Efficient electrocatalytic CO2 reduction to ethanol through the proton coupled electron transfer process of PVnMo(12-n) (n = 1, 2, 3) over indium electrode.

The multistep proton-coupled electron transfer (PCET) processes are beneficial for products distribution and selectivity of the electrocatalytic CO2 reduction reaction (CO2RR), which are affected by the nature of the catalyst and electrolyte at electrode-electrolyte interface. Polyoxometalates (POMs) are electron regulators of PCET processes, which can catalyze CO2RR effectively. Accordingly, the commercial indium electrodes are combined in this work with a series of Keggin-type POMs (PVnMo(12-n)O40)(n+3)-, n = 1, 2, 3) to process CO2RR with Faradaic efficiency toward ethanol reaching 93.4% at -0.3 V (vs. RHE). The cyclic voltammetry and X-ray photoelectron spectroscopy results reveal the activation of CO2 molecules by the first PCET process of the VⅤ/Ⅳ in POM. Subsequently, the PCET process of MoⅥ/Ⅴ results the oxidation of the electrode, causing the loss of In0 active sites. Electrochemical in-situ infrared spectroscopy confirms the weak adsorption of *CO at the later stage of electrolysis due to the oxidation of the In0 active sites. The indium electrode in PV3Mo9 system retains more In0 active sites owing to the highest V-substitution ratio, thereby ensuring a high adsorption ratio of *CO and CC coupling. In sum, the regulation of the interface microenvironment by POM electrolyte additives can be used to boost the performance of CO2RR.

Fabrication of Hydroxy-Terminated Polybutadiene with Piezoelectric Property by Functionalized Branch Chain Modification.

Hydroxyl-terminated polybutadiene (HTPB)-based piezoelectric polymer (m-HTPB) is prepared for the first time by functionalized branch chain modification strategy. In the presence of HTPB with >98.8% cis-1,4 content, the C=C bond partly breaks down, and functionalized acetylferrocene groups are introduced to the cis-1,4 polybutadiene branch chain, retaining the high cis-1,4 content of HTPB. The whole process is conducted under mild conditions, without complicated manipulations. The microstructure and molecular weight of m-HTPB are characterized by Fourier-transform infrared (FTIR) spectra, 1H or 13C nuclear magnetic resonance spectrum (NMR), and gel permeation chromatography (GPC). The thermal properties of HTPB and m-HTPB are determined by differential scanning calorimetry (DSC). Electrochemical investigations reveal that m-HTPB exhibits higher conductance compared with HTPB. The m-HTPB flexible piezoelectric polymer is further used for in situ and real-time pressure monitoring. This simple and effective strategy provides a promising polymeric material for flexible piezoelectric sensors.

LDH hybrid thermosensitive hydrogel for intravaginal delivery of anti-HIV drugs.

Microbicides based on hydrogel have become an effective way to prevent the HIV replication and transmission because of their convenience and prolonging drug release. In this study, a hybrid thermo-sensitive hydrogel constituted by nanosized layered double hydroxides and poloxamer 407 (P407) was constructed and co-loaded with both hydrophobic and hydrophilic drug. The LDH-P407 hydrogel could achieve sol-gel transition at body temperature. The in vivo experiment showed that LDH-P407 hydrogel can achieve controlled release of theaflavin and Nile red (hydrophobic drug model) into blood by vaginal drug delivery, meanwhile the hydrogel showed barely mucosal irritation. In addition, ex vivo experiment showed that the nifeviroc-loaded LDH-P407 hydrogel was able to specifically bind co-receptor CCR5 of DCs cells. Therefore, the LDH-P407 hydrogel would be a promising carrier for intravaginal delivery of anti-HIV drugs.

A Target-Directed Chemo-Photothermal System Based on Transferrin and Copolymer-Modified MoS2 Nanoplates with pH-Activated Drug Release.

Molybdenum disulfide (MoS2 ) nanosheets have attracted significant attention due to their photothermal properties, but the poor solubility and colloidal stability limited their further application in biomedical field. Here, we report a targeted photothermal controllable nanocarrier consisting of MoS2 nanosheets modified with block copolymer P(OEG-A)-b-P(VBA-co-KH570) and targeting ligand transferrin. P(OEG-A)-b-P(VBA-co-KH570) is synthesized by RAFT polymerization and utilized not only to improve the solubility of MoS2 nanosheets but also efficiently load the anti-cancer drug doxorubicin (DOX) through an acid-cleavable Schiff base linker. Thiol-functionalized transferrin (Tf-SH) is anchored onto the surface of MoS2 nanosheets by the formation of disulfide bonds, which could further enhance the cellular uptake of DOX and MoS2 to HepG2 cells for high-efficiency synergetic therapy. The drug release experiments exhibited the minimal release of DOX at room temperature and neutral pH, and the maximal drug release of 53 % at acidic tumor pH and hyperthermia condition after 48 h. In addition, the DOX-loaded, Tf-SH and P(OEG-A)-b-P(VBA-co-KH570) modified MoS2 (DOX-POVK-MoS2 -Tf) showed better a therapeutic effect than DOX-POVK-MoS2 and POVK-MoS2 , probably owing to the combined effects of target-directed uptake, acid-triggered drug release, and NIR induced localized heating, which suggest the designed MoS2 nanocarriers are promising for applications in multi-modal cancer therapy.