Fabrication of Zn-Air Battery with High Output Capacity Under Ultra-Large Current.

Zn-air battery (ZAB) is advocated as a more viable option in the new-energy technology. However, the limited-output capacity at a high current density impedes the driving range in power batteries substantially. Here, a novel heterojunction-based graphdiyne (GDY) and Ag29Cu7 alloy quantum dots (Ag29Cu7 QDs/GDY) for constructing a high-performance aqueous ZAB are fabricated. The as-fabricated ZAB achieves discharge at up to 100 mA cm-2 (the highest value ever reported) along with a remarkable output specific capacity of 786.2 mAh g-1 Zn , which is mainly benefitted from the binary-synergistic effect toward a stable triple-phase interface for air electrode induced by the Ag29Cu7 QDs and GDY in harsh base, together with the decreasing reaction energy barrier and polarization. The results outperform the superior reports discharging at low current and will bring breakthrough progress toward the practical applications of ZAB on large power supply facilities.

Two-Dimensional Carbon Graphdiyne: Advances in Fundamental and Application Research.

Graphdiyne (GDY), a rising star of carbon allotropes, features a two-dimensional all-carbon network with the cohybridization of sp and sp2 carbon atoms and represents a trend and research direction in the development of carbon materials. The sp/sp2-hybridized structure of GDY endows it with numerous advantages and advancements in controlled growth, assembly, and performance tuning, and many studies have shown that GDY has been a key material for innovation and development in the fields of catalysis, energy, photoelectric conversion, mode conversion and transformation of electronic devices, detectors, life sciences, etc. In the past ten years, the fundamental scientific issues related to GDY have been understood, showing differences from traditional carbon materials in controlled growth, chemical and physical properties and mechanisms, and attracting extensive attention from many scientists. GDY has gradually developed into one of the frontiers of chemistry and materials science, and has entered the rapid development period, producing large numbers of fundamental and applied research achievements in the fundamental and applied research of carbon materials. For the exploration of frontier scientific concepts and phenomena in carbon science research, there is great potential to promote progress in the fields of energy, catalysis, intelligent information, optoelectronics, and life sciences. In this review, the growth, self-assembly method, aggregation structure, chemical modification, and doping of GDY are shown, and the theoretical calculation and simulation and fundamental properties of GDY are also fully introduced. In particular, the applications of GDY and its formed aggregates in catalysis, energy storage, photoelectronic, biomedicine, environmental science, life science, detectors, and material separation are introduced.

Graphdiyne and Its Derivatives as Efficient Charge Reservoirs and Transporters in Semiconductor Devices.

2D graphdiyne (GDY), which is composed of sp and sp2 hybridized carbon atoms, is a promising semiconductor material with a unique porous lamellar structure. It has high carrier mobility, tunable bandgap, high density of states, and strong electrostatic interaction ability with ions and organic functional units. In recent years, interests in applying GDYs (GDY and its derivatives) in semiconductor devices have been growing rapidly, and great achievements have been made. Attractively, GDYs could act as efficient reservoirs and transporters for both carriers and ions, which endows them with enormous potential in future novel optoelectronics. In this review, the progress in this field is systematically summarized, aiming to bring an in-depth insight into the GDYs' intrinsic uniqueness. Particularly, the effects of GDYs on carrier dynamics and ionic interactions in various semiconductor devices are succinctly described, analyzed, and concluded.

Graphdiyne oxide nanosheets display selective anti-leukemia efficacy against DNMT3A-mutant AML cells.

DNA methyltransferase 3 A (DNMT3A) is the most frequently mutated gene in acute myeloid leukemia (AML). Although chemotherapy agents have improved outcomes for DNMT3A-mutant AML patients, there is still no targeted therapy highlighting the need for further study of how DNMT3A mutations affect AML phenotype. Here, we demonstrate that cell adhesion-related genes are predominantly enriched in DNMT3A-mutant AML cells and identify that graphdiyne oxide (GDYO) display an anti-leukemia effect specifically against these mutated cells. Mechanistically, GDYO directly interacts with integrin ß2 (ITGB2) and c-type mannose receptor (MRC2), which facilitate the attachment and cellular uptake of GDYO. Furthermore, GDYO binds to actin and prevents actin polymerization, thus disrupting the actin cytoskeleton and eventually leading to cell apoptosis. Finally, we validate the in vivo safety and therapeutic potential of GDYO against DNMT3A-mutant AML cells. Collectively, these findings demonstrate that GDYO is an efficient and specific drug candidate against DNMT3A-mutant AML.

Gas permeation through graphdiyne-based nanoporous membranes.

Nanoporous membranes based on two dimensional materials are predicted to provide highly selective gas transport in combination with extreme permeance. Here we investigate membranes made from multilayer graphdiyne, a graphene-like crystal with a larger unit cell. Despite being nearly a hundred of nanometers thick, the membranes allow fast, Knudsen-type permeation of light gases such as helium and hydrogen whereas heavy noble gases like xenon exhibit strongly suppressed flows. Using isotope and cryogenic temperature measurements, the seemingly conflicting characteristics are explained by a high density of straight-through holes (direct porosity of ∼0.1%), in which heavy atoms are adsorbed on the walls, partially blocking Knudsen flows. Our work offers important insights into intricate transport mechanisms playing a role at nanoscale.

The Underlying Function and Structural Organization of the Intracellular Protein Corona on Graphdiyne Oxide Nanosheet for Local Immunomodulation.

Nanomaterial-biology interaction is the critical step in the fate of biomedical nanomedicines, influencing the consequent biological outcomes. Herein, we present two-dimensional carbon-based nanomaterials-graphdiyne oxide (GDYO) nanosheets that interact with an intracellular protein corona consisting of signal transducer and activator of transcription 3 (STAT3), inducing the reeducation of immunosuppressive macrophages. The interaction at the GDYO-STAT3 interface, driven by structure matching, hydrogen bonding, and salt bridges, simultaneously triggers the immune response in the tumor microenvironment, facilitating cancer immunotherapy. For the first time, our data reveal an interaction mechanism between the nanoparticle-protein interfaces inevitably formed inside the cells that determines the macrophage phenotype. Our results suggest that GDYO nanosheets could be applied for local immunomodulation due to their function and structural organization of the intracellular protein corona occurred inside macrophages.

Multifunctional Graphdiyne-Cerium Oxide Nanozymes Facilitate MicroRNA Delivery and Attenuate Tumor Hypoxia for Highly Efficient Radiotherapy of Esophageal Cancer.

Radioresistance is an important challenge for clinical treatments. The main causes of radioresistance include hypoxia in the tumor microenvironment, the antioxidant system within cancer cells, and the upregulation of DNA repair proteins. Here, a multiple radiosensitization strategy of high-Z-element-based radiation enhancement is designed, attenuating hypoxia and microRNA therapy. The novel 2D graphdiyne (GDY) can firmly anchor and disperse CeO2 nanoparticles to form GDY-CeO2 nanocomposites, which exhibit superior catalase-mimic activity in decomposing H2 O2 to O2 to significantly alleviate tumor hypoxia, promote radiation-induced DNA damage, and ultimately inhibit tumor growth in vivo. The miR181a-2-3p (miR181a) serum levels in patients are predictive of the response to preoperative radiotherapy in locally advanced esophageal squamous cell carcinoma (ESCC) and facilitate personalized treatment. Moreover, miR181a can act as a radiosensitizer by directly targeting RAD17 and regulating the Chk2 pathway. Subsequently, the GDY-CeO2 nanocomposites with miR181a are conjugated with the iRGD-grafted polyoxyethylene glycol (short for nano-miR181a), which can increase the stability, efficiently deliver miR181a to tumor, and exhibit low toxicity. Notably, nano-miR181a can overcome radioresistance and enhance therapeutic efficacy both in a subcutaneous tumor model and human-patient-derived xenograft models. Overall, this GDY-CeO2 nanozyme and miR181a-based multisensitized radiotherapy strategy provides a promising therapeutic approach for ESCC.

Coaxial spinning fabricated high nitrogen-doped porous carbon walnut anchored on carbon fibers as anodic material with boosted lithium storage performance.

Commercial graphite with low theoretical capacity cannot meet the ever-increasing requirement demands of lithium-ion batteries (LIBs) caused by the rapid development of electric devices. Rationally designed carbon-based nanomaterials can provide a wide range of possibilities to meet the growing requirements of energy storage. Hence, the porous walnut anchored on carbon fibers with reasonable pore structure, N-self doping (10.2 at%) and novel structure and morphology is designed via interaction of inner layer polyethylene oxide and outer layer polyacrylonitrile and polyvinylpyrrolidone during pyrolysis of the obtained precursor, which is fabricated by coaxial electrospinning. As an electrode material, the as-made sample shows a high discharge capacity of 965.3 mA h g-1 at 0.2 A g-1 in the first cycle, retains a capacity of 819.7 mA h g-1 after 500 cycles, and displays excellent cycling stability (475.2 mA h g-1 at 1 A g-1 after 1000 cycles). Moreover, the capacity of the electrode material still keeps 260.5 mA h g-1 at 5 A g-1 after 1000 cycles. Therefore, the obtained sample has a bright application prospect as a high performance anode material for LIBs. Besides, this design idea paves the way for situ N-enriched carbon material with novel structure and morphology by coaxial electrospinning.

A Graphdiyne Oxide-Based Iron Sponge with Photothermally Enhanced Tumor-Specific Fenton Chemistry.

Fenton reaction-mediated oncotherapy is an emerging strategy which uses iron ions to catalytically convert endogenous hydrogen peroxide into hydroxyl radicals, the most reactive oxygen species found in biology, for efficient cancer therapy. However, Fenton reaction efficiency in tumor tissue is typically limited due to restrictive conditions. One strategy to overcome this obstacle is to increase the temperature specifically at the tumor site. Herein, a tumor-targeting iron sponge (TTIS) nanocomposite based on graphdiyne oxide, which has a high affinity for iron is described. TTIS can accumulate in tumor tissue by decoration with a tumor-targeting polymer to enable tumor photoacoustic and magnetic resonance imaging. With its excellent photothermal conversion efficiency (37.5%), TTIS is an efficient photothermal therapy (PTT) agent. Moreover, the heat produced in the process of PTT can accelerate the release of iron ions from TTIS and simultaneously enhance the efficiency of the Fenton reaction, thus achieving a combined PTT and Fenton reaction-mediated cancer therapy. This work introduces a graphdiyne oxide-based iron sponge that exerts an enhanced antitumor effect through PTT and Fenton chemistry.

Graphdiyne:Structure of Fluorescent Quantum Dots.

Graphdiyne (GDY) as an emerging two-dimensional carbon allotrope exhibits excellent performance in energy chemistry, catalytic chemistry, optoelectronics, electronics, etc. because of the unique structure combining an sp- and sp2 -hybrid carbon network. However, the poor solubility of pristine GDY is a major obstacle to its applications in many fields. Proposed here is a facile strategy to control the preparation of GDY quantum dots (GDY-Py QDs), in which pyrene groups are covalently linked to GDY by using a Sonogashira cross-coupling reaction. The as-prepared GDY-Py QDs, with an average diameter of about 3±0.1 nm, show superior dispersibility in many organic solvents and water. The GDY-Py QDs display not only bright fluorescent with a high relative quantum yield (QY) of 42.82 %, but they are also well-behaved as contrast agents in cell imaging. The GDY-Py QDs are bestowed with high stability and non-cytotoxicity, and exhibit long fluorescent times, and have potential for optical imaging and biomedical applications.

DNA-Guided Room-Temperature Synthesis of Single-Crystalline Gold Nanostructures on Graphdiyne Substrates.

Nobel metal nanoparticles with tunable morphologies are highly desirable due to their unique electronic, magnetic, optical, and/or catalytic features. Here we report the use of multilayered graphdyine (GD) as a substrate for the reductant-free, room-temperature synthesis of single-crystal Au nanostructures with tunable morphology. We find that the GD template rich in sp-carbon atoms possesses high affinity with Au atoms on the {111} facets, and that the intrinsic reductivity of GD facilitates the rapid growth of Au nanoplates. The introduction of single-stranded DNA strands further results in the synthesis of Au nanostructures with decreased anisotropy, i.e., polygons and flower-like nanoparticles. The DNA-guided tunable Au growth arises from the strong adsorption of DNA on the GD template that alters the uniformity of the interface, which provides a direct route to synthesize Au nanostructures with tailorable morphology and photonic properties.

Intensified C≡C Stretching Vibrator and Its Potential Role in Monitoring Ultrafast Energy Transfer in 2D Carbon Material by Nonlinear Vibrational Spectroscopy.

In this work, an intensity-enhanced C≡C stretching infrared (IR) absorption is observed in hexakis[(trimethylsilyl)ethynyl]benzene (HTEB), whose IR transition dipole magnitude becomes comparable to that of a typical C═O stretch, and the enhancement is believed to be due to a joint effect of π-π conjugation and hyperconjugation associated with a terminal trimethylsilyl group. Using dynamical time-dependent two-dimensional infrared (2D IR) spectroscopy, a picosecond intramolecular energy redistribution process is observed between two nondegenerate C≡C stretching modes, whose symmetry breaking is attributed to a noncovalent halogen-bonding interaction between HTEB and solvent CH2Cl2. The rigid structure of HTEB and limited structural dynamics are also inferred from the insignificant initial spectral diffusion value extracted from the 2D IR spectra. This work provides the first nonlinear infrared investigation of the conventionally weak C≡C stretch. The methods outlined are particularly important for detailed understanding of the structure-related processes such as vibrational energy transfer in novel C≡C species containing materials such as graphdiyne.

Graphdiyne: synthesis, properties, and applications.

Graphdiyne (GDY), a new two-dimensional (2D) carbon allotrope, has been receiving increased attention. Its unique sp-sp2 carbon atoms, uniform pores, and highly π-conjugated structure provide promising potential in practical applications, such as gas separation, catalysis, water remediation, humidity sensor, and energy-related fields. In the recent years, considerable efforts have been expended toward the development of well-defined GDY. However, GDY materials still face numerous challenges, including the need for a more thorough understanding of the growth mechanism, strategies for synthesizing one- or few-layer single-crystalline GDY films, characterization of basic physicochemical properties, and achievement of promising applications. This review aims at providing a comprehensive update on the synthesis of GDY and GDY-based materials, as well as their properties, including structural, electronic, mechanical, and spectral properties, and their applications in nanotechnology.

High-Yield and Damage-free Exfoliation of Layered Graphdiyne in Aqueous Phase.

The two-dimensional carbon material graphdiyne (GDY) holds great promise as a semiconductor and porous material, however, exfoliation of bulk GDY into single- or few-layered GDY in the aqueous phase remains a challenge. We report an efficient method for the damage-free exfoliation of bulk GDY into single- or few-layered GDY with high yield in an aqueous solution of inorganic salts (e.g., Li2 SiF6 ). This was confirmed by spherical-aberration-corrected scanning transmission electron microscopy, scanning/transmission electron microscopy, atomic force microscopy, Fourier transform infrared/Raman spectroscopy, X-ray photoelectron spectroscopy. The method gives high exfoliation efficiency (75 wt %) without creating additional structural defects or oxides in the exfoliated GDY. Theoretical calculations suggest that non-covalent adsorption of the anion, diffusion of the cation, and subsequent repulsive forces between adjacent flakes are the main driving force for the efficient exfoliation.

Graphdiyne Sponge for Direct Collection of Oils from Water.

Although several sponge-like sorbents have been developed to treat oil spills and chemical leakages, under harsh conditions (e.g., strong acid or alkali; oils on the sea) their efficiencies can be rather limited. Herein, we provide a graphdiyne sponge that is capable of collecting oil pollution effectively. This graphdiyne sponge exhibits excellent adsorption capacity (up to 160 times its own weight), robust stability (even when immersed in strong acid and alkali for 7 days), and remarkable recyclability (up to 100 times). These features suggest that this new adsorbent material might find applicability in the cleanup of oil spills and many organic pollutants under realistic conditions.

Ultrathin Nanosheet of Graphdiyne-Supported Palladium Atom Catalyst for Efficient Hydrogen Production.

Atomic catalysts are promising alternatives to bulk catalysts for the hydrogen evolution reaction (HER), because of their high atomic efficiencies, catalytic activities, and selectivities. Here, we report the ultrathin nanosheet of graphdiyne (GDY)-supported zero-valent palladium atoms and its direct application as a three-dimensional flexible hydrogen-evolving cathode. Our theoretical and experimental findings verified the successful anchoring of Pd0 to GDY and the excellent catalytic performance of Pd0/GDY. At a very low mass loading (0.2%: 1/100 of the 20 wt % Pt/C), Pd0/GDY required only 55 mV to reach 10 mA cm-2 (smaller than 20 wt % Pt/C); it showed larger mass activity (61.5 A mgmetal-1) and turnover frequency (16.7 s-1) than 20 wt % Pt/C and long-term stability during 72 hr of continuous electrolysis. The unusual electrocatalytic properties of Pd0/GDY originate from its unique and precise structure and valence state, resulting in reliable performance as an HER catalyst.

Immobilized Ferrous Ion and Glucose Oxidase on Graphdiyne and Its Application on One-Step Glucose Detection.

Graphdiyne (GDY) is a novel two-dimensional (2D) carbon allotrope with sp-hybridized carbon atoms and hexagonal rings. Because of its unique structure and electronic property, GDY was reported as a promising candidate applied in energy storage, catalysis, biosensing and so on. However, using GDY as a platform to immobilize metal ion or enzyme was still not reported. Here, we presented a GDY-based composite with dual-enzyme activity by immobilizing ferrous ion and glucose oxidase onto GDY sheet. GDY showed great adsorption capacity and maintained the high catalytic activity of ferrous ion. The ferrous ion preferred to adsorb in between the neighboring two C-C triple bonds of GDY with lower adsorption energy (-5.64 eV) if compared to graphene (-1.69 eV). Meanwhile, GDY exhibited the ability of adsorbing glucose oxidase while did not obviously influence the structure and catalytic activity of the enzyme. The as-prepared composite was successfully used in one-step blood glucose detection. This work provides a new insight on ion and enzyme immobilization by 2D material.

Graphdiyne-Promoted Highly Efficient Photocatalytic Activity of Graphdiyne/Silver Phosphate Pickering Emulsion Under Visible-Light Irradiation.

As a new kind of two-dimensional carbon allotrope, graphdiyne (GDY) consists of sp- and sp2-hybridized carbon atoms and has recently been used for developing highly efficient photocatalytic systems because of its unique properties. In this study, we find that GDY can form a Pickering emulsion with silver phosphate (Ag3PO4) nanoparticles that exhibits largely enhanced photocatalytic activity in the visible-light region. In this system, Ag3PO4 acts as a photocatalytically active semiconductor with GDY as the hydrophobic nanostructure. Photocatalytic activity of the Ag3PO4/GDY-based Pickering emulsion toward the photodegradation of methylene blue (MB) and photooxidation of water is investigated under visible-light irradiation. Compared to previous Ag3PO4/CNT- or Ag3PO4/graphene-based Pickering emulsions, the Ag3PO4/GDY-based emulsion efficiently catalyzes MB degradation with a higher apparent rate constant k being ∼0.477 min-1, while for water oxidation its photocatalytic activity is also improved by 1.89 and 1.75 times, respectively. Such an enhancement in the photocatalytic activity is mainly ascribed to the capability of GDY in acting as an acceptor of the photogenerated electrons from Ag3PO4 nanoparticles and in facilitating the hole transportation as well as in reducing Ag+ to Ag0. This study demonstrates that GDY is a new candidate with a promising future in developing photocatalytic systems with high efficiency for real applications.

Overall water splitting by graphdiyne-exfoliated and -sandwiched layered double-hydroxide nanosheet arrays.

It is of great urgency to develop efficient, cost-effective, stable and industrially applicable electrocatalysts for renewable energy systems. But there are still few candidate materials. Here we show a bifunctional electrocatalyst, comprising graphdiyne-exfoliated and -sandwiched iron/cobalt layered double-hydroxide nanosheet arrays grown on nickel foam, for the oxygen and hydrogen evolution reactions. Theoretical and experimental data revealed that the charge transport kinetics of the structure were superior to iron/cobalt layered double-hydroxide, a prerequisite for improved electrocatalytic performance. The incorporation with graphdiyne increased the number of catalytically active sites and prevented corrosion, leading to greatly enhanced electrocatalytic activity and stability for oxygen evolution reaction, hydrogen evolution reaction, as well as overall water splitting. Our results suggest that the use of graphdiyne might open up new pathways for the design and fabrication of earth-abundant, efficient, functional, and smart electrode materials with practical applications.

Charge transfer drives anomalous phase transition in ceria.

Ceria has conventionally been thought to have a cubic fluorite structure with stable geometric and electronic properties over a wide temperature range. Here we report a reversible tetragonal (P42/nmc) to cubic (Fm-3m) phase transition in nanosized ceria, which triggers negative thermal expansion in the temperature range of -25 °C-75 °C. Local structure investigations using neutron pair distribution function and Raman scatterings reveal that the tetragonal phase involves a continuous displacement of O2- anions along the fourfold axis, while the first-principles calculations clearly show oxygen vacancies play a pivotal role in stabilizing the tetragonal ceria. Further experiments provide evidence of a charge transfer between oxygen vacancies and 4f orbitals in ceria, which is inferred to be the mechanism behind this anomalous phase transition.