Porous tremella-like NiMoP/CoP network electrodes as an efficient electrocatalyst.

The design of efficient, stable and cost-effective electrocatalysts for the hydrogen evolution reaction holds substantial significance in water electrolysis, but it remains challenging. Tremella-like nickel-molybdenum bimetal phosphide encapsulated cobalt phosphide (NiMoP/CoP) with hierarchical architectures has been effectively synthesized on nickel foam (NF) via a straightforward hydrothermal followed by low-temperature phosphating method. Based on the unique structural benefits, it significantly increases the number of redox active centers, enhances the electrical conductivity of materials, and diminishes the ion diffusion path lengths, thereby promoting efficient electrolyte penetration and reducing the inherent resistance. The as-obtained NiMoP/CoP/NF electrocatalyst exhibited remarkable catalytic activity with an ultralow overpotential of 38 mV (10 mA cm-2) and low Tafel slope of 83 mV dec-1. The straightforward synthesis process and exceptional electrocatalytic properties of NiMoP/CoP/NF demonstrate great potential for the HER to replace the precious metal catalyst.

One-pot self-assembled bimetallic sulfide particle cluster-supported three-dimensional graphene aerogel as an efficient electrocatalyst for the oxygen evolution reaction.

The preparation of an electrocatalyst for the oxygen evolution reaction (OER) with high catalytic activity, good long-term durability and rapid reaction kinetics through interface engineering is of great significance. Herein, we have developed a bimetallic sulfide particle cluster-supported three-dimensional graphene aerogel (FeNiS@GA), which serves as an efficient electrocatalyst for OER, by a one-step hydrothermal method. Profiting from the synergy of the FeNiS particle cluster with high capacitance and GA with its three-dimensional porous nanostructure, FeNiS@GA shows a high specific surface area, large pore volume, low contact resistance, and decreases the electron and ion transport routes. FeNiS@GA exhibits outstanding OER activity (when the current density is 50 mA cm-2, the overpotential is 341 mV), low Tafel slope (63.87 mV dec-1) and remarkable stability in alkaline solutions, outperforming FeNiS, NiS@GA, FeS@GA and RuO2. Due to its simple synthesis process and excellent electrocatalytic performance, FeNiS@GA shows great potential to replace noble metal-based catalysts in practical applications.

Polysulfide induced synthesis of a MoS2 self-supporting electrode with wide-layer-spacing for efficient electrocatalytic water splitting.

Efficient non-noble metal bifunctional electrocatalysts can increase the conversion rate of electric energy in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Herein, a ball & sheet MoS2/Ni3S2 composite with wide-layer-spacing and high 1T-rich MoS2 is assembled on nickel foam (NF) via a two-step solvothermal method with polymeric sulfur (S-r-DIB) as the sulfur source. The obtained material serves as both the cathode and the anode toward overall water splitting in an alkaline electrolyte. The results proved that the interpenetration of MoS2/Ni3S2-p with a ball and sheet structure increased the material active surface area and exposed more catalytic active sites, which contributed to the penetration of solution and the transfer of charge/hydrion. Meanwhile, two different semiconductors of MoS2 and Ni3S2 along with the presence of ample active sulfur edge sites and few-layer, wide-layer-spacing structures of MoS2 lead to an outstanding electrocatalytic activity. In particular, the electrodes of MoS2/Ni3S2-p only need a battery voltage of 1.55 V at 10 mA cm-2. The bifunctional electrocatalyst MoS2/Ni3S2-p also shows excellent stability at large current densities during the electrochemical test.

Nanostructured polyvinylpyrrolidone-curcumin conjugates allowed for kidney-targeted treatment of cisplatin induced acute kidney injury.

Acute kidney injury (AKI) leads to unacceptably high mortality due to difficulties in timely intervention and less efficient renal delivery of therapeutic drugs. Here, a series of polyvinylpyrrolidone (PVP)-curcumin nanoparticles (PCurNP) are designed to meet the renal excretion threshold (∼45 kDa), presenting a controllable delivery nanosystem for kidney targeting. Renal accumulation of the relatively small nanoparticles, 89Zr-PCurNP M10 with the diameter between 5 and 8 nm, is found to be 1.7 times and 1.8 times higher than the accumulation of 89Zr-PCurNP M29 (20-50 nm) and M40 (20-50 nm) as revealed by PET imaging. Furthermore, serum creatinine analysis, kidney tissues histology, and tubular injury scores revealed that PCurNP M10 efficiently treated cisplatin-induced AKI. Herein, PCurNP offers a novel and simple strategy for precise PET image-guided drug delivery of renal protective materials.

Detailed formation process of Co@C catalysts and the influence of structural regulation on catalytic properties.

Co@C is a novel class of catalysts with many structural advantages, such as highly dispersed active species, developed pore structure, and special encapsulated structure. Although considerable progress has been made in the development of new Co@C materials, research on the formation mechanism of these materials is lacking. Herein, the overall microcosmic structure of the Co@C catalyst was investigated by systematic characterization. Subsequently, a pseudo in situ method was employed to explore the detailed structure of the Co@C catalyst pyrolyzed at different temperatures. The special carbon environment of materials is essential for synthesizing materials during pyrolysis at high temperatures. Co ions were reduced to Co0 by the surrounding carbon atoms at a high temperature. In return, the surrounding carbon atoms were catalyzed by Co0 particles to form carbon nanotubes. However, with the obstruction of amorphous carbon atoms that are not in contact with Co0, the paths through which the carbon nanotubes move forward formed the porous structure of the catalyst, as well as the graphitic encapsulated structure. Further, the effects of pretreatment conditions on the structure and properties of the Co@C catalyst were studied systematically.

Concomitant induction to few-layer and 1T-rich two-dimensional MoS2 by rigid segment-containing polysulfide as a sulfur source and in situ intercalator.

Few-layer and 1T-rich MoS2 is synthesized by a one-step solvothermal process using a rigid segment-containing polysulfide as a concomitant sulfur source and in situ intercalator. The prepared MoS2 displays superior hydrogen evolution reaction activity, providing a facile and mild approach for the development of high performing MoS2 and other two-dimensional lamellar materials.

High topological tri-metal phosphide of CoP@FeNiP toward enhanced activities in oxygen evolution reaction.

The development of non-precious metal electrocatalysts with high activity, good durability and low cost to replace precious metal electrocatalysts is highly demanded for oxygen evolution reaction (OER). However, the higher overpotential, less catalytic sites and lower catalytic rate of precious metal electrocatalysts affect their practical application, which needs to be optimized from the aspects of structural design (e.g., specific morphology/particle size, geometric/electronic structures). In this study, we reported a high topological tri-metal phosphide of CoP@FeNiP derived from the composite structure of ZIF-67 twined on a FeNi-LDH shelled with ultrathin carbon networks (ZIF-67/FeNi-LDH) grown on a nickel foam. In the synthesis process of FeNi-LDH, the addition of polyvinylpyrrolidone (PVP) promoted the self-assembly of the topological structure of FeNi-LDH and further nucleation of the topological structure of the ZIF-67 precursor on FeNi-LDH. Besides, CoP@FeNiP inherits the topological structure of ZIF-67/FeNi-LDH. The obtained CoP@FeNiP/NF shows superior OER performance with a low overpotential of ∼283 mV at 100 mA cm-2, a low Tafel slope of ∼31.8 mV dec-1 and a conservation rate of catalytic activity of ∼98% after 110 h of continuous electrolysis at 10 mA cm-2. The remarkable activity of CoP@FeNiP/NF can be attributed to its unique structural features, such as the hierarchical morphology, large surface area, ultrathin carbon networks and the feature of phosphide, all of which simultaneously promote the OER process. The extraordinary catalytic activities and stability of CoP@FeNiP/NF are significant to meet the industrial requirements for bulk water electrocatalysis.

A new solvate of clonixin and a comparison of the two clonixin solvates.

A new solvate of clonixin (CLX), a dimethylacetamide (DMA) solvate, has been obtained by crystal growth in DMA. The new form was characterized by NMR, single-crystal X-ray diffraction, and PXRD. The crystal structure is stabilized by a strong hydrogen bond between the carboxylic acid OH of CLX and the DMA carbonyl, the strength of which is on par with those of the four solvent-free forms of CLX and the DMF solvate. These previously known forms are based on either the acid-acid homosynthon or the acid-pyridine heterosynthon, depending on the dihedral angle between the two aromatic rings of CLX, or the heterodimer between CLX and DMF. The new solvate loses DMA to convert into form I of CLX, as confirmed by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD), similar to how the DMF solvate does. A comparison of the two solvates was carried out and theoretical studies were performed to shed light on the conformational difference between the two CLX molecules in the two solvates and the packing differences between them. The insight gained on this solvatomorphic system could aid the design of new solvates and cocrystals of CLX.

N-doped carbon-coated ultrasmall Nb2O5 nanocomposite with excellent long cyclability for sodium storage.

Niobium pentoxide (Nb2O5) has drawn significant interest as a promising anode for sodium ion batteries (SIBs) due to its large interplanar lattice spacing and relatively high diffusion efficiency. However, the intrinsic drawbacks of low electrical conductivity and substantial volume change greatly impede its practical applications in large-scale energy storage systems. In this work, ultrasmall Nb2O5 nanoparticles wrapped with nitrogen-doped carbon (denoted as Nb2O5@NC) were delicately synthesized via a facile sol-gel method and subsequent heat treatment. The unique structure of ultrasmall Nb2O5 nanoparticles in a carbonaceous matrix can not only effectively shorten the transmission distance for both ions/electrons but also relieve the strain and stress caused by volume variation during the sodiation/desodiation process. In addition, the synergistic effect of nitrogen doping and carbon coating can further improve the electronic conductivity and pseudocapacitive behavior of the active materials, thus promoting the rapid electrochemical reaction kinetics of the Nb2O5@NC composite. The obtained 600-Nb2O5@NC-2 anode exhibits superior rate capability and outstanding cycling stability, delivering a reversible capacity of 196 mA h g-1 at 1 A g-1 after 1000 cycles. Even at high current densities of 5 A g-1 and 10 A g-1, the long-life cycling tests show that the reversible capacities still remain at 128.4 mA h g-1 and 95.9 mA h g-1 after 3000 cycles, respectively, which is the best performance of Nb2O5-based anodes at high current densities so far. These results indicate that the feasible synthetic strategy of Nb2O5@NC is an effective approach to develop high-performance Nb2O5-based anodes for large-scale energy storage.

Superclear, Porous Cellulose Membranes with Chitosan-Coated Nanofibers for Visualized Cutaneous Wound Healing Dressing.

Easy and rapid continuous large-scale industrial production of transparent visualized cutaneous wound healing dressing from natural polymers is very worth studying in medical natural polymer materials and multifunction gauze dressing design fields. In this work, superclear, porous cellulose membranes (CMs) with chitosan-coated nanofibers were fabricated using a simple, one-step electrostatic spinning technology and evaluated as potential wound dressings. First, the pure CMs were dissolved by a simple physical method, and then, the membranes were regenerated in an acidic coagulation bath by the casting method. The chitosan solution was polarized into nanofibers and formed a continuous fiber mat on CMs because of the charge repulsion between molecules. The prepared chitosan-coated CMs (CM-CS) were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, tensile tests, and so forth. The results indicated that CM-CS showed high wettability, hydrophilicity, and gas permeability, in addition to excellent light transmittance and mechanical compliance. Cell cytotoxicity and morphology assay and antibacterial activity against Escherichia coli and Staphylococcus aureus were also studied. They exhibited good biocompatibility and antibacterial activity of CM-CS. Moreover, evaluation of an in vivo wound healing model in mice revealed that CM-CS had a good effect in promoting wound healing. This work provided an easy and rapid continuous large-scale industrial design strategy for natural bioresource-based wound dressing materials, which could act as potential wound dressings for clinical use.

AgO-decorated multi-dimensional chrysanthemum-like NiCo2O4 mounted on nickel foam as a highly efficient and stable electrocatalyst for the oxygen evolution reaction.

AgO nanoparticles were successfully integrated into NiCo2O4 nanosheets for enhanced electrochemical catalysis ability and stability in the oxygen evolution reaction (OER). The chrysanthemum-like NiCo2O4/AgO composites mounted on nickel foam (NF) were synthesized by a hydrothermal-calcination method. AgO upgraded the ratio of Co3+/Co2+ and thus regulated the intrinsic activity of the species. The highly hierarchical structure of NiCo2O4/AgO composed of 0D AgO nanoparticles, 1D NiCo2O4 needles, 2D NiCo2O4 nanosheets, and 3D chrysanthemum-like bundles grown on NF bestowed the high surface area and mesoporous structure for the easy evolution of O2. The Ni atoms in NiCo2O4 originating in situ from NF in the process of AgO formation produced an integrated electrode of the active component of NiCo2O4 bound on NF with a superb highway for charge transfer. AgO significantly tuned the structure and physicochemical properties of NiCo2O4. As a result, NiCo2O4/AgO/NF exhibited excellent OER performance with an overpotential of 232 mV to obtain a current density of 10 mAcm-2 in an alkaline electrolyte, and the catalyst showed a small loss of the initial catalyst activity for 50 h and over 5000 cycles. This study provides a pathway for developing high-performance OER electrocatalysts.

Multifunctional theranostic nanosystems enabling photothermal-chemo combination therapy of triple-stimuli-responsive drug release with magnetic resonance imaging.

Theranostic nanosystems are emerging as a promising approach for controlled drug delivery, diagnosis and multimodal therapeutics. Herein, a multifunctional theranostic nanoplatform is reported for photothermal-chemo combination therapy functioned with magnetic and thermal imaging. Hyaluronic acid (HA) coated Fe3O4@polydopamine nanoparticles equipped with redox-sensitive disulfide linkers have been subsequently deposited with an anticancer drug, doxorubicin (DOX) (termed as FPCH-DOX NPs). These nanocomposites possess an average diameter of 120 nm, a saturation magnetization of 28.5 emu g-1, DOX loading capacity of 7.13% and a transverse relaxation rate of 171.76 mM-1 s-1. The drug release could be triggered by pH, glutathione (GSH) concentration and light irradiation. Prussian blue staining and confocal microscopy demonstrate that these nanoplatforms have improved biocompatibility and cellular uptake in CD44-positive HeLa cell lines rather than in CD44-negative NIH 3T3 normal cell lines. In vitro evaluations demonstrate that the combination therapy of FPCH-DOX NPs lowers the cell viability to 16.2%, less than that of individual chemotherapy (55.3%) or PTT (52.1%). In vivo MRI indicates that the tumor accumulation of FPCH-DOX NPs provides enhanced MRI contrast, and in vivo thermal imaging verified their localized photothermal conversion effect in tumor tissues. Importantly, FPCH-DOX NPs present remarkable anti-tumor efficacy by photothermal-chemo combination therapy. H&E and Ki67 staining tests show obvious necrosis and weak cell proliferation at the region of the tumor. Thus, FPCH-DOX NPs are promising multifunctional nanoplatforms for highly effective cancer theranostics.

Correction: Solution growth and thermal treatment of crystals lead to two new forms of 2-((2,6-dimethylphenyl)amino)benzoic acid.

[This corrects the article DOI: 10.1039/C7RA13353G.].

Multifunctional theranostic agents based on prussian blue nanoparticles for tumor targeted and MRI-guided photodynamic/photothermal combined treatment.

The independence of photodynamic or photothermal modality create difficulties in the success of tumor therapy. In this current study, a multifunctional nanotheranostic agent of PDE-Ce6-HA was developed for tumor targeted and MRI-guided photodynamic/photothermal combined therapy (PDT/PTT). For this purpose, the near-infrared-absorbing nanoparticles of prussian blue were coated with polydopamine and successively conjugated with chlorin e6 (Ce6) for reactive oxygen species (ROS) generation. The resultant nanoparticles, denoted as PDE-Ce6, were then modified with hyaluronic acid (HA) through electrostatic interaction to yield the final therapeutic agent of PDE-Ce6-HA NPs. PDE-Ce6-HA NPs not only exhibited high colloid stability, good biocompatibility and suitable transverse relaxation rate (0.54 mM-1 s-1), but also high photothermal conversion efficiency (40.4%) and excellent ROS generation efficiency under NIR light irradiation. The confocal microscopy images demonstrated a selective uptake of PDE-Ce6-HA by CD44 overexpressed HeLa cells via HA-mediated endocytosis. Meanwhile, in vitro anti-cancer evaluation verified the significant photodynamic and photothermal combined effects of PDE-Ce6-HA on cancer cells. Moreover, PDE-Ce6-HA led to an increase of T1-MRI contrast in tumor site. Furthermore, in vivo anti-tumor evaluation proved that the PDE-Ce6-HA under both 808 and 670 nm laser showed significantly high tumor growth inhibition effects compared with individual PTT or PDT. Hence, PDE-Ce6-HA is applicable in tumor targeted and MRI-guided photodynamic/photothermal combined treatment.

A "Missile-Detonation" Strategy to Precisely Supply and Efficiently Amplify Cerenkov Radiation Energy for Cancer Theranostics.

Cerenkov radiation (CR) from radionuclides can act as a built-in light source for cancer theranostics, opening a new horizon in biomedical applications. However, considerably low tumor-targeting efficiency of existing radionuclides and radionuclide-based nanomedicines limits the efficacy of CR-induced theranostics (CRIT). It remains a challenge to precisely and efficiently supply CR energy to the tumor site. Here, a "missile-detonation" strategy is reported, in which a high dose of p-SCN-Bn-deferoxamine-porphyrin-PEG nanocomplex (Df-PPN) is first adminstered as a CR energy receiver/missile to passively target to tumor, and then a low dose of the 89 Zr-labeled Df-PPN is administrated as a CR energy donor/detonator, which can be visualized and quantified by Cerenkov energy transfer imaging, positron-emission tomography, and fluorescence imaging. Based on homologous properties, the colocalization of Df-PPN and 89 Zr-Df-PPN in the tumor site is maximized and efficient CR energy transfer is enabled, which maximizes the tumor-targeted CRIT efficacy in an optimal spatiotemporal setting while also reducing adverse off-target effects from CRIT. This precise and efficient CRIT strategy causes significant tumor vascular damage and inhibited tumor growth.

Fabrication of an N-doped mesoporous bio-carbon electrocatalyst efficient in Zn-air batteries by an in situ gas-foaming strategy.

A nitrogen doped bio-carbon catalyst with high specific surface area and a hierarchical interconnected porous structure was fabricated by an in situ gas-foaming strategy from sodium alginate and ammonium chloride. The optimized catalyst displays a fabulous ORR activity, providing a facile approach for the mass production of metal-free bio-carbon catalysts in fuel cells and metal-air batteries.

Development and Applications of MOFs Derivative One-Dimensional Nanofibers via Electrospinning: A Mini-Review.

Metal organic frameworks (MOFs) have been exploited for various applications in science and engineering due to the possibility of forming different mesoscopic frameworks and pore structures. To date, further development of MOFs for practical applications in areas such as energy storage and conversion have encountered tremendous challenge owing to the unitary porous structure (almost filled entirely with micropores) and conventional morphology (e.g., sphere, polyhedron, and rod shape). More recently, one-dimensional (1D) MOFs/nanofibers composites emerged as a new molecular system with highly engineered novel structures for tailored applications. In this mini-review, the recent progress in the development of MOFs-based 1D nanofibers via electrospinning will be elaborated. In particular, the promising applications and underlying molecular mechanism of electrospun MOF-derived carbon nanofibers are primarily focused and analyzed here. This review is instrumental in providing certain guiding principles for the preparation and structural analysis of MOFs/electrospun nanofibers (M-NFs) composites and electrospun MOF-derived nanomaterials.

Correction: Vehicle-saving theranostic probes based on hydrophobic iron oxide nanoclusters using doxorubicin as a phase transfer agent for MRI and chemotherapy.

Correction for 'Vehicle-saving theranostic probes based on hydrophobic iron oxide nanoclusters using doxorubicin as a phase transfer agent for MRI and chemotherapy' by Yanbing Cao et al., Chem. Commun., 2019, DOI: .

Vehicle-saving theranostic probes based on hydrophobic iron oxide nanoclusters using doxorubicin as a phase transfer agent for MRI and chemotherapy.

A simple approach for constructing theranostic nanobeads is developed by using doxorubicin as a phase transfer agent to solubilize small iron oxide nanoclusters. The nanobeads can be specifically internalized into cancer cells with the guidance of an external magnetic field, resulting in good MRI and chemotherapy.

Engineering Sustainable Antimicrobial Release in Silica-Cellulose Membrane with CaCO3-Aided Processing for Wound Dressing Application.

The sustained release of antimicrobial therapeutics for wound dressing has become an attractive design strategy for prolonging the timespan of wound dressings and for reducing the risk of chronic wound infection. Recently, cellulose-based membrane has become a preferred option of wound dressings for the treatment of burn wounds and skin ulcers. In this work, novel cellulose membrane incorporated with mesoporous silica particles (SBA-15) was developed as an antimicrobial wound dressing with desirable sustained release functionality for targeting persistent bacterial pathogens. Attributed to a coated layer of calcium carbonate (CaCO3), SBA-15 particles were free from corrosion in alkaline condition during the preparation of cellulose-based composite membranes. SEM, TEM and BET results showed that the morphology, specific surface area, pore size and pore volume of pristine SBA-15 were preserved after the incorporation of CaCO3-coated SBA-15 into the cellulose matrix, while the mesoporous structure of SBA-15 was significantly disrupted without the use of CaCO3 coating. The resultant composite membranes containing 30 wt% SBA-15 (denoted as CM-Ca2-SBA(30%)) achieved 3.6 wt% of antimicrobial drug loading. Interestingly, CM-Ca2-SBA(30%) demonstrated the sustained release property of chloramphenicol for 270 h, driven by a two-stage drug release processes of SBA-15/cellulose. The water vapor permeability (WVTR) and swelling properties of composite membranes were shown to have complied with the primary requirements of wound dressing. Antibacterial assays revealed that strong antibacterial activities (144 h) of the composite membranes against Staphylococcus aureus and Eschericia coli were achieved. All results displayed that the strategy of coating silica with CaCO3 helps to obtain cellulose-silica composite membranes with desirable sustained release profiles and strong antibacterial activities. The antibacterial SBA-15/cellulose composite membranes show potential for the application of wound dressing.