Latest ArticlesRecent years have witnessed the wide contributions made by transition metal dichalcogenides (TMDCs) to various fields, including the biomedical field. Here, to identify and further promote the development of biomedical TMDCs, we provide a bibliometric analysis of literature regarding TMDCs for biomedical applications. Firstly, general bibliometric distributions of the dataset by year, country, institute, Web of Science category and referenced source are recognized. Following, we carefully explore the research hotspots of the TMDC-related biomedical field, among which biosensing, bioelectronics, cancer theranostics, antibacterial and tissue engineering are identified. The functions of TMDCs in each biomedical scenario, the related properties and research challenges are highlighted. Finally, future prospects are proposed to shed light on the design of novel TMDC-related biomaterials, potential new biomedical applications, as well as their clinical translation.
Single-atom site catalysts (SACs) and two-dimensional materials (2DM) have gradually become two hot topics in catalysis over the past decades. Their combination with each other can further endow the derived SACs with extraordinary properties such as high loading, identical active sites, uniform coordination environment, distinctive metal-support interaction, and enhanced catalytic activities. In this review, we highlight the recent development in this specific research topic according to the types of substrates and focus on their applications in energy conversion field. Additionally, we also make a brief introduction to the synthesis and characterization methods for SACs supported on 2DM (SACs/2DM). Finally, the challenges and perspectives are summarized based on the current development status. It is believed that this work will make contributions to the rational design and fabrication of novel SACs/2DM, promoting their practical energy applications in the future.
Series tunneling across peptides composed of various amino acids is one of the main charge transport mechanisms for realizing the function of protein. Histidine, more frequently found in redox active proteins, has been proved to be efficient tunneling mediator. While how it exactly modulates charge transport in a long peptide sequence remains poorly explored. In this work, we studied charge transport of a model peptide junction, where oligo-alanine peptide was doped by histidine at different position, and the series of peptides were self-assembled into a monolayer on gold electrode with soft EGaIn as top electrode to form molecular junction. It was found that histidine increased the overall conductance of the peptide, meanwhile, its position modulated the conductance as well. Quantitative analysis by transport model and ultraviolet photoelectron spectroscopy (UPS) indicated a sequence dependent energy landscape of the tunneling barrier of the junction. Density-functional theory (DFT) calculation on the electronic structure of histidine doped oligo-alanine peptides revealed localized highest occupied molecular orbital (HOMO) on imidazole group of the histidine, which decreased charge transport barrier.
The application of Si as the anode materials for lithium-ion batteries (LIBs) is still severely hindered by the rapid capacity decay due to the structural damage caused by large volume change (> 300%) during cycling. Herein, a three-dimensional (3D) aerogel anode of Si@carbon@graphene (SCG) is rationally constructed via a polydopamine-assisted strategy. Polydopamine is coated on Si nanoparticles to serve as an interface linker to initiate the assembly of Si and graphene oxide, which plays a crucial role in the successful fabrication of SCG aerogels. After annealing the polydopamine is converted into N-doped carbon (N-carbon) coatings to protect Si materials. The dual protection from N-carbon and graphene aerogels synergistically improves the structural stability and electronic conductivity of Si, thereby leading to the significantly improved lithium storage properties. Electrochemical tests show that the SCG with optimized graphene content delivers a high capacity (712 mAh/g at 100 mA/g) and robust cycling stability (402 mAh/g at 1 A/g after 1500 cycles). Furthermore, the full cell using SCG aerogels as anode exhibits a reversible capacity of 187.6 mAh/g after 80 cycles at 0.1 A/g. This work provides a plausible strategy for developing Si anode in LIBs.
Ammonium vanadate has been considered as a competitive high-performance cathode material for aqueous Zn-ion batteries. However, it still suffers from insufficient rate capability and poor cyclability due to the low electronic conductivity. Herein, (NH4)2V6O16·0.9H2O nanobelts with reduced graphene oxide (RGO) modification are synthesized by one-step hydrothermal reaction. Benefiting from the addition of RGO, an excellent electrochemical performance of (NH4)2V6O16·0.9H2O@RGO nanobelts can be obtained. The (NH4)2V6O16·0.9H2O@RGO displays a high-rate capacity and a high energy density of 386 Wh/kg at 72 W/kg. In particular, after 1000 cycles at 5 A/g, the capacity remains at 322 mAh/g with 92.8% capacity retention. In addition, the key reaction mechanisms of reversible Zn2+insertion/extraction in (NH4)2V6O16·0.9H2O@RGO are clarified.
We report a series of highly stable metallophthalocyanine-based covalent organic frameworks (MPc-dx-COFs) linked by robust 1, 4-dioxin bonds constructed through nucleophilic aromatic substitution (SNAr) reaction. The chemical structures and crystallinity of the COFs largely remain unchanged even after treating with boiling water (90 ℃), concentrated acids (12 mol/L HCl) or bases (12 mol/L NaOH), oxidizing (30% H2O2) or reducing agents (1 mol/L NaBH4) for three days due to their stable M-Pc building blocks and resilient dioxin linkers. With metallated phthalocyanine active sites regularly arranged in the stable framework structures, MPc-dx-COFs can be directly used as efficient electrocatalysts for the oxygen reduction reaction (ORR) without pyrolysis treatment that has commonly been used in previous studies.
The design of assembling high-nuclearity transition-lanthanide (3d-4f) clusters along with excellent magnetocaloric effect (MCE) is one of the most prominent fields but is extremely challenging. Herein, two heterometallic metal coordination polymers are constructed via the "carbonate-template" method, formulated as {[Gd18Ni24(IDA)22(CO3)7(μ3-OH)32(μ2-OH)3(H2O)5Cl]·Cl8·(H2O)14}n and {[Eu18Ni23.5(IDA)22(CO3)7(μ3-OH)32(H2O)5(IN)(CH3COO)2(NH2CH2COO)Cl]·Cl6·(H2O)17}n [abbreviated as 1-(Gd18Ni24)n and 2-(Eu18Ni23.5)n respectively; H2IDA = iminodiacetic acid; HIN = isonicotinic acid]. Concerning the structures, compounds 1-(Gd18Ni24)n and 2-(Eu18Ni23.5)n both feature the one-dimensional (1D) chain-like structure which is rarely reported in high-nuclearity metal complexes. Meanwhile, the large presences of Gd3+ ions in compound 1-(Gd18Ni24)n are conducive to the fantastic MCE, and the value of -∆Sm is 35.30 J kg-1 K-1 at 3.0 K and ∆H = 7.0 T. And more significantly, compound 1-(Gd18Ni24)n shows the large low-field magnetic entropy change (-∆Sm = 20.95 J kg-1 K-1 at 2.0 K and ∆H = 2.0 T) among the published 3d-4f mixed metal clusters.
Developing large-scale electrocatalysts using molecular complexes for the oxygen evolution reaction (OER) is of great importance. Herein, four cobalt porphyrins and corroles are deposited on electrode substrates using a simple and fast electropolymerization method. Our results showed that Co-1-P@CC, formed by electropolymerizing Co tetrakis(p-N-pyrrolylphenyl)porphyrin (Co-1-P) on carbon cloth (CC), is the most active OER catalyst in the examined Co porphyrins and corroles in alkaline aqueous solutions by displaying an onset overpotential of 380 mV. Long-term electrolysis tests confirmed the stability of these electropolymerized films by functioning as OER electrocatalysts.
The bio-nanotechnological fabrication of high-surface-area carbons has attracted widespread interest in supercapacitor applications by using readily-available natural products as raw materials or bio-templates, and is expected to refine on pore accessibility for compact energy storage. Here, a renovated design strategy of semi-biomass interpenetrating polymer network (IPN) derived carbon is demonstrated through physically knitting the biomacromolecule (sodium alginate, SA) polymeric chains into the highly crosslinked resorcinol-formaldehyde (RF) network and subsequent thermochemical conversion. Molecule-level interlacing forces in such IPN efficiently relieve the RF skeleton shrinkage when producing carbon, while the other SA network addresses the macrophase separation issue to sacrifice as an in-knitted porogen and a morphology-directing agent. As a result, porous carbon globules are equipped with moss-like surfaces and interconnected pore architecture for high accessible electrode surface (1013 m2/g), and efficient electrochemical responses are reached with the specific capacitance of 312 F/g at 1 A/g. Taking the advantage of 9 mol/kg NaClO4 complex-solvent electrolyte, the voltage window is extended to 2.4 V, endowing the two-electrode device with the high energy delivery of 32.3 Wh/kg at 240 W/kg.
Developing metal-organic framework (MOF)-based materials with good cyclic stability is the key to their practical application. Fluorinated organic compounds are usually highly chemically stability due to the high electronegativity of fluorine. Also, the pillared-layer structures based on coordination bonds have better structure and thermal stability than those based on hydrogen bonds. Herein, the fluorinated pillared-layer [Ni(2, 3, 4, 5-tetrafluorobenzoic acid)(4, 4′-bipyridine)]n MOF ([Ni(TFBA)(Bpy)]n) materials were constructed through a facile room-temperature solution reaction and used as electrode materials for supercapacitors. Surprisingly, the size/morphology of Ni(TFBA)(Bpy)]n MOFs could be adjusted by varying the synthesis time. Benefting from the short ion diffusion length, unique pillar-layer structure, and strong intercomponent synergy of organic ligands, the Ni(TFBA)(Bpy)]n MOF microrods showed a higher electrochemical energy storage capability than bulk MOFs. At the same time, compared to the non-fluorinated [Ni(benzoic acid)(Bpy)]n MOFs (31.5% capacitance decay), the fluorinated Ni(TFBA)(Bpy)]n MOFs have a higher cycle stability with only 2.6% capacitance loss after 5000 cycles at 3 mA/cm2.