Showing papers by "Lifeng Yan published in 2022"
TL;DR: The fabrication of highly active and stable Pt-based catalysts is an essential factor for the large-scale development of direct methanol fuel cells (DMFC), which is currently hampered by inefficient metal catalysts as discussed by the authors .
Abstract: The fabrication of highly active and stable Pt-based catalysts is an essential factor for the large-scale development of direct methanol fuel cells (DMFC), which is currently hampered by inefficient metal...
23 citations
TL;DR: In vitro and in vivo experiments revealed that the J-NPs show great NIR-II fluorescence imaging capabilities and anti-tumor effects under 915 nm irradiation and show good stability, considerable photothermal conversion capacity, and excellent resistance to pH, H2O2, and photobleaching.
Abstract: Achieving J-aggregation of a molecule is a fascinating way to construct fluorescent imaging and photothermal therapy agents in the second near-infrared window. Modulation of the balance between intermolecular π-π stacking and steric interactions is an elegant method to acquire J-aggregation dyes. Herein, we succeeded in synthesizing an aza-BODIPY dye with J-aggregation characteristics by introducing steric hindrance (TPA) and a π-bridge (thiophene) in the aza-BODIPY skeleton. In aqueous solutions, supramolecular J-aggregates with a regular lamellar stacking structure could quickly be formed by the dye-templated self-assembly and longer absorption (λmax = 939 nm) and emission (λmax = 1039 nm) bands were observed. After co-assembly of the dye and an amphiphilic polypeptide (POEGMA23-PAsp20), the obtained J-aggregation nanoparticles (J-NPs) with good water solubility and smaller size were more suitable for application in living organisms. In addition, the J-NPs exhibited good stability, considerable photothermal conversion capacity (η = 35.6%), and excellent resistance to pH, H2O2, and photobleaching. In vitro and in vivo experiments revealed that the J-NPs show great NIR-II fluorescence imaging capabilities and anti-tumor effects under 915 nm irradiation (1 W cm-2). This is a rare example of using BODIPY dyes to perform NIR-II fluorescence imaging-guided photothermal therapy under NIR-II irradiation.
16 citations
TL;DR: In this article , the authors developed a robust and stretchable eutectogel electrolyte through a one-step gelation process in situ without introducing additional initiators and cross-linkers.
Abstract: The aqueous zinc-ion hybrid supercapacitor (ZHSC) is a prospective energy storage device for next-generation wearable electronics due to its high safety, low cost, and high energy density. However, the preparation of gel electrolytes reported in the literature is complex and time-consuming, which limits their application in practice. Herein, we developed a robust and stretchable eutectogel electrolyte through a one-step gelation process in situ without introducing additional initiators and cross-linkers. The eutectogel electrolyte consists of ternary deep eutectic solvent (DES) based on Zn(ClO4)2, AM(acrylamide), and H2O, among which ClO4– triggers the free-radical polymerization of AM monomer and Zn2+ cross-links the polymer chains. The prepared Zn-PAM-1 gel exhibits a high ionic conductivity of 51.7 mS cm–1. Due to the inhibition of the free water activity in DES, the voltage window of the constructed flexible ZHSC was extended to 0–2.2 V. Moreover, the ZHSC in situ formed manifests a maximum energy density of 117.5 W h kg–1 at a power density of 833.8 W kg–1 and shows admirable cycling stability, retaining 87.6% of its capacitance after 4000 cycles. In addition, the supercapacitor possesses remarkable temperature stability within a range of −20 to 70 °C. Furthermore, the assembled flexible device illustrates favorable bendability from 0° to 180° without scarifying capacitance, displaying great promise as flexible wearable electronic devices. In summary, such a feasible approach provides further insight into the exploration of innovative eutectogel electrolyte systems for assembling quasi-solid-state pliable high energy storing devices.
12 citations
TL;DR: In this article , LiCl and ZnCl2 were used as hydrogen bond acceptors, while ethylene glycol (EG) was the hydrogen bond donor to prepare DESs, and the as-prepared eutectogels showed high strength, high conductivity and excellent frost resistance.
Abstract: Hydrogels have received extensive attention due to their flexibility and conductivity. However, hydrogels often cannot achieve high conductivity and high mechanical strength at the same time, and the working temperature is also limited due to water as the solvent. Deep eutectic solvents (DESs) are regarded as one kind of green solvent due to their good stability, biocompatibility, and conductivity. The eutectogel prepared with DESs as the solvent has also attracted attention. In this work, LiCl and ZnCl2 were used as the hydrogen bond acceptors, while ethylene glycol (EG) was the hydrogen bond donor to prepare DESs. Poly(vinyl alcohol) (PVA) was then dissolved in DES to form eutectogel via the multihydrogen bonds among the components and coordinate bond between the metal ion and PVA molecules. The as-prepared eutectogels showed high strength, high conductivity, and excellent frost resistance. Interestingly, by introducing lignin, the mechanical properties of the eutectogel have been greatly improved. The maximum mechanical strength was 4.8 MPa with the elongation at break of 550%, the conductivity of 19.7 mS cm–1 could be reached at room temperature, and it could be stable for one month at −20 °C, which contributed to the lignin enhancement due to its multifunctional groups and interactions with the other components. Similarly, glycerol can also enhanced the performance of the eutectogels by controlling the crystalline of PVA chains in domains. Moreover, the prepared gel proved a huge application potential in flexible sensing.
9 citations
TL;DR: In this article , a 3D Ni/NiO/RG composite was proposed for methanol oxidation reaction (MOR) in alkaline solution, which not only bears abundant accessible active sites but also improves the energetics of MOR.
9 citations
8 citations
TL;DR: In this paper , the formation of J-aggregates in terms of intermolecular interactions is discussed and summarized for NIR imaging and phototherapy, to provide a clear direction and reference for designing Jaggregated organic dyes to better enable biological applications.
Abstract: With the continuous development of organic materials for optoelectronic devices and biological applications, J-aggregation has attracted a great deal of interest in both dye chemistry and supramolecular chemistry. Except for the characteristic red-shifted absorption and emission, such ordered head-to-tail stacked structures may be accompanied by special properties such as enhanced absorption, narrowed spectral bandwidth, improved photothermal and photodynamic properties, aggregation-induced emission enhancement (AIEE) phenomenon, and so forth. These excellent properties add great potential to J-aggregates for optical imaging and phototherapy in the near-infrared (NIR) region. Despite decades of development, the challenge of rationally designing the molecular structure to adjust intermolecular forces to induce J-aggregation of organic dyes remains significant. In this review, we discuss the formation of J-aggregates in terms of intermolecular interactions and summarize some recent studies on J-aggregation dyes for NIR imaging and phototherapy, to provide a clear direction and reference for designing J-aggregates of near-infrared organic dyes to better enable biological applications. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.
7 citations
TL;DR: A novel NIR-II small-molecule D-A type organic fluorophore conjugation of triphenylamine, thiophene, and benzo[c,d] indol groups (TPA-Et) with strong electron-donating and accepting groups has been synthesized as discussed by the authors .
7 citations
TL;DR: In this paper , a Br-and piperazine-modified cyanine dye (FN) and its nanomicelles encapsulated by an amphiphilic polypeptide with sidechains of tertiary amine (PEA) were formed by the self-assembly of FN and PEA.
6 citations
TL;DR: Gels have gained much attention in flexible batteries as mentioned in this paper , but traditional hydrogel electrolytes are insufficient to solve the fundamental problems of zinc cathode, such as dendrite issues and parasitic side reactions.
Abstract: Gels have gained much attention in flexible batteries. However, traditional hydrogel electrolytes are insufficient to solve the fundamental problems of zinc cathode, such as dendrite issues and parasitic side reactions,...
5 citations
TL;DR: In this paper , a poly(aspartic acid) polypeptide with amide links in the backbone and nitroxide radical pendant groups in the side chains was successfully synthesized via modifying the polyPEptides with 4-amino-2,2,6,6-6-tetramethylpiperidine.
Abstract: The rapidly growing demand for batteries has led to the lack of global mineral resources and rechargeable organic batteries are paid extensive attention due to the advantages of organic electrodes of abundance in resource, being lightweight, and high flexibility. However, mostly organic electrodes utilizing the aliphatic backbones were non-degradable, leading to unsustainability when the active sites fail. Herein, a poly(aspartic acid) polypeptide with amide links in the backbone and nitroxide radical pendant groups in the side chains was successfully synthesized via modifying the polypeptides with 4-amino-2,2,6,6-tetramethylpiperidine. In combination with the Zn anode, the PASP-Tempo composite electrode exhibited rapid charging/discharging and superior cyclic stability with reversible two-electron redox reaction in an aqueous electrolyte. The Zn/PASP-Tempo organic radical battery delivered a discharge capacity of ~80 by two-electron reaction and charge/discharge rates of up to 18 . Because the redox reaction process of the nitroxyl radical turning into oxoammonium was a p-type mechanism that interacts with an anion, three electrolytes with different anions were conducted in the Zn/PASP-Tempo organic radical battery. Experimental results indicated that discharge plateau voltage was tunable by choosing different zinc salts as electrolytes. And it was found that the capacity retention of up to 97.4% after 500 cycles was realized in 1m ZnClO 4 electrolyte which can be attributed to the adjacent reaction potentials of the two-step one-electron reaction.
TL;DR: In this paper , the authors designed a water/glycerol binary solvent coordinating the hydrophilic polymers to reconstruct the water molecules' environment in the hydrogel, which achieved a 3.0 kPa interface adhesion strength between Zn and the hyrogel.
TL;DR: In this article , a nano-Graphene oxide (GO) nanosheets reinforced by carbon black (CB) was synthesized through the condensation of the tetraethoxysilane (TEOS) and (3-Mercaptopropyl)trimethoxyldimethyltrie-silicon (MPTS) monomer.
TL;DR: In this article, an electrochemical method for preparing graphene at both the anode and cathode simultaneously was proposed, where graphite was first subjected to ion intercalation sufficiently on the anodes and cathodes and then expanded ultrafast under the assistance of microwave irradiation.
TL;DR: In this article , a polyethylene glycol conjugated and disulfide-modified macromolecule fluorophore (MPSS) was designed and synthesized for photothermal therapy.
TL;DR: In this article , a high-strength PVA-based eutectogel has been synthesized by a strategy of solvent-induced micro-phase separation, which is capable of detecting the bending movement of joints and identifying the different bending angles of fingers.
Abstract: A high-strength PVA-based eutectogel has been synthesized by a strategy of solvent-induced microphase separation. Here, PVA was dissolved in water, and green solvent DES (choline chloride/glycerol) was introduced to induce PVA to undergo microphase separation, leading to poorly solvated domains and highly solvated domains. In poorly solvated domains, the PVA chains were folded and crystallized, and the formed crystalline domains served as physical cross-linkers. Such cross-linking structures endowed the eutectogels with remarkable mechanical properties, showing strength in tension reaching up to 1.2 MPa and elongation at a break of 405%, with rupture toughness of 3.23 MJ m-3. Meanwhile, the as-obtained eutectogel possessed reprocessability and could be recycled through high-temperature dissolution and recasting. In addition, the eutectogel also exhibited excellent frost resistance, and its ionic conductivity could still reach 0.62 mS cm-1 at -40 °C. In addition, the eutectogel can maintain a stable output signal during a multiple strain cycle, showing the potential application in the flexible sensor. The eutectogel is capable of detecting the bending movement of joints and identifying the different bending angles of fingers, showing a certain applied potential in motion detection of the human body.
TL;DR: Based on the effective accumulation of tumor sites and considerable PCE (>40%), P-ipr@Gal nanoparticles have a lower background and higher tumor background ratio, which makes them a potential NIR-II imaging-guided photothermal therapy agents.
Abstract: Through the activation of packing arrangements of dyes to modulate their photophysical and/or photochemical properties, not only new NIR-II dyes but tumor-specific NIR-II imaging and therapy can also be achieved. Herein, we designed an acid-responsive polypeptide nanoparticle (P-ipr@Gal) encapsulated with a pH-sensitive amphiphilic polypeptide (P-ipr) as a carrier for the galactose-conjugated BODIPY (Gal-BDP) dye. When P-ipr@Gal NPs are enriched in tumor regions by the EPR effect, the acidic microenvironment (pH 6.4-6.8) promotes the disintegration of P-ipr@Gal nanomicelles and the release of sufficient Gal-BDP. The protonation of the julolidine nitrogen of the Gal-BDP dye switched on the molecular stacking transformation from the H-aggregate to J-aggregate. The J-aggregate significantly enhanced the redshift absorption and emission intensity, which enhanced the fluorescence brightness and photothermal therapeutic effect in the tumor region. We also prepared J-aggregates PAsp@Gal with non-acidic responsive polyaspartic acid benzyl esters (PAsp) encapsulated Gal-BDP, which remained "always-on" with J-aggregate characteristics. The P-ipr@Gal (or PAsp@Gal) J-aggregate has a maximum emission peak redshifted to nearly 1064 nm, with a 3.5-fold increase in the emission intensity compared to the H-aggregate at pH 7.4. Based on the effective accumulation of tumor sites and considerable PCE (>40%), P-ipr@Gal nanoparticles have a lower background and higher tumor background ratio, which makes them a potential NIR-II imaging-guided photothermal therapy agents.
TL;DR: In this article , a palladium nanoparticles with a size of 2-36 nm were uniformly distributed over the Silanized graphene oxide (SGO) matrix, and polymethylvinylsiloxane can be cured to silicone rubber (SR) by B2O3.
Abstract: Hydrogen is a dangerous gas because it reacts very easily with oxygen to explode, and the accumulation of hydrogen in confined spaces is a safety hazard. Composites consisting of polymers and catalysts are a common getter, where the commonly used catalyst is usually commercial Pd/C. However, it often shows poor compatibility with polymers, making it difficult to form a homogeneous and stable composite. In this work, palladium chloride (PdCl2) was converted to palladium (Pd) nanoparticles by reduction reaction and supported on graphene oxide (GO) modified by silanization. Spherical Pd nanoparticles with a size of 2–36 nm were uniformly distributed over the Silanized graphene oxide (SGO) matrix. When mixed with Pd/SGO, polymethylvinylsiloxane can be cured to silicone rubber (SR) by B2O3. Afterwards, the vinyl in the polymer can interact with hydrogen under the catalysis of Pd through the addition reaction, thus achieving the purpose of hydrogen elimination. The polymer elastomers with excellent self-healing properties and improved hydrogen elimination performance were prepared and were superior to the commercial Pd/C. In addition, excellent environmental adaptability was also demonstrated. The new getter SR-Pd/SGO provides a new avenue for developing polymer getters with superior properties.