVK), that together with intense emission is crucial for light‐emitting diode (LED) fabrication. By studying spectral properties of fabricated CD‐LEDs, it is shown that their electroluminescence (EL) originates from mixed energy levels of CD and PVK in the composite, resulting in the shifting of the EL maximum from blue to green during several seconds of LED operation. The optimized CD‐LEDs show brightness up to 2600 cd m−2.

Nandi N., Sarkar P., Barnwal N., Sahu K.

AbstractDiscovered only in 2004, carbon dots (CDs) have already traversed a long journey, generating many promising research directions. Its cheapness, ease of synthesis, high water‐solubility, tunable emission, and excellent biocompatibility make it a single‐point solution to many problems, and tremendous efforts were invested into understanding the structure‐property‐function relationship, which eases the engineering of the CD properties suitable for a desired application. From the usual random choice of precursors or carbon materials as a starting point in the early days, more systematic approaches are now available for choosing proper starting materials and appropriate experimental conditions (solvent medium, reaction temperature, reaction duration, pH, etc) to customize its photoluminescence. The presence of impurities has a crucial role in the outcome and applicability of photoluminescence. Recently, a significant focus has been on the long‐wavelength emissive CDs, particularly in the red to near‐infrared (NIR) regions, for better penetration into live cells and to circumvent autofluorescence problems. Proper design can harvest phosphorescence from CDs. Many excellent reviews are available, focusing on different facets of CD prospects. Hence, we will only highlight the importance of the optical properties of CDs and ways to modulate them. We will mention some of the new works that have appeared in the last five years.

Matyszczak G., Krawczyk K., Yedzikhanau A.

Nanomaterials, including quantum dots, have gained more and more attention in the past few decades due to their extraordinary properties that make them useful for many applications, ranging from catalysis, energy generation and storage, biotechnology, and medicine to quantum informatics. Mathematical descriptions of the phenomena in which nanostructures are involved are of great demand because they may be utilized for the purpose of controlling these phenomena (e.g., the growth of nanostructures with certain sizes, shapes, and other properties). Such models may be of distinct nature, including calculations from first principles, ordinary and partial differential equations, and machine learning models (including artificial intelligence) as well. The aim of this article is to review the most important and useful computational and mathematical approaches for the description and control of processes involving nanostructures.

Li Y., Liu Z., Ren H., Chen C.

The dyeing industry wastewater has greatly hampered the ecological environment. The carbon quantum dots (CQDs) is a promising catalyst for photocatalytic degradation. To control the specified structure of CQDs, a designable-green deep eutectic solvents (DESs) was targeted as the precursor. In this work, a copper-doped solid-state Cu-CQDs was successfully prepared by combustion method from glycerol/choline chloride/CuCl2·2H2O DESs, and characterized by Fourier transform infrared spectroscopy, XRD, XPS, UV–Vis spectroscopy, and fluorescence spectroscopy. The analysis revealed that the metallic copper-doped Cu-CQDs have better morphological and structural properties and exhibit good optics characteristics. The prepared CQDs were applied to the photocatalytic degradation of Rhodamine-B (RhB). It was found that the ⋅O2− was the main active specie, and it can efficient degrade RhB up to 95%.

Pandey A., Raikwar V., Awade D.

Carbon dots (CDs) are extensively utilized in biomedicine, optical devices, and sensing due to their low toxicity, excellent optical properties, and ease of synthesis. Nonetheless, there is ongoing discussion over the comprehensive investigation of CDs photoluminescence (PL) process because of their intricate architectures and surface functions. Carbon dots (CDs) and CD/PVP composites were one step synthesized in a hydrothermal process using citric acid and NaOH as precursors. Due to surface defects of CDs after incorporating into Polyvinylpyrrolidone (PVP) both shift in color as well as change in emission is observed. It shows the enhancement of the luminescence property of CDs/PVP and the application of CD/PVP composite in the field of optical emission. Further for practical application, emission of white light emitting diodes (WLEDs) was demonstrated by coating a 370 nm UV-LED with CD/PVP composite. The WLED shows significant CRI, good S/P ratio, the color gamut score Rg and color fidelity score Rf which are essential features for a good light source. Our research offers a valuable reference for CD/PVP composites in a facile, low temperature and low-cost hydrothermal process and developing WLED with UV-LED and metal free phosphors.

He J., Mu Y., Wu B., Wu F., Liao R., Li H., Zhao T., Zeng L.

Zinc-iodine batteries are considered promising energy storage devices due to the non-flammable aqueous electrolyte and intrinsically safe zinc. However, the polyiodide shuttle effect and sluggish reaction kinetics limit their electrochemical...

Yin X., Wei S., Zhai C., Wang B., Zhang H., Wang C., Song X., Sun G., Jiang C.

Potassium ferricyanide (K4[Fe(CN)6]) as anti-caking agent plays an important role in avoiding the formation of chunks for fine particulate solids. However, inappropriate and excessive addition and decomposition of K4[Fe(CN)6] are detrimental to physical health. At present, appropriate strategies for convenient and accurate analysis of K4[Fe(CN)6] in table salt and pickled food are desirable. Herein, an efficient “ON-OFF-ON” fluorescent sensor based on chiral carbon dots was prepared by a simple one-step hydrothermal method. The chiral CDs with l-Tryptophan and d-Tryptophan as chiral source were named as l-CDs and d-CDs. Notably, the bright fluorescence of L/d-CDs could be effectively quenched by K4[Fe(CN)6] through dynamic quenching mechanism. This fluorescent sensor achieved excellent sensitive and selective detection of K4[Fe(CN)6] with a limit of detection (LOD) of 25.0 ng·mL−1. In addition, the L/d-CDs could be applied not only for selective fluorescent recognition of K4[Fe(CN)6] by the methods of portable filter paper and hydrogels, but also as fluorescent dye for repeated message encryption and decryption.

Vedernikova A.A., Miruschenko M.D., Arefina I.A., Xie J., Huang H., Koroleva A.V., Zhizhin E.V., Cherevkov S.A., Timin A.S., Mitusova K.A., Shipilovskikh S.A., Ushakova E.V.

Stepanidenko E.A., Vedernikova A.A., Miruschenko M.D., Dadadzhanov D.R., Feferman D., Zhang B., Qu S., Ushakova E.V.

Luo Z., Zhang X., Wang C., Zhang W., Zheng W.

Lead halide perovskite solar cells can be significantly improved with multifunctional additives such as carbon dots (CDs) with amine terminals via defect passivation and band alignment. Here, we determine rational guidelines for the usage of such quantum dots in perovskite solar cells by systematically studying their effects on crystal quality and carrier transport. The amine-terminated CDs homogeneously dispersed in precursors improve the crystal quality of perovskite films, but they reduce the hole mobility hampering hole extraction. In contrast, CDs deposited between the electron transport layer and active layer could promote spin-coated film quality and electron’s extraction efficiently. So, the approaches of the carbon dots in device alters semiconductor properties and energy level structure. Interface engineering achieve better crystal quality and energy level alignment, which in turn affects charge collection, thereby increasing current density and power conversion efficiency. According to the findings of this study, when considering defect passivation by additives, the energy band alignment of the device should also be considered, since this could change carrier dynamics and device performance differently.

Tang Y., Xu Q., Zhu P., Zhu R., Wang J.

This review introduces machine learning into imaging, sensing, and cancer therapy for CDs, demonstrating the great potential for ML to accelerate developments in materials science and provide new insight into the biological application field.

Ma G., Ye J., Qin M., Sun T., Tan W., Fan Z., Huang L., Xin X.

Active bifunctional electrocatalysts that can catalyze both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are highly desirable for overall water splitting. One such catalyst, NiCoP, demonstrates potential due to its unique electronic and structural properties that allow for efficient charge transfer between the catalyst and reactants. However, its OER performance is often unsatisfactory compared to its high HER performance. To address this problem, we prepared Mn-doped nickel cobalt phosphide (Mn-NiCoP) with nanopins arrays by in situ growth on nickel foam (NF), which only requires the overpotentials of 148 mV for HER and 266 mV for OER at a high current density of 100 mA cm−2. Consequently, the achieved water splitting performance with Mn-NiCoP as both anode and cathode at a high current density of 100 mA cm−2 were as low as 1.69 V, and its maintenance was 94% after 240 hours. Furthermore, we demonstrate that the simultaneous improvement of both the OER and HER performances on Mn-NiCoP is due to the synergistic effect of the preferred moderate amount of Mn doping and Co alloying, through first-principles calculations of electronic structures, electrochemical stabilities, and reaction chemical potentials for different surface adsorption states. Overall, this work provides inspiration for optimizing the OER performance of traditional HER catalysts, thereby promoting overall water splitting using only one catalyst in the same solution.

Chen X., Yu M., Li P., Xu C., Zhang S., Wang Y., Xing X.

Wang J., Fu Y., Gu Z., Pan H., Zhou P., Gan Q., Yuan Y., Liu C.

AbstractDesigning suitable nanomaterials is an ideal strategy to enable early diagnosis and effective treatment of diseases. Carbon dots (CDs) are luminescent carbonaceous nanoparticles that have attracted considerable attention. Through facile synthesis, they process properties including tunable light emission, low toxicity, and light energy transformation, leading to diverse applications as optically functional materials in biomedical fields. Recently, their potentials have been further explored, such as enzyme‐like activity and ability to promote osteogenic differentiation. Through refined synthesizing strategies carbon dots, a rich treasure trove for new discoveries, stand a chance to guide significant development in biomedical applications. In this review, the authors start with a brief introduction to CDs. By presenting mechanisms and examples, the authors focus on how they can be used in diagnosing and treating diseases, including bioimaging failure of tissues and cells, biosensing various pathogenic factors and biomarkers, tissue defect repair, anti‐inflammation, antibacterial and antiviral, and novel oncology treatment. The introduction of the application of integrated diagnosis and treatment follows closely behind. Furthermore, the challenges and future directions of CDs are discussed. The authors hope this review will provide critical perspectives to inspire new discoveries on CDs and prompt their advances in biomedical applications.

Shi Y., Su W., Teng Q., Li C., Yuan T., Xu H., Song X., Han Y., Wei S., Zhang Y., Li X., Li Y., Fan L., Yuan F.

Carbon dots (CDs), with the unique advantages of low cost, low toxicity, good photostability, and tunable photoluminescence, have achieved remarkable progress in terms of their controllable synthesis and application in the fields of optoelectronics and biomedicine. However, as an emerging type of chiral nanomaterial, chiral CDs (CCDs) are still at a primary research stage. In this review, we systematically summarize the recent developments in CCDs ranging from their chemical synthesis to the related structural engineering and their optical properties. Moreover, we highlight the recent progress regarding the use of CCDs in technological and biological applications. Finally, we conclude with a discussion regarding the current challenges and future research on the development of CCDs. We hope that this review will inspire more exciting research on CCDs from a new perspective and promote the practical applications of CCDs in multiple current and future research directions.

He H., E S., Ai L., Wang X., Yao J., He C., Cheng B.

Benefitting from their prominent corrosion inhibition properties, excellent water solubility and benign environmental friendliness, carbon dots (CDs) have functioned as an ideal candidate for next-generation green corrosion inhibitors. However, the extensive adoption of the trial-and-error route driven by artificial experience in the preparation of CDs-based corrosion inhibitors leads to resource waste and environmental implications, detrimental to their sustainable development. It is still a considerable challenge to controllably prepare CDs-based corrosion inhibitors with the predictable inhibition efficiency. Herein, firstly exploiting a data-driven machine learning (ML) approach, this study aims to precisely predict the inhibition efficiency of CDs and optimize their synthesis route, resulting in the controlled synthesis of CDs-based corrosion inhibitors. Specifically, the dataset is constructed by combining 102 data points on CDs synthesis and inhibition efficiency from numerous published studies and our own experiments. After training and evaluation of different ML models, the Random Forest (RF) ML regression model is chosen with the lowest root-mean-square error and mean absolute error as well as the highest coefficient of determination. The results show that this RF model can comprehensively reveal the relationship between various hydrothermal synthesis parameters and the inhibition efficiency. Guided by the RF model, the inhibition efficiencies of CDs-based corrosion inhibitors are accurately predicted with an error less than 10%, and based on the genetic algorithm, their synthesis route is intelligently optimized. This work demonstrates the feasibility of ML techniques in guiding the optimization of synthesis conditions for CDs-based corrosion inhibitors. This optimization process results in reduced development time and cost, contributing to the sustainability and cleaner production of inhibitors.

Choubisa H., Haque M.A., Zhu T., Zeng L., Vafaie M., Baran D., Sargent E.H.

AbstractThe exploration of thermoelectric materials is challenging considering the large materials space, combined with added exponential degrees of freedom coming from doping and the diversity of synthetic pathways. Here, historical data is incorporated, and is updated using experimental feedback by employing error‐correction learning (ECL). This is achieved by learning from prior datasets and then adapting the model to differences in synthesis and characterization that are otherwise difficult to parameterize. This strategy is thus applied to discovering thermoelectric materials, where synthesis is prioritized at temperatures <300 ○C. A previously unexplored chemical family of thermoelectric materials, PbSe:SnSb, is documented, finding that the best candidate in this chemical family, 2 wt% SnSb doped PbSe, exhibits a power factor more than 2× that of PbSe. The investigations herein reveal that a closed‐loop experimentation strategy reduces the required number of experiments to find an optimized material by a factor as high as 3× compared to high‐throughput searches powered by state‐of‐the‐art machine‐learning (ML) models. It is also observed that this improvement is dependent on the accuracy of the ML model in a manner that exhibits diminishing returns: once a certain accuracy is reached, factors that are instead associated with experimental pathways begin to dominate trends.

Shi Y., Su W., Yuan F., Yuan T., Song X., Han Y., Wei S., Zhang Y., Li Y., Li X., Fan L.

AbstractCarbon dots (CDs), as emerging carbon nanomaterials, have been regarded as promising alternatives for electroluminescent light‐emitting diodes (LEDs) owing to their distinct characteristics, such as low toxicity, tuneable photoluminescence, and good photostability. In the last few years, despite remarkable progress achieved in CD‐based LEDs, their device performance is still inferior to that of well‐developed organic, heavy‐metal‐based QDs, and perovskite LEDs. To better exploit LED applications and boost device performance, in this review, a comprehensive overview of currently explored CDs is presented, focusing on their key optical characteristics, which are closely related to the structural design of CDs from their carbon core to surface modifications, and to macroscopic structural engineering, including the embedding of CDs in the matrix or spatial arrangement of CDs. The design of CD‐based LEDs for display and lighting applications based on the fluorescence, phosphorescence, and delayed fluorescence emission of CDs is also highlighted. Finally, it is concluded with a discussion regarding the key challenges and plausible prospects in this field. It is hoped that this review inspires more extensive research on CDs from a new perspective and promotes practical applications of CD‐based LEDs in multiple directions of current and future research.

Xing C., Chen G., Zhu X., An J., Bao J., Wang X., Zhou X., Du X., Xu X.

Carbon dots (CDs) have wide application potentials in optoelectronic devices, biology, medicine, chemical sensors, and quantum techniques due to their excellent fluorescent properties. However, synthesis of CDs with controllable spectrum is challenging because of the diversity of the CD components and structures. In this report, machine learning (ML) algorithms were applied to help the synthesis of CDs with predictable photoluminescence (PL) under the excitation wavelengths of 365 and 532 nm. The combination of precursors was used as the variable. The PL peaks of the strongest intensity (λs) and the longest wavelength (λl) were used as target functions. Among six investigated ML models, the random forest (RF) model showed outstanding performance in the prediction of the PL peaks.

Gao P., Li C., Zhang N.

X-ray photoelectron spectroscopy is a powerful tool to identify the interaction between additives or surface treatments with components in lead halide perovskites. However, with the increasing number of studies using...