Synthesis of ß,ß-Dithioketones by Merging C-C and C-S Bond Cleavage in [1 + 1 + 1 + 1 + 1 + 1] Annulation.

An unconventional [1 + 1 + 1 + 1 + 1 + 1] annulation process was developed for the construction of ß,ß-dithioketones by merging C-C and C-S bond cleavage. In this reaction, rongalite concurrently served as triple C1 units, dual sulfur(II) synthons, and a reductant for the first time. Mechanism investigation indicated that the reaction involved the self-mediated valence state change of rongalite. By performing this step-economical method, the challenging construction of C5-substituted 1,3-dithiane can be achieved under mild and simple conditions.

Synthesis of polyoxometalate-pillared Zn-Cr layered double hydroxides for photocatalytic CO2 reduction and H2O oxidation.

Polyoxometalate (POM)-pillared Zn-Cr layered double hydroxides (LDHs) exhibited high photocatalytic activities in CO2 reduction and H2O oxidation reactions. For CO2 reduction in pure water, the CO production was 1.17 µmol g-1 after a 24 h reaction. For O2 evolution in NaIO3 solution, the O2 production reached 148.1 µmol g-1 after a 6 hour reaction. A mechanism study indicated that the electron transfer from Zn-Cr LDHs to POMs (SiW12O404-) promoted photocatalytic activities.

Scalable synthesis of BiVO4 thin films via anodic plating and thermal calcination.

Fabrication of high-quality semiconductor thin films has long been a subject of keen interest in the photocatalytic field. Here, we report a facile, solution-based anodic plating and calcination for large-scale synthesis of BiVO4 thin films on indium tin oxide coated glass for use as photoanodes in solar water splitting. Using Na2SO3 as a sacrificial reagent, continuous solar H2 production with 94% Faradaic efficiency was obtained over 6 h of photoelectrochemical water splitting.

Promoted Photothermal Catalytic CO Hydrogenation by Using TiC-Supported Co-Fe5 C2 Catalysts.

Photothermal catalytic CO hydrogenation offers the potential to synthesize light hydrocarbons by using solar energy. However, the selectivity and activity of the reaction are still far below those achieved in conventional thermal catalytic processes. Herein, we report that the Co-modified Fe5 C2 on TiC catalyst promotes photothermal catalytic CO hydrogenation with a 59 % C2+ selectivity in the produced hydrocarbons and a 30 % single-pass CO conversion at a high gas hourly space-time velocity of 12 000 mL g-1 h-1 . Using in-situ-irradiated XPS, we show that light-induced hot electron injection from TiC to Fe5 C2 modulates the chemical state of Fe, thereby increasing the CO-to-C2+ conversion. This work suggests that it is possible for plasmon-mediated surface chemistry to enhance the activity and selectivity of photothermal catalytic reactions.

[Application of hyaluronic acid microneedles in insulin intelligent delivery system for the treatment of diabetes].

In this study, insulin (insulin, INS)/Ca3PO4 complex and glucose oxidase (glucose oxidase, GOx)/Cu3(PO4)2 complex were prepared by coprecipitation method. The mineralized insulin (mineralized insulin, m-INS) showed irregular crystalline clusters, and the mineralized glucose oxidase (m-GOx) showed flower spherical morphology, with a diameter of about 1-2 µm. In vitro simulated release experiment showed that m-INS released INS as the pH value of the medium decreased. When the pH value was 4.5, the release amount reached 96.68%. The enzyme activity detection experiment showed that the enzyme activity stability of m-GOx was higher than that of free GOx. It still maintained high activity after 10 days at room temperature, while the activity of GOx was less than 60%. The glucose solution was prepared to simulate the state of normal blood glucose (5.6 mmol/L) and hyperglycemia (22.2 mmol/L). When m-INS and m-GOx were added to the glucose solution, the release amount of INS showed a significant glucose concentration dependence. The higher the glucose concentration, the greater the release amount and release rate of INS. Finally, m-INS, m-GOx and hyaluronic acid (HA) solution were mixed to prepare HA microneedle arrays loaded with m-INS and m-GOx. Type 1 diabetes mice were constructed to evaluate the effect of drug-loaded HA microarray on blood glucose control in diabetic rats. The results show that the HA microneedles loaded with m-INS/m-GOx could deliver drugs effectively. The average blood glucose concentration in diabetic rats dropped to about 7 mmol/L within 1 h, normal blood glucose concentration could be maintained for 10 h, and the overall blood glucose concentration was lower than the level before administration for 36 hours. Compared with HA microneedles loaded with INS only, m-ins microneedles showed better glucose tolerance, longer-lasting glucose control effect and less risk of hypoglycemia. Compared with other sustained-release systems, the preparation process of the core components in this study is simple, efficient, safe and effective, and has great commercial potential.

Facile Synthesis of Graphene with Fast Ion/Electron Channels for High-Performance Symmetric Lithium-Ion Capacitors.

With the battery-type anode and capacitor-type cathode, lithium-ion capacitors (LICs) are expected to exhibit both high energy and high power density but suffer from the mismatch of the electrode reaction kinetics and capacity. Herein, to alleviate the mismatch between the two electrodes and synergistically enhance the energy/power density, we design a method of microwave irradiation reduction to prepare graphene-based electrode material (MRPG/CNT) with fast ion/electron pathway. The three-dimensional structure of CNT intercalation to graphene inhibits the restacking of graphene sheets and improves the conductivity of the electrode material, resulting a rapid ion and electron diffusion channel. Due to its specific properties, MRPG/CNT materials can be used as both anode and cathode electrodes of LICs at the same time. As anode, MRPG/CNT shows a high capacity of 1200 mAh g-1 as well as high rate performance. As cathode, MRPG/CNT displays a high capacity of 108 mAh g-1 and the capacity retention of 100% after 8000 cycles. Coupling the prelithiated MRPG/CNT anode with MRPG/CNT cathode gives a full-graphene-based symmetric LIC, which achieves a high energy density of 232.6 Wh kg-1 at 226.0 W kg-1, 111.2 Wh kg-1 at the ultrahigh power density of 45.2 kW kg-1, and superior capacity retention of 86% after 5000 cycles. The structure design of this electrode provides a new strategy for alleviating the mismatch of LIC electrodes and constructing high-performance symmetrical LICs.

Oxidized-Polydopamine-Coated Graphene Anodes and N,P Codoped Porous Foam Structure Activated Carbon Cathodes for High-Energy-Density Lithium-Ion Capacitors.

As a tradeoff between supercapacitors and batteries, lithium-ion capacitors (LICs) are designed to deliver high energy density, high power density, and long cycling stability. Owing to the different energy storage mechanisms of capacitor-type cathodes and battery-type anodes, engineering and fabricating LICs with excellent energy density and power density remains a challenge. Herein, to alleviate the mismatch between the anode and cathode, we ingeniously designed a graphene with oxidized-polydopamine coating (LG@DA1) and N,P codoped porous foam structure activated carbon (CPC750) as the battery-type anode and capacitor-type cathode, respectively. Using oxidized-polydopamine to stabilize the structure of graphene, increase layer spacing, and modify the surface chemical property, the LG@DA1 anode delivers a maximum capacity of 1100 mAh g-1 as well as good cycling stability. With N,P codoping and a porous foam structure, the CPC750 cathode exhibits a large effective specific surface area and a high specific capacity of 87.5 mAh g-1. In specific, the present LG@DA1//CPC750 LIC showcases a high energy density of 170.6 Wh kg-1 and superior capacity retention of 93.5% after 2000 cycles. The success of the present LIC can be attributed to the structural stability design, surface chemistry regulation, and enhanced utilization of effective active sites of the anode and cathode; thus, this strategy can be applied to improve the performance of LICs.

Monolayer Amorphous Carbon-Bridged Nanosheet Mesocrystal: Facile Preparation, Morphosynthetic Transformation, and Energy Storage Applications.

Self-assembly of nanoscale building units into mesoscopically ordered superstructures opens the possibility for tailored applications. Nonetheless, the realization of precise controllability related specifically to the atomic scale has been challenging. Here, first, we explore the key role of a molecular surfactant in adjusting the growth kinetics of two-dimensional (2D) layered SnS2. Experimentally, we show that high pressure both enhances the adsorption energy of the surfactant sodium dodecylbenzene sulfonate (SDBS) on the SnS2(001) surface at the initial nucleation stage and induces the subsequent oriented attachment (OA) growth of 2D crystallites with monolayer thickness, leading to the formation of a monolayer amorphous carbon-bridged nanosheet mesocrystal. It is notable that such a nanosheet-coalesced mesocrystal is metastable with a flowerlike morphology and can be turned into a single crystal via crystallographic fusion. Subsequently, direct encapsulation of the mesocrystal via FeCl3-induced pyrrole monomer self-polymerization generates conformal polypyrrole (PPy) coating, and carbonization of the resulting nanocomposites generates Fe-N-S-co-doped carbons that are embedded with well-dispersed SnS/FeCl3 quantum sheets; this process skillfully integrated structural phase transformation, pyrolysis graphitization, and self-doping. Interestingly, such an integrated design not only guarantees the flowerlike morphology of the final nanohybrids but also, more importantly, allows the thickness of petalous carbon and the size of the nanoconfined particles to be controlled. Benefiting from the unique structural features, the resultant nanohybrids exhibited the brilliant electrochemical performance while simultaneously acting as a reliable platform for exploring the structure-performance correlation of a Li-ion battery (LIB).

Arginine-glycine-aspartate (RGD)-targeted positron-labeled dendritic polylysine nanoprobe for tumor PET imaging.

This work investigated the optimization of the 68Ga radiolabeling of the dendritic polylysine-1,4,7-triazacyclononane-1,4,7-triacetic acid conjugate (DGL-NOTA). Under pH = 4.0, reaction temperature of 70 °C, and incubation time of 10.0 min, the conjugate (DGL-NOTA) radiochemical yield was between 50% and 70%. After separation and purification, the radiochemical purity was greater than 98%. The radiolabeled formulation (68Ga-NOTA-DGL-PEG-RGDyC) remained stable in both phosphate buffer and serum (all radiochemically greater than 95%) for up to 2 hours with a specific activity of 30 GBq/µmol. Cellular experimental studies have shown that radiolabeled preparations can rapidly enter U87MG cells, and after 2 hours, there was still retention of imaging agents in the cells. In vivo distribution studies had shown that the tracer is excreted by the kidneys. Two hours after injecting the imaging agent, the U87MG tumor tissue uptake value was (4.67 ± 0.09)% ID/g. Positron emission tomography (PET) imaging in animals showed that 68Ga-NOTA-DGL-PEG-RGDyC had good targeting and can be enriched in tumor sites. Through hemolysis testing and morphological changes of red blood cells, it was proved that NOTA-DGL-PEG-RGDyC has good blood compatibility.