Π-conjugated Structure Research Articles

Effects of Conformation on Doping Efficiency in π-Extended Bipyranylidene Molecules: Relationship between Molecular Structure and Electron-Doping Ability for Developing n-Type Organic Thermoelectrics

Abstract Electron doping is an essential process for developing n-type organic thermoelectric materials, and thus the search for efficient n-type dopants is critically important. By replacing the central 1-methylpyrrole ring in 2,5-bis((2,6-diphenyl-4H-pyran-4-ylidene)methyl)-1-methylpyrrole (1) with electron-rich 3,4-ethylenedioxythiophene and 2,2′-bis(3,4-ethylenedioxythiophene) moieties, we synthesized new candidate molecules (2 and 3, respectively) as n-type dopants. The single-crystal X-ray analyses of 1 and 3 elucidated that 3 has a totally planar π-conjugated structure over the whole molecule, whereas 1 has a non-planar structure. Although the energy levels of the highest occupied molecular orbitals of 1–3 evaluated by the electrochemical measurement in solution were not significantly different, the work function of 3 thin film evaluated by the Kelvin probe method was slightly higher than those of 1 and 2. Furthermore, 3 was capable of electron-doping to an n-type semiconducting polymer, poly(benzimidazobenzophenanthroline) (BBL), and the resulting doped BBL showed decent thermoelectric characteristics with the power factor of 1.25 × 10−3 µW m−1 K−2, which was higher by one order of magnitude than those of 1- and 2-doped BBL thin films. These results imply that the high planarity of 3 can contribute to electron-doping ability, which could be useful information for further development of n-type dopants for organic thermoelectric applications.

Phenothiazine metal-organic framework materials with excellent third-order nonlinear properties

The third-order nonlinear optical material with excellent performance is a molecule with a large π-conjugated structure for absorption structure and a high degree of delocalization. Nitrogen-sulfur derivatives have lone pairs of electrons in their N and S atoms, which makes them have a strong intramolecular charge transfer ability, which is conducive to the formation of donor-acceptor molecules. In this paper, phenothiazine is used as the matrix structure of the third-order nonlinear optical material, modified, and then metal coordination is performed to obtain [Zn(Py)2Cl2]n and [Cd(Py)2Cl2]n. Its structure is characterized by infrared spectroscopy, single crystal X-ray diffraction and powder X-ray diffraction. The morphology of the material was characterized by scanning electron microscopy. The photophysical properties, thermal properties and third-order nonlinear properties were tested, and the theoretical verification was carried out with the DFT calculation method, and the relationship between the structure and the third-order nonlinear properties was summarized. The experimental results show that phenothiazine has good electron donating ability, the two-photon absorption coefficient β is between 1.334–38.400 × 10−10 m/W, and the third-order nonlinear polarizability χ(3) is between 2.752–79.247 × 10−11 esu, The second-order hyperpolarizability γ of the ligand molecule is 5.213 × 10−34 esu. The χ(3) values of [Zn(Py)2Cl2]n and [Cd(Py)2Cl2]n are 4 orders of magnitude higher than ordinary α-quartz (χ(3) = 2.6 × 10−14 esu).

An Ultrafast, Durable, and High-Loading Polymer Anode for Aqueous Zinc-Ion Batteries and Supercapacitors.

Zn metal has shown promise as an anode material for grid-level energy storage, yet is challenged by dendritic growth and low Coulombic efficiency. Herein, an ultrafast, stable, and high-loading polymer anode for aqueous Zn-ion batteries and capacitors (ZIBs and ZICs) is developed by engineering both the electrode and electrolyte. The anode polymer is rationally prepared to have a suitable electronic structure and a large π-conjugated structure, whereas the electrolyte is manufactured based on the superiority of triflate anions over sulfate anions, as analyzed and confirmed via experiments and simulations. This dual engineering results in an optimal polymer anode with a low discharge potential, near-theoretical capacity, ultrahigh-loading capability (≈50mg cm-2 ), ultrafast rate (100 A g-1 ), and ultralong lifespan (one million cycles). Its mechanism involves reversible Zn2+ /proton co-storage at the carbonyl site. When the polymer anode is coupled with cathodes for both ZIB and ZIC applications, the devices demonstrate ultrahigh power densities and ultralong lifespans, far surpassing those of corresponding Zn-metal-based devices.

Study on Excited State Kinetics and Optical Limiting Performance of Triphenylamine-Based Chalcone Derivatives: Effect of the Molecular π-Conjugated Structure.

Optical limiting (OL) is an important application of nonlinear optics. Summarizing the structure-property relationship of organic materials is an effective means to develop superior optical limiters. In this work, two triphenylamine-based chalcone derivatives T1 and T2 with different peripheral substituent groups were synthesized to study their transient kinetics and nonlinear optical (NLO) absorption performance. The transient absorption spectrum (TAS) of compounds T1 and T2 in solvents of varying polarities visualizes the intramolecular charge transfer (ICT) processes between the local excited state (LES) and the charge transfer state (CTS). Nanosecond Z-scan experiment and hole-electron analysis indicate that all compounds have excellent reverse saturated absorption (RSA) performance at 532 nm and T1 exhibits stronger RSA than T2 due to the stronger ICT performance of T1 caused by the halogen effect. Degenerate pump-probe experiment shows that the ESA of T2 at 532 nm is significantly enhanced by expanding the molecular π-conjugation. Under the premise of consistent linear transmittance (78%), compound T2 shows better OL performance than compound T1 at 532 nm in the nanosecond time domain. The OL thresholds of T1 and T2 are 3.72 and 0.72 J cm-2, respectively, which are better than those of the most reported OL materials. Our research shows that simple and common chalcone derivatives exhibit amazing NLO performance through a reasonable design.

Flexible ligand for Metal-Organic frameworks with simultaneous Large-Pore and antenna effect emission

Polycyclic aromatic ligands improve the pore size of metal–organic frameworks (MOFs), but their big π-conjugation structure forbids energy transfer for antenna effect emission. Thus, large-pore and antenna effect are a dilemma even their combination could improve the efficiency of MOFs. Herein, we construct a flexible ligand, 1,3,5-tris(5-methoxy-1,3-benzene dicarboxylic acid)benzene (L1) by attaching three isophthalic acids (L2) to a benzene ring through flexible –CH2-O- bonds. L1 retains the optical properties of L2 for antenna effect and expands the molecular size for MOFs with large pore. Single-crystal result of the MOFs obtained with L1 and Eu3+, Tb3+, or Gd3+ reveals the aperture of 18 Å and the density of 1.2 g/mL. L1 excites Eu3+ and Tb3+ ions for their antenna effect emission. The –CH2-O- group tunes the energy transfer for dual-emission at 360 and 623 nm from L1-Eu MOF under single excitation of 290 nm. The dual-emission is used for ratiometric fluorescence detection of phosphate (PO43-) and adenosine-5′-triphosphate (ATP). We reveal the effect of porous structure of MOFs on the response speed and range. The pore size affects the target entrance as L1-Eu MOF shows faster response to PO43- and ATP than L2-Eu MOF. Moreover, fast diffusion dynamics of a target is observed in large-pore MOFs for good linear response. The relative specific surface area affects the linear range as a narrower range was observed for ATP than PO43-. Thus, flexible ligand is effective to expand the aperture, improve optical properties, and study the response mechanism for the extensive applications of MOFs.

One-pot synthesis of single-component graphene quantum dots for stable and bright white luminescence films as a phosphor

Graphene quantum dots (GQDs) with the merits of low cost, non-toxicity and unique optical properties have attracted much attention in various fields. However, it is still challenging to synthesize one-component white-light emissive GQDs with high photoluminescence quantum yield (PLQY). In this work, 1,5-diaminonaphthalene (1,5-DAN) and tartaric acid (TA) were smartly introduced as the precursors in a solvothermal reaction. As a matter of fact, the obtained GQDs exhibited a blue-emission band centered at 413 nm (surface state emission) and a yellow-green-emission band at 558 nm (core-state emission) might be originated from various surface functional groups and inner π-conjugated structure, respectively, which enabled white luminescence of the GQDs. It reveals that both of 1,5-DAN and TA played a vital role on forming the yellow-green-emission band by providing the components of benzene rings and CC/CO bonds, respectively. Moreover, the white-light emissive GQDs (W-GQDs) with the mean size of ∼2.7 nm exhibited a PLQY as high as 28.68% and good photostability under the 365 nm UV light and daylight. A PLQY up to 9.32% can still be achieved in the solid GQDs/polyvinyl alcohol film. Therefore, our prepared GQDs are promising for white light emitting diodes application.

Carbon-supported nano tungsten bronze aerogels with synergistically enhanced photothermal conversion performance: Fabrication and application in solar evaporation

Solar interfacial evaporation is an effective and sustainable strategy to solve the shortage of fresh water. Nowadays, fully converting the near-infrared light with significant thermal effect, and reducing the energy loss in evaporation stage are the key factors to achieve higher evaporation rate. Herein, the nano cesium tungsten bronze (Cs0.32WO3) with exceptional near-infrared absorption property was loaded on reduced graphene oxide-carbon nanotubes (rGO-CNTs) composite aerogel, drastically enhancing the evaporation efficiency from 61.0% to 85.9%, which can be explained by the remarkable synergistic effect between rGO-CNTs and nano Cs0.32WO3 in improving the photothermal conversion performance. As a result, the solar evaporators assembled by the fabricated rGO-CNTs-Cs0.32WO3 aerogels and corn straw grooves achieved an evaporation rate of 1.93 kg m−2 h−1, exceeding the previously-investigated carbon aerogels/foams, natural plants and tungsten-based compound systems. The characterization results reveal that the loading of nano Cs0.32WO3 contributes to the partial restoration of π-conjugated structure in rGC, increasing solar absorption and the corresponding thermal energy released by the lattice vibration. Meanwhile, the oxygen vacancies and carrier density of Cs0.32WO3 nanoparticles increase after compositing with rGC, which further enhances the local surface plasma resonances (LSPR) effect. Significantly, the hydrophilic functional groups and excellent wettability of composite aerogel and corn straw play crucial effect in accelerating water transport, activating water molecules and reducing evaporation energy consumption. In a word, the unique construction of rGO-CNTs-Cs0.32WO3 aerogels presents a novel approach for the design of solar-driven freshwater production system, the application expansion of nano tungsten bronze and carbon aerogels.

Novel graphdiyne quantum dots for resistive random access memory

Graphdiyne (GDY), a rising allotropic form of carbon, exhibits a rich variety of electronic, optical and mechanical properties due to the unique π-conjugated structure. However, the processability of GDY into perovskite composites is a vital yet challenging area for further optimized applications. Herein, we synthesized a novel GDY quantum dots (QDs) via Sonogashira cross-coupling reaction between GDY and anthraquinones. The as-prepared GDY QDs show good solubility with perovskite precursor and the GDY QDs doped perovskite was obtained. The GDY QDs based perovskite resistive random access memory device shows reliable resistive switching behaviour with enhanced ON/OFF ratio of ∼103 and long endurance due to the optimized electrode/dielectric interface, which offers opportunities in electronic and optoelectronic fields.

Modification of Covalent Triazine-Based Frameworks for Photocatalytic Hydrogen Generation.

The conversion of solar energy and water to hydrogen via semiconductor photocatalysts is one of the efficient strategies to mitigate the energy and environmental crisis. Conjugated polymeric photocatalysts have advantages over their inorganic counterparts. Their molecular structures, band structures, and electronic properties are easily tunable through molecular engineering to extend their spectral response ranges, improve their quantum efficiencies, and enhance their hydrogen evolution rates. In particular, covalent triazine-based frameworks (CTFs) present a strong potential for solar-driven hydrogen generation due to their large continuous π-conjugated structure, high thermal and chemical stability, and efficient charge transfer and separation capability. Herein, synthesis strategies, functional optimization, and applications in the photocatalytic hydrogen evolution of CTFs since the first investigation are reviewed. Finally, the challenges of hydrogen generation for CTFs are summarized, and the direction of material modifications is proposed.

Pillaring of a conductive polymer in layered V2O5 boosting ultra-fast Zn2+/H+ storage in aqueous media

Aqueous secondary zinc-ion batteries are promising candidates to replace lithium-ion batteries for large-scale energy storage, due to their high safety and low cost. However, the developed cathodes materials are facing low capacity or low cycle life due to sluggish diffusion kinetics. Therefore, the design of a cathode with ultrafast ion diffusion kinetics remains a great challenge. Here, we propose an in-situ intercalation strategy of polypyrrole to improve the cation diffusion kinetics of V2O5. The polypyrrole as a guest significantly enlarges the interlayer spacing, paving the ‘‘superhighway’’ for cation diffusion. In addition, thanks to the unique π-conjugated structure, polypyrrole can shield the electrostatic force of Zn2+ and the host oxygen-sublattice. The energy storage mechanism of the cathode was shown to be a stepwise H+/Zn2+co-intercalation by means of galvanostatic intermittent titration technique (GITT), electrochemical impedance spectroscopy (EIS) and ex situ X-ray diffraction (XRD). Based on the above advantages, the polypyrrole-intercalated V2O5 demonstrates high capacities and excellent cycling performance (220 mA h g−1 after 2000 cycles at 10 A g−1).

Long-Range Intramolecular Spin Coupling through a Redox-Active Bridge upon Stepwise Oxidations: Control and Effect of Metal Ions.

Dinickel(II) and dicopper(II) porphyrin dimers have been constructed in which two metalloporphyrin units are widely separated by a long unconjugated dipyrrole bridge. Two macrocycles are aligned somewhat orthogonally to each other, while oxidation of the bridge generates a fully π-conjugated butterfly-like structure, which, in turn, upon stepwise oxidations by stronger oxidants result in the formation of the corresponding one- and two-electron-oxidized species exhibiting unusual long-range charge/radical delocalization to produce intense absorptions in the near-infrared (NIR) region and electron paramagnetic resonance (EPR) signals of a triplet state due to interaction between the unpaired spins on the Cu(II) ions. Although the two metal centers have a large physical separation through the bridge (more than 16 Å), they share electrons efficiently between them, behaving as a single unit rather than two independent centers. Detailed UV-vis-NIR, electrospray ionization mass spectrometry, IR, variable-temperature magnetic study, and EPR spectroscopic investigations along with X-ray structure determination of unconjugated, conjugated, and one electron-oxidized complexes have been exploited to demonstrate the long-range electronic communication through the bridge. The experimental observations are also supported by density functional theory (DFT) and time-dependent DFT calculations. The present study highlights the crucial roles played by a redox-active bridge and metal in controlling the long-range electronic communication.

Role of π-conjugated-length-regulated perovskite intergrain interconnecting in the photovoltaic performance of perovskite solar cells

Despite great advancements in perovskite solar cells (PSCs), the unsatisfactory intergrain interconnecting in polycrystalline perovskite films remains a challenge to be addressed. Herein, three bilateral dicarboxyic acids, i.e. suberic acid (SA), p-phthalic acid (PTA) and biphenyl dicarboxylic acid (BPDA), are employed as additives to uncover the role of π-conjugated-length-regulated intergrain interconnecting in PSCs. Benefiting from strong interactions between two-sided carboxyl groups and perovskites, incorporation of these additives can control crystal growth, passivate defects/traps and tighten the interconnecting of perovskite grains. Moreover, thanks to the large π-electron delocalization and π-π interactions, introduction of π-conjugated additives (i.e. PTA and BPDA) can evidently intensify the preferred orientation of perovskite crystals and improve the carrier transport between perovskite grains. Especially, by extending π-conjugated structure to biphenyl groups (i.e. BPDA), high-quality perovskite films exhibiting large and ordered grains with vertically columnar alignment, along with strong electrical intergrain interconnecting, are obtained. Moreover, the intrinsic hydrophobicity nature of π-conjugated structures is helpful for improving the moisture stability. Eventually, the champion efficiency of 20.87% is acquired with negligible hysteresis and excellent moisture stability for PSCs with BPDA. Our work demonstrates that the π-conjugated length of additives can play a vital role in regulating the intergrain interconnecting.

Highly efficient separation of ethylene/ethane in microenvironment-modulated microporous polymers

Separation of ethylene (C2H4)/ethane (C2H6) is important yet extremely challenging task in petrochemical industry. Herein, three microporous polymers decorated with phenyls (PAN-P), naphthyls (PAN-NA) and anthryls (PAN-AN) were designed and synthesized in order to systematically study the correlations of the varied π-conjugation structure to the selective adsorptions of C2H6 over C2H4. The adsorption–desorption isotherms of C2H6 and C2H4 in the three polymers are completely reversible at room temperature. Moreover, it is interesting to find that at 298 K, among the three polymers, PAN-AN with the largest π-conjugation anthryl groups exhibits the highest C2H6/C2H4 dynamic selectivity of 2.70. The different adsorption/separation behaviors of C2H6/C2H4 in the three polymers are studied by means of the varied π-conjugation microenvironments as well as the porous characteristics such as specific surface areas, pore volumes and pore sizes and distribution.

A near-infrared fluorescence probe for the detection of bisulfite in vivo and food samples

The evaluation of the HSO3− levels in the biological systems and food samples is of great significance in the understanding its physiological/pathological roles and realizing food security supervision. In this work, a near-infrared (NIR) emitted fluorescence probe (QNP) has been successfully developed to detect HSO3− in live animals and food samples. QNP was designed with a large π-conjugation structure by conjugating of quinolinium with 3H-naphtho[2,1-b]pyran moiety through a reactive C=C double bond. Spectroscopic titration, high resolution mass spectrometry (HR MS), 1H NMR titration and theoretical computation indicates that HSO3− attacks to the C=C double bond through an established 1,4-nucleophilic addition reaction leads to the interruption of the π-conjugation system of QNP, resulting in dramatic decline of the UV–vis absorption and fluorescence spectra. QNP was featured with near infrared emission (centered at 690 nm), high water-solubility (98% water), large Stokes shift (218 nm), perfect selectivity, fast response time (within 50 s) to HSO3−, reliability in broad pH range (6.5–11.5) and low cytotoxicity. The application of QNP in biological systems has been demonstrated by the monitoring of exogenous HSO3− in live adult zebrafish and nude mouse. Furthermore, the evaluation of HSO3− level in several food samples including sugar, white wine, canned fruits and jasmine tea drinks were also determined by fluorescence colorimetric method using QNP.

Electric-Field-Triggered Graphene Production: From Fundamental Energy Applications to Perspectives

ConspectusTwo-dimensional sp2-hybridized graphene has been seriously considered and applied in various fields, such as materials science, energy storage/conversion, catalysis, and biomedicine, on account of its unique long-range-ordered and π-conjugated structure as well as excellent thermal and electric conductivity. At present, the adopted methods for graphene synthesis cover micromechanical exfoliation, epitaxial growth, chemical reduction of graphite oxide, chemical vapor deposition, and liquid-phase exfoliation. Nonetheless, a number of issues and challenges still existed in these employed methods in terms of sustainable and green energy chemistry and environmental friendliness. Electrochemical exfoliation is one of the most promising methods for the large-scale production of graphene by virtue of simple/eco-friendly operation and high-efficiency production. Depending on different exfoliation methods (anodic, cathodic, and dual-electrode) and electrochemical exfoliation conditions such as the reaction device, raw material, electrolyte, and power-supply mode, the exfoliated graphene features various and versatile characteristics. The relatively perfect graphene with intrinsic long-range π-conjugated character is accompanied by the fast capability of electron transfer. The defective graphene features the adjustable size and defect density and tunable amphipathicity. As a result, the corresponding graphene has been employed in energy storage/conversion, biology, and medicine fields. In this Account, we summarize the recent progress in the fundamentals of electrochemical exfoliation to produce the graphene and the derivative exfoliation method and their applications in energy-related fields, and the corresponding perspectives are also highlighted. First, we describe the fundamentals for different exfoliation methods and electric-field-induced effects that can help to guide us to prepare and produce graphene with various properties, covering the size, defect density, and surface chemistry. Subsequently, three electric-field-triggered methods (anodic, cathodic, and dual-electrode exfoliation) are discussed in detail. In particular, the effects of various electrolytes and power-supply modes on electrochemically exfoliated graphene (EEG) are systematically underlined in terms of the exfoliation principles and process, which are the significant factors affecting the structure and properties of EEG and the efficiency of intercalation and exfoliation. In addition, the recent progress in multilevel applications of EEG in energy storage/conversion fields such as supercapacitors, secondary batteries, the oxygen evolution reaction, the hydrogen evolution reaction, the carbon dioxide reduction reaction, and so forth is also summarized. Finally, the expectations and future research directions for the EEG in terms of controllably technological parameters and conditions, precise monitoring and in-depth comprehension of the exfoliation processes, multiscale and diverse products (carbon quantum dots, graphene quantum dots, and single-atom catalysts), and large-scale preparation and application are discussed, which hope to provide significant guidance for future research.

A two-dimensional conductive polymer/V2O5 composite with rapid zinc-ion storage kinetics for high-power aqueous zinc-ion batteries.

Vanadium oxides represent a promising cathode material for aqueous zinc ion batteries (ZIBs) owing to their abundant valences and versatile cation-storage capacities. However, the sluggish Zn2+ diffusion kinetics in the V2O5 framework and poor intrinsic conductivity result in inferior rate capability and unsatisfactory cycling performance of the V2O5 cathode, and thus limits its commercial-scale deployment. Herein, a unique conducting polymer intercalation strategy is developed to optimize the ion/electron transport simultaneously based on the rational design of the composite structure and morphology. The poly(3,4-ethylenedioxythiophene) (PEDOT) intercalated V2O5 not only remarkably enlarges the interlayer distance for facile Zn2+ diffusion, but also diminishes the electron transport resistance by the π-conjugated structure of PEDOT. Additionally, the two-dimensional (2D) morphology enables shorter ion diffusion paths as well as a larger number of exposed sites for Zn2+ insertion. As a result, the PEDOT-intercalated V2O5 (PEDOT/V2O5) exhibits a good high-rate performance (154 mA h g-1 at an ultrahigh current density of 50 A g-1) and a long-term cycling life (maintains 170 mA h g-1 even after 2500 cycles at 30 A g-1). This universal strategy provides a design principle for constructing efficient Zn2+ and electron transport pathways within cathode materials, holding great potential for the development of high-performance and durable ZIB cathodes.

Charge recombination suppression in dye-sensitized solar cells by tuning the dielectric constant of triphenylamine dyes with altering π-bridges from naphthalene to anthracene units.

Charge recombination reactions (CRRs) are responsible for the major loss of power conversion efficiency (PCE) in dye-sensitized solar cells (DSSCs). This study tracks the impact of the dielectric constant (ε') of two D-π-A types of triphenylamine-based organic dyes (TpAzo 1 and TpAzo 2) with naphthalene and anthracene π-bridges on CRRs, respectively, and these dyes are sandwiched as dielectric layers of capacitors between Al electrodes via rf-sputtering deposition. The structure and thickness of components of capacitors were considered by applying field emission scanning electron microscopy (FESEM), and ε', ε'', tan δ, ac conductivity (σac) and electric modulus (M*) of capacitors were analyzed by LCRmetry at different frequencies (f: 102-104 Hz) and temperatures (T: 299-390 K). Cyclic voltammetry (CV) and UV-visible spectroscopy analysis of dyes were performed for revealing the optical profiles, highest occupied molecular orbitals (HOMO), lowest unoccupied molecular orbitals (LUMO), and band gap (Eg); the results were found to be highly consistent with density functional theory (DFT) quantum calculation outputs. The f- and T-dependent relationships were detected for ε', ε'', tan δ and σac, which experienced an upward trend and a downward trend with the increase in T and the decrease in f, respectively. The results indicated higher ε', ε'' M' and M'' values for TpAzo 2 than those of TpAzo 1, which from the molecular point of the view could be related to the more extending π-conjugated structure of anthracene in comparison to naphthalene π-bridges that not only provided appropriate dipole moments and exciton binding energy, but also facilitated powerful intramolecular charge transfer (ICT). Therefore, this study proposes ε', ε'', M' and M'' as novel physiochemical characters in dye design, which have been neglected so far and can open a new synthesis paradigm for developing more efficient organic sensitizers for DSSCs.

A Novel Bionic Flower-Like Z-Scheme Bi4o5i2/G-C3n5 Heterojunction with [[Equation]] / [[Equation]] Active Sites and Π-Conjugated Structure for Increasing Photocatalytic Oxidation of Elemental Mercury

A Novel Bionic Flower-Like Z-Scheme Bi4o5i2/G-C3n5 Heterojunction with [[Equation]] / [[Equation]] Active Sites and Π-Conjugated Structure for Increasing Photocatalytic Oxidation of Elemental Mercury

Graphdiyne-Related Materials in Biomedical Applications and Their Potential in Peripheral Nerve Tissue Engineering.

Graphdiyne (GDY) is a new member of the family of carbon-based nanomaterials with hybridized carbon atoms of sp and sp2, including α, β, γ, and (6,6,12)-GDY, which differ in their percentage of acetylene bonds. The unique structure of GDY provides many attractive features, such as uniformly distributed pores, highly π-conjugated structure, high thermal stability, low toxicity, biodegradability, large specific surface area, tunable electrical conductivity, and remarkable thermal conductivity. Therefore, GDY is widely used in energy storage, catalysis, and energy fields, in addition to biomedical fields, such as biosensing, cancer therapy, drug delivery, radiation protection, and tissue engineering. In this review, we first discuss the synthesis of GDY with different shapes, including nanotubes, nanowires, nanowalls, and nanosheets. Second, we present the research progress in the biomedical field in recent years, along with the biodegradability and biocompatibility of GDY based on the existing literature. Subsequently, we present recent research results on the use of nanomaterials in peripheral nerve regeneration (PNR). Based on the wide application of nanomaterials in PNR and the remarkable properties of GDY, we predict the prospects and current challenges of GDY-based materials for PNR.

Engineering In-Plane Π-Conjugated Structure in Ultrathin G-C3n4 Nanosheets for Enhanced Photocatalytic Reduction Performance

Engineering In-Plane Π-Conjugated Structure in Ultrathin G-C3n4 Nanosheets for Enhanced Photocatalytic Reduction Performance