In this paper, the most recent advances in graphene lithium-ion batteries were summarized. Graphene-based anode and cathode materials for lithium-ion batteries were described in details, and the prospect of graphene lithium-ion batteries was also discussed.
The layered structure of transition metal dichalcogenides (TMDs) gives rise to many novel properties for functional applications in a wide range of fields. However, successful synthesis of TMDs and directly modulating properties of TMDs during the growth process are facing great challenges, which limits their future practical applications. In this review, we focus on current state of the art chemical vapor deposition (CVD) synthesis of TMDs alloys, convenient methods to modulate properties of TMDs by CVD. Then, TMDs-based lateral and vertical heterostructures utilizing CVD methods are reviewed. Finally, we summarize patterned growth of TMDs briefly.
In vivo biological imaging in first near-infrared window (NIR-I, 700-900 nm) and the second near-infrared window (NIR-II, 1000-1700 nm) using conjugated polymers have recently attracted great interest. Compared with imaging in visible region (400-700 nm), NIR bioimaging can provide deeper tissue penetration and higher spatial resolution due to fewer scattering of longer-wavelength photons. Moreover, most of NIR-I and NIR-II conjugated copolymers have been reported with tunable excitation and emission of fluorophores through modification of their donor-acceptor structures. In this minireview, we focus on the recent advances on chemical synthesis of conjugated polymers and their biological imaging in NIR-I and NIR-II windows.
A photocatalytic composite of β-cyclodextrin/titanium dioxide (β-CD/TiO2) was synthesized via the photoinduced assembly method in this work. The morphology of the composite was characterized by scanning electron microscope (SEM) and transmission electron microscopy (TEM), respectively. The chemical composition was detected by fourier transform infrared spectroscopy (FTIR). By means of phenolphthalein probe technique and back titration method, the contents of active β-CD (2.0%) and TiO2 (0.0971±0.0006 g/0.1 g) in the prepared β-CD/TiO2 composite were obtained. In order to investigate deeply the role of β-CD in TiO2 photocatalytic system, 100 mL of 0.1 mmol L-1 methyl orange (MO) aqueous solution was used as the organic pollutant, the photocatalytic activity of β-CD/TiO2 and pure TiO2 were assessed under the same conditions. The results showed that the degradation time of β-CD/TiO2 was 43% shorter than that degraded by the aqueous solution containing only TiO2. β-CD/TiO2 demonstrated a better photocatalytic activity. The kinetics of photocatalytic degradation of MO by β-CD/TiO2 and pure TiO2 was studied. In addition, the degradation efficiency of MO by β-CD/TiO2 was still above 85% after recycling for 5 times.
Iron oxides, such as hematite (α-Fe2O3), maghemite (γ-Fe2O3), and magnetite (Fe3O4), have been considered as alternative anode materials for lithium-ion batteries (LIBs) due to their high theoretical capacity, abundant reserves, low cost, and non-toxicity. However, their practical application has been hampered by the large volume expansion, which leads to rapid capacity fading. Nanostructure engineering has been demonstrated to be an effective avenue in tackling the volume variation issue and boosting the electrochemical performances. Herein, recent advances on nanostructure engineering of iron oxides for lithium storage are summarized. These nanostructures include 0D nanoparticles, 1D nanowires/nanorods/ nanofibers/nanotubes, 2D nanoflakes/nanosheets, as well as 3D porous/hollow/hierarchical architectures. The structure- electrochemical performance correlations are also discussed. It is believed that the performance optimization strategies summarized here might be extended to other high-capacity LIB anode materials.
Removal of mercury contaminants from nature receives a global attention from a biological and environmental standpoint. Recently, metal-organic frameworks (MOFs) show much promises in the adsorptive removal of mercury species. This review summarizes the recent studies on the MOF-based materials for mercury sensing and removal. The design of those materials are listed in five categories—use of unfunctionalized MOFs, linker design of MOFs, modification of MOF system, post-synthetic modification of the frameworks, and development of MOF-based composites. Finally, several key learning points are discussed in the aim of a facilitating new design of MOF-based sensors and adsorbents for mercury.
NiCo2S4 has attracted worldwide attention in the field of energy storage/conversion. In this paper, we summarize the up-to-date progress on the preparation strategies, the applications as electrode materials for supercapacitors, lithium-ion batteries and dye sensitized solar cells, as well as electrocatalysts for the hydrogen evolution reaction, oxygen reduction reaction and oxygen evolution reaction. We also discuss the strategies to improve the electrochemical performance, and future trends of the NiCo2S4-based materials.
Highly efficient blue phosphorescent organic light-emitting diode (OLED) is achieved by using a blend of biphenyl (spiro[fluorene-9,9'-xanthen]-2-yl) phosphine oxide (SFX2PO) and various of hole- or electron-transporting materials such as di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane (TAPC), 2,2',2"-(1,3,5-benzinetriyl)-tris(1- phenyl-1-H-benzimidazole) (TPBi) and 4,4',4"-tris(carbazol-9-yl)triphenylamine (TCTA). The results show that TCTA and SFX2PO can partially form exciplex and have better charge carrier balance performance. The driving voltage and efficiency are improved in a multi-player device with TCTA and SFX2PO as the co-host. The device shows a maximum current efficiency of 22.75 cd•A–1, which is nearly two folds over the device using SFX2PO or phosphine oxide spirobifluorene derivative (SPPO1) as a single host.
Organic electrode materials offer virtually infinite resource availability, cost advantages, and some of the highest specific energy for batteries to satisfy the demand for large-scale energy storage. Among the biggest challenges for the practical applications of batteries based on organic electrodes is the dissolution of organic active materials into the electrolyte, which leads to underwhelming cycling stability. This minireview provides an overview of electrolyte advancements to improve the stability of organic batteries. Research efforts on the control of solvent polarity, electrolyte mobility, and exploration of novel electrolyte systems are highlighted.
The aim of this study was to investigate the effect of incorporation of the nano silica modified with (3-aminopropyl)triethoxysilane (APTES@SiO2) on the degree of conversion, bond strength and biocompatibility of an experimental dental adhesive. An amphiphilic bonding system was used as the experimental dentin bonding system. The APTES@SiO2 with diameter of 70 nm was prepared and added into the experimental dentin bonding system as nanofiller, and the effect of the modification on the stability of the nano APTES@SiO2 dispersed in the experimental adhesive was studied. In addition, the morphology, degree of conversion, bond strength to dental restorative resin and biocompatibility of the experimental adhesives containing nanofiller were tested. After modification, the dispersion stability of the nano particles in the adhesive was improved. With increasing the content of the nano APTES@SiO2, the rate of light conversion increased significantly. However, the ultimate degree of conversion, bond strength to resin and bulk compressive strength was not significantly affected. Compared with the adhesive without nanofiller, the adhesive with 2 wt% APTES@SiO2 showed better bond strength to dentin and lower polymerization shrinkage. In addition, the experimental adhesive showed slight cytotoxicity with the incorporation of APTES@SiO2, but it was attenuated at low concentration.
As an inorganic sunscreen material, nano-titanium dioxide (nano-TiO2) owns broad prospects in sunscreen cosmetics for its small size, non-toxicity, strong covering ability, UV absorption and scattering abilities, etc. Nano-TiO2 has high photocatalytic activity, so it will go through a series of complex chemical reactions under light irradiation and cause damage to its surrounding agents. In addition, it is hard to disperse in various aqueous and non-aqueous mediums due to its high surface energy and hydrophobic property. In order to apply nano-TiO2 to cosmetics effectively and safely, its surface modification is necessary. This paper reviews nano-TiO2’s preparation, modification, and its application in sunscreen cosmetics.
Photocatalytic degradation of organic pollutants is an effective way to overcome environmental pollution. During the past few years, carbon materials have demonstrated great potential to improve photocatalytic performance of ZnO nanomaterials. This review will comment on recent developments of carbon materials (including fullerene, carbon nanotube, and graphene) coupling to improve photocatalytic performance of ZnO for photodegradatation of organic pollutants. The effects of carbon materials on enhancing photocatalytic performance of ZnO include enhancing structure stability, increasing amounts of active sites of pollutant adsorption, boosting electron acceptor formation and transport, enhancing photosensitization, narrowing band gap, etc. Moreover, basic mechanisms how carbon materials enhance photocatalytic activity of ZnO materials are discussed according to the interaction between ZnO and carbon materials. Finally, concluding remarks and current challenges are highlighted with perspectives for future developments of ZnO-based carbon photocatalysts. This review aims at recent research advances on ZnO-based carbon photocatalysts developed for photocatalysis of organic contaminant degradation.
Perfluorotripropylamine (FC-3283), a kind of perfluorocarbon as oxygen carrier, is encapsulated in a copolymer using polyethylene glycol (PEG) to modify poly lactic-co-glycolic acid (PLGA) to prepare a PLGA-PEG/FC-3283 emulsion for highly efficient reoxygenation to cell. 1H nuclear magnetic resonance (1H NMR) spectra, Fourier transform infrared spectrum (FT-IR), transmission electron microscopy (TEM), dynamic light scattering (DLS) and high performance ion chromatography proved the formation of the PLGA-PEG and PLGA-PEG/FC-3283 emulsion. High performance ion chromatography revealed that FC-3283 content in the emulsion is 9.4%. Furthermore, CCK-8 assay was used to detect the cytotoxicity of the PLGA-PEG/FC-3283 emulsion to HCT 116 cells. Finally, the ability of oxygen supply and release of PLGA-PEG/FC-3283 emulsion was evaluated by CCK-8 asssy and fluorophotometry based on establishing hypoxia/reoxygenation model of HCT 116 cells with liquid paraffin. By detecting the cells increment rate and the content changes of reactive oxygen species (ROS) before and after reoxygenation, we explored the oxygen carry and release ability of PLGA-PEG/FC-3283 emulsion. The results showed that the cell viability increased significantly through PLGA-PEG/FC-3283 emulsion administration after the cells were treated with hypoxia.
Cancer is one of the leading causes of death worldwide, so early cancer diagnosis is of great significance for successful treatment of cancer. This paper reviews some advances on graphene-based electrochemical biosensors for early cancer diagnosis including electrochemical immunosensors, electrochemical DNA biosensors, and electrochemical cell biosensors.
The structural integrity of biological membranes is maintained by membrane proteins embedded in the lipid bilayer. A delicate balance of weak interactions between the lipid bilayer and membrane associated proteins regulates cellular homeostasis and disease states. Recently, there has been a growing interest in the construction of in vitro mimics of biological membranes. This allows the study of multiple facets of complex interactions involving lipids and proteins in a simple environment. In recent years, liquid crystal (LC) interfaces decorated with self-assembled layers of phospholipids have evolved as biomimetic systems for systematic study of lipid- protein interactions. Binding of proteins to these phospholipid-laden fluid interfaces can be coupled to the orientational ordering of LCs. In this minireview, we have surveyed the key investigations of these interactions using LC interfaces as the sensing platform. Micrometer thick films of liquid crystals can report interactions ranging from hydrolysis of lipids by enzymatic peptides to membrane induced amyloid formation.
Six types of different nano-metallic oxides were studied as peroxidase-like enzyme. By changing the amounts of nano-metallic oxides, pH value, the concentration of H2O2, reaction time, and so on, the peroxidase-like characteristics of all the six nano-metallic oxides were probed, and four of them (Co3O4, CrOx, NiO, MnOx) have the oxidase-like properties in the absence of H2O2, which is of great importance in the application of degrading phenolic pollutants in waste water.
Despite many benefits, liposomes have still not realized their full potential as vehicles for drug delivery due to the morphological instability. Recently, liposomal nanohybrid cerasomes have been developed as novel drug nanocarriers based on organoalkoxysilane through a sol-gel reaction in combination with self-assembly process. The presence of polyorganosiloxane network on the surface imparts cerasomes higher morphological stability than conventional liposomes and the incorporation of liposomal bilayer structure into cerasomes boosts the biocompatibility in comparision with silica nanoparticles with similar size. Moreover, cerasomes are able to encapsulate various drug molecules and exhibit controlled drug release profile. In addition, cerasomes are easy to be conjugated with biomolecules through silane-coupler chemistry due to the silanols on the surface. Therefore, cerasomes are expected to be ideal drug delivery systems owning to the unique advantages. The present paper will briefly introduce the preparation and properties of cerasomes, followed by reviewing the progress of cerasomes for drug delivery.
Conjugated polymer dots emerge as attractive molecular imaging nanoprobes in living animals for their excellent optical properties including bright fluorescence intensity, excellent photostability, high emission rates, and low intrinsic cytotoxicity. This mini-review summarizes recent advances on near-infrared-emitting poly[2-methoxy-5- (2-ethylhexyloxy)-1,4-phenylenevinylene] polymer dots for in vivo bioimaging. The preparation of near-infrared MEH-PPV polymer dots is firstly discussed, followed by some examples of their applications ranging from lymph node mapping and tumor imaging to long-term tumor tracking.
Endohedral metallic fullerenes (EMFs), featured by the encapsulation of metal ions, molecules and clusters inside the hollow sphere of carbon cage, have drawn great attention in the fullerene research field because of their unique structures and properties. In this minireview, we reviewed the most recent development in this area, focusing mainly on the large EMFs and magnetic EMFs. The relevance between the large carbon cage and cluster was discussed and the paramagnetism and single-molecule magnetism of EMFs, which are controlled by spin single electron and the coupling of f-shell of metal ions, were summarized.
The high strain cyclopropane as σ block model inserted in organic semiconductors to tune the structures and optical properties was investigated by the density functional theory method. The band gaps and absorption peaks of 1,2-disubstituted cyclopropanes were between the corresponding alkanes and olefins. The cis-isomers had higher steric strain between two substituents and lower symmetry than the trans-isomers in ground-state structures. The electronic transitions (S0→S1) were mainly on the aryl parts, which were stronger coherence with surrounding atoms in cis-isomers, while the trans-isomers were on the cyclopropyl. Furthermore, 1,2-disubstituted cyclopropanes (1A, 1B, 2A, 4B) could respond to the charge stimulation, which are potential materials for organic electronics and mechatronics.
Transition metal oxides with nanoscale or special micro-structures are favoured both in scientific research and industry application. Although many methods are developed, there is still a need and a potential payoff for developing a novel and convenient synthetic method. Inspired by nature hydrothermal vent, herein, we develop an ingenious “top-down” method to prepare various transition material compounds, which have diverse and fascinating structures. Our design thought is to etch the A ions by acid from the precursor AxMyOz (A=alkaline and alkaline earth metal, M=transition metal) and leave the MOn/2 or HMO(n+1)/2 behind under the hydrothermal condition. As a result, we obtain various structures like amorphous mesoporous bulk Nb2O5, morphology-re- tained bulk HNbO3 and ZrO2, monodispersed ZrO2 nanoparticles, assembled porous ZrO2 nanostructure, hollow TiO2, and the derived core-shell structure. These materials have great potential application in catalysis and energy storage. We employed hollow TiO2 cube as the high cut-off anode of lithium-ion batteries and harvested excellent performance. After these fruitful attempts, we have found that etching AxMyOz to obtain transition metal compound is a complex reaction containing some different competing reactions, thus allowing us to regulate and control the microstructure of the products by adjusting the reaction condition. We believe there are more interesting structures waiting to be fabricated by similar “top-down” method and these unique materials have great potential in many fields.
Lymph node metastasis is an important aspect for tumor metastasis, which accounts for a majority of cancer death. Non-invasive imaging techniques play a more important role than traditional lymph node biopsy for diagnosis of metastatic lymph nodes. However, non-specific information of lymph node such as size and morphology could only be obtained in traditional imaging techniques, which always bring about mission detection. Thus, lymph-targeted contrast agents are attracting much interest. Presently, most contrast agents are based on the mechanism of passive targeting, which could be affected by the number and function of macrophages in the lymph nodes. Therefore, it is beneficial to study the tumor lymphatic metastases through developing new lymph-targeted contrast agents, which could bring fresh prospect for tumor diagnosis and treatment. The paper reviews the progress of lymph-targeted contrast agents and their diagnosis technology for cancer.
Forward osmosis (FO) has been extensively investigated and demonstrated its advantages in a range of FO applications over the past decade. However, challenges still remain in terms of the lack of both efficient FO membranes and appropriate draw solutes for practical FO applications. To promote the advancement of FO technology, considerable efforts have been made in exploring novel FO membranes and draw solutes in recent years. This paper will provide a short review on the progress of both FO membranes and draw solutes. First of all, a brief overview on FO principle is given. Then the progress in FO technology related to FO membrane and draw solute is presented with specific examples. Finally, challenges and future directions of FO technology in exploring efficient FO membranes and promising draw solutes are also highlighted. This article may provide new insights into the future development of FO technology and promote practical FO applications.
Recycling waste plastics including polypropylene, polyethylene, polyethylene terephthalate, polystyrene, etc, is a very important scientific, social and economic topic. Despite significant advances in recent years, approximately 400 million tons of waste plastics are still disposed by landfill. This is obviously not an effective solution due to plastic’s non-biodegradable character. Aside from mechanical recycling, which turns waste plastics into new products, and thermal recycling, which releases the thermal energy through combustion of waste plastics, chemical recycling converts waste plastics into feedstock for chemicals/materials/fuels production. This article reviews previous work on the pyrolysis and catalytic decomposition route that converted plastics into carbon-based materials, which exhibited extraordinary physical and chemical properties. However, their production processes are both resource and energy-intensive. Therefore, recycling technologies for waste plastics are still at an early stage and more innovation in waste plastic recycling is needed.
In this study, we report the application of magnetic metal-organic frameworks as a novel adsorbent for fast removal of Pb(II) ions from aqueous solution in view of adsorption isotherms, kinetics, thermodynamics, desorption, and adsorbent regeneration. The adsorbent was characterized by PPMS, XRD, TEM and N2 adsorption/desorption measurement. The adsorption follows pseudo-second-order kinetics model and fits the Freundlich adsorption model with the adsorption capacity of 612 mg g–1 for Pb(II) ions. It is a spontaneous and endothermic process controlled by positive entropy change. The used Fe3O4/HKUST-1 could be regenerated effectively and recycled at least four times without significant loss of adsorption capacity.
The mechanism of writing with light depends on photoisomerization ability of light sensitive compounds. The recent advances in photoisomerization phenomenon of azobenzene derivatives are explained on the basis of experimental evidence. Azobenzene derivatives have few limitations in optical storage when it comes to practical and industrial purpose. However, azobenzene derivatives have significant interests because of their excellent light sensitivity and isomerization properties. The fabrication of azobenzene films also plays an important role in the production of an optical storage device. The molecular level layer properties, writing and erasing can be tuned by modification of molecular structures. To explain the concept, writing with light needs high light sensitivity and long duration of thermal back relaxation property. Hence, tuning of thermal back relaxation in the storage process is mainly considered.
A novel multi-modal lymph-targeted contrast agent, ZnO:Gd@hyaluronic acid (HA) nanospheres, is prepared by Gd dopped ZnO quantum dot, modified by silica shell and grafted by HA molecule. The physicochemical properties are characterized and the lymphatic targeting is evaluated in vitro. Moreover, the contrast agent is used for in vivo lymphoma magnetic resonance imaging (MRI). The results show that the ZnO:Gd@HA nanospheres with 19% of quantum yield and 5.8 mM–1•s–1 of relaxivity could be used for in vivo lymphatic targeting studies. Furthermore, they are highly targeted to lymph system in vitro and in vivo, and highlight their MRI in lymph tumor. Thus, the novel MRI contrast agent can be taken up selectively by lymphatic system and used as a potential multi-modal contrast agent in lymphatic system.
A facile and efficient method for preparation of α-oxygenated ketones has been developed via the reaction of terminal aryl alkynes with various iodobenzene dicarboxylates. When bis(trifluoroacetoxy)iodobenzene (PIFA) was used, α-hydroxy ketones were obtained in high to excellent yields. The hypervalent iodine(III) reagents can function as an electrophile, transferrable O-nucleophile, and an excellent leaving group. The protocol represents a direct, atom-efficient and metal-free conversion of alkynes into α-oxygenated ketones under mild conditions.