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Bacterial infections in wounds significantly impair the healing process. The use of natural antibacterial products over synthetic antibiotics has emerged as a new trend to address antimicrobial resistance. An ideal tissue engineering scaffold to treat infected wounds should possess antibacterial properties, while simultaneously promoting tissue regrowth. Synthesis of hydrogel scaffolds with antibacterial properties using hemp shive (HT1/HT2) lignin, sugarcane bagasse (SCB) lignin and cellulose was carried out. All lignin samples had low molecular weights and were constituted of G-type β-5 dimers, linked by β-O-4 bonds, as determined by MALDI-TOF-MS. Hemp lignin was more cytotoxic to mouse fibroblasts (L929) compared to SCB lignin. All lignin samples demonstrated antibacterial properties against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis, with greater efficiency against Gram-negative strains. 3D hydrogels were engineered by crosslinking SCB lignin with SCB cellulose in varying weight ratios in the presence of epichlorohydrin. The stiffness of the hydrogels could be tailored by varying the lignin concentration. All hydrogels were biocompatible; however, better fibroblast adhesion was observed on the blended hydrogels compared to the 100% cellulose hydrogel, with the cellulose : lignin 70 : 30 hydrogel showing the highest L929 proliferation and best antibacterial properties with a 24-hour bacterial growth reduction ranging from 30.8 to 57.3%. [ABSTRACT FROM AUTHOR]

A novel dual-outward contraction mechanism is applied to construct 2D hollow carbon superstructures (HCSs) via pyrolysis of hybrid ZIF superstructures. One outward contraction stress is offered by the in situ formed thin carbon shell, while another originates from the interconnected facets of ZIF polyhedra within the ZIF superstructure. [ABSTRACT FROM AUTHOR]

Metallo-helicoids are constructed by intermolecular coordination interactions between covalent linear polymer and tritopic/hexatopic molecular templates. These metallo-polymers with helicoidal conformation exhibit high antimicrobial activities against both Gram-positive and Gram-negative pathogens. [ABSTRACT FROM AUTHOR]

We report a synergetic dual-metal single-atom (Pd and Ni) promoting approach that modulates the catalytic activity and selectivity of α-MnO2 toward HMF oxidation. Pd and Ni have different spatial doping profiles and catalytic functions. Pd single atoms are embedded in the crystalline lattice of α-MnO2, which activates lattice oxygen and creates abundant oxygen vacancies. Ni single atoms that are mainly anchored on the surface of α-MnO2 improve the ability to dissociate molecular oxygen for healing oxygen vacancies. Pd and Ni work synergistically to accelerate the consumption and recovery of active lattice oxygen during HMF oxidation, which results in 3 fold enhancement of productivity and near-unity DFF selectivity. Ex situ and in situ characterization together with theoretical calculations confirm the pronounced effects of Pd and Ni on oxygen species. Compared to conventional single atom catalysts requiring a metal loading of 1–10 wt%, a single atom promoter requiring a tiny metal loading <0.5 wt% allows one to significantly improve the activity of α-MnO2. [ABSTRACT FROM AUTHOR]

Three tris-bis(urea) ligands with triphenylamine-based C3-symmetric spacers were synthesized, which assembled with sulfate or phosphate to form anionic A3L2 pinwheel helices (A = anion and L = ligand) and A4L4 tetrahedra, respectively. Interestingly, narcissistic self-sorting was observed in both structures from the mixture of the ligands, wherein each assembly contains only one type of ligand with no detectable mixed-ligand product as confirmed by the NMR and MS studies. [ABSTRACT FROM AUTHOR]

In order to clarify the research status, hot spots and development trend in the field of conversion of carbon dioxide, a large amount of literature data set in the scientific network database was analyzed by bibliometrics. Through the statistical analysis of the publication data, it is observed that China's publishing industry has entered a rapid development stage: the comprehensive strength ranks the first in the world, the volume of publications is the largest, and the influence is also greater. The most productive journal and institution are Applied Catalysis B-Environmental and Chinese Academy of Sciences. In addition, the research status and problems of the photocatalytic conversion of carbon dioxide are briefly introduced. Finally, according to the analysis results and the existing problems, the future development of photocatalytic CO2 conversion is underway. [ABSTRACT FROM AUTHOR]

A great challenge in catalyst engineering is precisely assembling and positioning nanoscale active metals at desired locations while constructing robust functional architectures. This article presents a novel approach for constructing macroscopic Ag-doped manganese oxide aerogels (up to 2 L) while homogeneously incorporating active Pt single atoms (Pt/Ag-MnO2) based on a solution–solid–solid (SSS) mechanism. AgOx seeds were identified as key species for triggering the octopus-like growth of MnO2 nanofibers and inserting Ag and Pt into the MnO2 crystalline framework. The interconnection and entanglement among nanofibers allowed the formation of mechanically strengthened hierarchical structures, leading to one of the most robust manganese-based aerogels to date. Impressively, the Pt/Ag-MnO2 aerogel also possessed promising selectivity and stability toward the electrocatalytic oxygen reduction reaction, with Pt showing a high mass activity of 1.6 A/(mgPt) at 0.9 V vs. RHE. Experimental characterization and theoretical calculation confirmed Pt single atoms to be located at substitutional lattice sites, which reduced the overall oxygen reduction barriers. Our approach suggests that SSS or other analogous nanofiber or nanowire growth strategies are powerful in controlling structural formation over the entire range of length scales while being applicable to fabricating single-atom catalysts. [ABSTRACT FROM AUTHOR]

This work demonstrates a self-assembling peptide strategy to form finite, molecularly defined trigonal bipyramidal-like hexamers which offer control over multivalent ligand display for enhanced tumor targeting. [ABSTRACT FROM AUTHOR]

Disodium ethylenediamine tetraacetate (Na2EDTA) is a commonly used reagent in laboratory, which has high oxygen and nitrogen content. In this study, Na2EDTA was employed as a precursor to fabricate porous carbon (PC) materials through a one-step pyrolysis process at different temperatures (650 and 750 °C). The obtained PC samples were systematically characterized and employed as adsorbents for methylene blue (MB) adsorption by batch experiments. The results showed that the PC samples possessed satisfying specific surface area and pore volume through the direct one-step pyrolysis process and a higher pyrolysis temperature (750 °C) favored the formation of mesopores. The formation of the pore structure can be attributed to the existence of a large amount of alkaline functional groups in Na2EDTA, which exhibited a pore-making effect during the pyrolysis process. Adsorption experiments indicated that MB binding onto the PC samples obeyed the pseudo-second-order kinetic model and Langmuir isotherm model. The maximum adsorption capacities calculated using the Langmuir model were 734.4 and 1354.7 mg g−1 for PC650 and PC750, respectively, which are comparable to or much higher than those of most of the adsorbents reported recently. Furthermore, the PC sample exhibited extensive adsorption performance for other dyes including cation and anion dyes. In addition, the carbon materials can be regenerated with ethanol and still maintained high adsorption performance even after 4 regeneration cycles, indicating superior recyclability. This study provided a simple one-step pyrolysis method to prepare porous carbon materials through self-activation effects. [ABSTRACT FROM AUTHOR]

The synergy among twelve carboxylates from two hexavalent baskets 16− assisted the encapsulation of one divalent diammonium guest 32+–62+ and the formation of ternary [3–6⊂12]10−. The reduction of basket's multivalency, by photoinduced α-decarboxylation of 16− to give 23−, intercepted the interannular cooperativity operating in the stabilization of capsulpex [3–6⊂12]10− to dramatically diminish the binding affinity towards diammonium guests. As a result, the cationic guests were released into bulk water with 23− assembling into nanoparticles. With numerous drugs carrying positive sites, the finding reported here could now be examined for their light-promoted spatiotemporal delivery. [ABSTRACT FROM AUTHOR]

A new heterometallic macrocycle with photochromic properties was succesfully constructed through coordination-driven self-assembly, which features interesting photoswitchable Förster resonance energy transfer (FRET) behaviour. [ABSTRACT FROM AUTHOR]

Here we report for the first time a Pd-MnO2 catalyst with a single-atom feature that can convert 5-hydroxylmethyfurfural (HMF) into the important bioplastic building block 2,5-furandicarboxylic acid (FDCA) with a high yield of 88% in aqueous solution using O2 as an oxidant at ambient pressure. Pd-MnO2 shows higher activity in the productivity of FDCA (100.91 mmol h−1 gPd−1) than its Pd nanoparticle counterpart (45.57 mmol h−1 gPd−1) and state-of-the-art Pd-based catalysts. Pd-MnO2 displays promising recyclability with no degradation after five catalytic runs. Experimental and theoretical results suggest that the single-atom Pd sites that have enhanced binding affinity to HMF and their surrounding sites on the MnO2 support work synergistically toward HMF oxidation. [ABSTRACT FROM AUTHOR]

Advancement of electrocatalysts relies on the construction of both a highly efficient catalytic center and a highly conductive network support. Herein, we prepared a 3D interwoven structure with Pd atoms deposited on homogeneously bound MnO2 nanowires and carbon nanotubes (CNTs) (Pd/MnO2–CNT), allowing the combination of superior catalytic performance of atomic Pd incorporated in the metal oxide and the high conductivity of CNT. Using this nanocomposite, stable bifunctional oxygen reduction/evolution reaction (ORR/OER) was achieved. Pd/MnO2–CNT displayed a large Pd mass activity for ORR, which is two magnitudes higher than that of Pd/CNT and 5-fold higher than that of the state-of-the-art Pd-based electrocatalysts operated in alkaline medium. Application of this composite catalyst in Zn–air batteries generates significantly high efficiency and cycling stability. Experimental and theoretical studies revealed that MnO2 provided stronger electronic metal–support interaction than CNT. Pd single atoms doped in MnO2 work synergistically with the surrounding metal sites to activate molecular oxygen, and display optimized binding strength to reaction intermediates. Our strategy can be generalized to design new single atom electrocatalysts for numerous functionalities. [ABSTRACT FROM AUTHOR]

Host–guest complexation based on terpyridine (tpy) three-dimensional (3D) metallo-cages has received less attention due to the complicated structure and solubility issues. Herein, a three-armed metallo-organic ligand (L) was synthesized via three 120°-bent bis-tpy groups as a rigid tetrakis-tpy core, which possesses one benzo-21-crown-7 (B21C7) for further host–guest interaction. The metallo-organic cages [M3L2] with molecular weights up to 13 000 Da and giant cavities were prepared in near-quantitative yield by self-assembly of L with metal ions, such as Zn2+ and Fe2+. The 3D metallo-supramolecules were characterized and their formation was supported by NMR, DOSY, ESI-MS and TEM. Hosts [M3L2] were threaded through a difunctional alkylammonium salt by host–guest interactions to polymerize, and subsequently generate novel metallo-gels between [Zn3L2] and bis-ammonium salt (N2). [ABSTRACT FROM AUTHOR]

A set of self-assembled tri- and tetrapodal metal coordination cage structures (cage-1 and cage-2, respectively) constructed from the uranyl dication (UO22+) and a dibenzoic acid functionalised cis-calix[4]pyrrole (1) are described. The inherent photochemical reactivity of the uranyl dication mediates the transformation of cage-1 to cage-2via the activation of molecular oxygen. [ABSTRACT FROM AUTHOR]

In this study, hollow cube-like CuS composites derived from Cu2O crystals were synthesized via a simple one-step reaction. The formation of hollow cavities can be explained through the Kirkendall-based process. The morphologies and electromagnetic absorption (EA) properties of the CuS were measured and investigated. A sample with 35 wt% hollow CuS loading paraffin-composite achieves an optimal reflection loss (RL) of −63.99 dB at 12.09 GHz under the thickness of 2.25 mm. Simultaneously, the effective EA bandwidth (RL ≤−10 dB) can be tuned between 4.63 and 18.00 GHz by changing the thickness of the absorber from 1.5 mm to 4.0 mm. The excellent EA performance is attributed to the high dielectric loss, appropriate impedance matching and multiple reflections induced by the unique hollow cube-like structure. Thus the hollow cube-like CuS is expected to be a promising material in approaching for microwave absorption against the electromagnetic pollution. [ABSTRACT FROM AUTHOR]

Using a novel dynamic covalent approach relying on reversible hydrazone formation, a purely organic 3-dimensional prismatic cage was developed in water at elevated temperatures. By lowering the temperature, the hydrazone bond becomes kinetically inert. This self-assembled cage acts as an effective receptor for donor–acceptor pairs, whose interactions are weak in the absence of the cage. [ABSTRACT FROM AUTHOR]

We present the successful construction of a new family of organometallic rotaxane-terminated dendrimers using neutral platinum–acetylides as the main scaffold. The fourth generation dendrimer has 24 rotaxane moieties on the surface termini in a monodisperse manner. [ABSTRACT FROM AUTHOR]

This article presents a new strategy to engage coordination-driven self-assembly for platinum drug delivery. The self-assembled supramolecular hexagon is conjugated with three equivalents of Pt(iv) prodrugs and displays a superior therapeutic index compared to cisplatin against a panel of human cancer cell lines. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate a “three birds one stone” strategy for preparing 1D N-doped porous carbon nanotubes embedded with core–shell Co@CoOx nanoparticles (Co@CoOx/NCNTs) from bimetallic ZnO@Zn/Co-ZIF nanowires. The ZnO nanowires played three roles: (i) ZnO acted as a template for 1D metal–organic framework (MOF) growth, (ii) in situ evaporation of Zn during pyrolysis prevented the aggregation of the carbon framework and benefited the formation of hierarchical pores, and (iii) the excess oxygen species released from ZnO in situ reacted with metallic cobalt nanoparticles during pyrolysis, leading to the configuration of a Co@CoOx core–shell structure. The as-prepared 1D Co@CoOx/NCNTs exhibited excellent oxygen reduction reaction performance, including a high kinetic current (4.6 times better compared to 20 wt% Pt/C at 0.7 V), a low Tafel slope of 80 mV dec−1, outstanding stability, and strong tolerance to CH3OH crossover. The assembled Zn–air batteries with Co@CoOx/NCNTs yielded high open-circuit voltage (1.52 V), superior stability (over 100 h of operation), and unprecedented rate performance that ranged from 1 to 500 mA cm−2, while existing batteries have never achieved a galvanostatic discharge current density larger than 300 mA cm−2. Such exceptional rate capability was ascribed to the formation of a uniform interconnected nanotube network, facilitated electron transport, and an enlarged electrochemically accessible surface area in the unique 1D porous tubular structure. [ABSTRACT FROM AUTHOR]

A novel S-heterocyclic annulated perylene diimide (SPDI) derivative connected to two polyhedral oligosilsesquioxane (POSS) nanoparticles was designed and synthesized to reveal the effect of bulky substituent groups on its self-assembly behavior and photoluminescence properties. This featured organic–inorganic hybrid can easily self-assemble into crystalline microbelts with a length of several hundred micrometers. The phase behavior and crystal structure of the compound was then elucidated via a combination of different experimental techniques such as differential scanning calorimetry (DSC), one- and two-dimensional (1D and 2D) X-ray diffraction (XRD), UV/Vis and fluorescence spectra, and tandem mass spectrometry with traveling wave ion mobility separation. The experimental results reveal that the compound has a strong propensity to form a dimer in solution and possesses unique molecular packing of discrete dimeric motifs in the solid state. Moreover, due to this discrete molecular packing behavior, the compound exhibits enhanced photoluminescence properties both in solution and in the solid state compared to the reference compound SPDI without a pendant POSS cage. In addition, based on the dual reactions of electron transfer and fluoride-triggered Si–O bond cleavage, the POSS containing SPDI exhibits higher selectivity and sensitivity to fluoride anions, and a quicker response against the reference SPDI without a pendant POSS cage. The enhanced luminescence properties, and the ability to form ultralong crystalline microbelts, in combination with the rapid selective response for F− make this compound a promising material for the fabrication of luminescent devices and colorimetric chemosensors. [ABSTRACT FROM AUTHOR]

A heterobinuclear complexation strategy on homoditopic pillar[5]arene was developed by using a pillar[5]arene with two rims decorated with benzaldehyde oximes. The unique selective recognition process was found to result from vesicular formation based on a controllable self-assembly, leading to binding of thorium(iv) only onto one rim, with the other rim being unoccupied for subsequent complexation of a second different metal ion. [ABSTRACT FROM AUTHOR]