Latest ArticlesHalide electrolytes in solid-state batteries with excellent oxidative stability and high ionic conductivity have been well reported recently. However, the high-cost rare-earth elements and long duration of high-rotation milling procure are the major obstacles. Herein, we have successfully synthesized the low cost Li2.25Zr0.75Fe0.25Cl6 electrolyte consisting of abundant elements with comparable Li-ion conductivity in a short milling duration of 4 h. Phase transition of the annealed sample was also carefully investigated. LiNi0.6Co0.2Mn0.2O2/Li2.25Zr0.75Fe0.25Cl6/Li5.5PS4.5Cl1.5/In-Li batteries using different halide electrolytes were constructed and cycled at different voltage windows. Solid-state battery using Li2.25Zr0.75Fe0.25Cl6 electrolyte obtained from long milling duration delivers higher discharge capacities and superior capacity retention than shorter milling time between 3.0 and 4.3 V. It delivers much higher discharge capacity when cycled at elevated temperature (60 ℃) and suffers fast capacity degradation when the upper cut-off voltage increases to 4.5 V at the same current density. This work provides an efficiency synthesis strategy for halide solid electrolyte and studies its applications in all-solid-state batteries in a wide temperature range.
Molybdenum disulfide (MoS2) has attracted great attention in hydrogen peroxide (H2O2) activation as a Fenton-like catalyst and cocatalyst, but the distinct mechanism of generating •OH remains unclear. In this paper, the metallic 1T phase and semiconducting 2H phase of MoS2 nanosheets were prepared and applied in MoS2/H2O2 and MoS2/Fe2+/H2O2 systems with and without light irradiation. Compared with 2H-MoS2, 1T-MoS2 exhibited superior removal rates in degrading organic pollutants in the two systems under light irradiation. However, the phase had little effect on activating H2O2 in the MoS2/H2O2 system under dark conditions. This is because it was difficult for the surface •OHads generated in the MoS2/H2O2 system to diffuse into solution, while the •OHfree radicals were mainly responsible for degrading organic pollutants. When introducing light irradiation, external energy may accelerate the desorption of •OHads into •OHfree. Interestingly, the conversion between Mo4+ and Mo5+ triggered the decomposition of H2O2 in the Fenton-like reaction, while the cycle of Mo4+/Mo6+ promoted the regeneration of Fe3+ when employing 1T-MoS2 as a cocatalyst. Meanwhile, the 1T-MoS2 catalysts exhibited excellent stability and ability to degrade various organics in the two systems. This work offers deeper insight into the MoS2-based Fenton-like and cocatalytic mechanisms.
Two-photon imaging has attracted increasing attention owing to its deep tissue imaging capabilities. Therefore, many fluorophores have been developed to satisfy its requirements. However, long-wavelength emission fluorophores with an optically tunable group are rarely developed. In this study, two long-wavelength emission fluorophores with an optically tunable amino group were successfully developed by introducing strong electron acceptor and large conjugated group to the TPQL dye. TPCO2 displayed a bright red emission (λem = 638 nm, Φ = 0.15) together with high two-photon action cross section and good water solubility, which enabled higher signal-to-background ratios and deep tissue imaging. The proof-of-concept probe (TPCONO2) was successfully applied to the high signal-to-background ratio imaging of nitroreductase in liver fibrosis, further realizing diagnosis of the degree of hypoxia during liver fibrosis.
The origin of regioselectivity in meta-selective C-H borylation of benzamides directed by hydrogen bond interaction between ligand and substrate is elucidated through combined computational and experimental studies. We discover that a non-directed pathway, in which the urea moiety in ligand recognizes the O atom in Bpin instead of substrate, competes with the directed pathway and erodes the meta-selectivity. The non-directed pathway is sensitive to steric repulsion between Bpin and urea, and thus can be impeded by introducing a bulky substituent into the urea moiety. Accordingly, we optimize the ligand and improve the meta-selectivity in the Ir-catalyzed C-H borylation of some previously reported unsuccessful arenes.
Information-carrying capacity has become an important factor in the development of encryption and anti-counterfeiting. Herein, a hydrogen-bonded organic framework (HOF-PyTTA) was developed as novel anti-counterfeiting ink without rare metals and a smartphone-based APP was written for encryption and anti-counterfeiting. We found that the fluorescence of HOF-PyTTA can be quenched by Fe3+ ions and recovered by the addition of ascorbic acid. And the fluorescence of HOF-PyTTA can be enhanced by the increasing concentrations of ethanol. Based on these stimulus-response properties, four anti-counterfeiting models with gradually increased security were studied. Mode one was printed by HOFs ink and decrypted by UV light. Mode two was based on HOF-PyTTA and CsPbBr3 inks (or HOF-PyTTA-Fe3+) which are used to separately print the genuine and pirated information. A decryption reagent was applied to get the genuine information. Furthermore, we successfully construct a dynamic information encryption anti-counterfeiting model using a fluorescence array in combination with an information encryption anti-counterfeiting APP. The circular array is printed by several concentrations of HOF-PyTTA ink and different RGB thresholds are set with the help of the information encryption anti-counterfeiting APP, to obtain distinct encrypted anti-counterfeiting information, thus accomplishing a high information-carrying capacity.
Protein self-labeling tags achieve selective fusion and labeling of target proteins through genetic coding technology, but require exogenous fluorescent probes with fluorogenicity for protein tag binding to have the performance of wash-free fluorescence imaging in live cells. In this paper, we reported a fluorogenic probe 1 capable of ratiometric fluorescence recognition of SNAP-tag proteins. In this probe, the O6-benzylguanine derivative of 3–hydroxy-1,8-naphthalimide underwent a selective covalent linkage reaction with SNAP-tag protein. The hydroxyl group on the naphthalimide fluorophore formed a hydrogen bond with the functional group near the protein cavity. The excited state proton transfer occurred after illumination, to obtain the ratio fluorescence signal from blue emission to red emission, realizing the wash-free fluorescence imaging of the target proteins.
Polyoxometalates (POMs) have conducive properties such as controlled Brønsted and Lewis acidity, high thermal stability, nontoxic nature, tunable solubility, and less corrosiveness. POMs have been extensively applied in catalytic organic reactions and have an exciting prospect for industrial applications. This review summarized recent progress in the application of POMs as acid catalysts for various organic reactions including CC bond formation, CN bond formation, CO bond formation, heterocyclic synthesis reactions, cyanosilylation and hydrolysis reactions. Various POMs catalysts including heteropoly acids (HPAs) and cationic functionalized HPAs with Brønsted acidity, HPAs supported on non-precious metal support with Brønsted acidity (or both Brønsted and Lewis acidity), transition metal substituted POMs with Lewis acidity were applied in above reactions. This review attempts to provide up-to-date information about POMs acid-catalyzed organic reactions and propose future prospects.
A novel palladium-catalyzed carbonylative cyclization of alkene-tethered indoles with phenols or arylboronic acids is described, which provides a facile approach to access indolo[2,1-a]isoquinoline scaffolds. This method employs benzene-1,3,5-triyl triformate (TFBen) as the CO surrogate for the incorporation of a carbonyl group into indolo[2,1-a]isoquinoline scaffolds, and a variety of carbonyl-containing indolo[2,1-a]isoquinoline derivatives are prepared in good yields.
Electrocatalytic nitrate reduction to ammonia (NRA) under ambient conditions is significant for carbon-neutral synthetic fuels. Nevertheless, the lack of efficient electrocatalysts with tunable nanostructure for NRA remains a grand challenge. Herein, NbWO6 nanosheets with oxygen vacancy (NbWO6-x) was demonstrated via thermal treatment and exfoliation with NH3 selectivity of 86.8% and Faradaic efficiency of 85.7% toward NRA. 1H nuclear magnetic resonance spectra coupled with 15N isotope labeling experiments proved that NH3 originated from NO3−. The function of oxygen vacancy was revealed by computational studies in NRA. Moreover, the reaction mechanism and pathway of NRA could be deduced based on the results of online differential electrochemical mass spectrometry (DEMS). This work provides a selective NH3 generation strategy to decarbonize the energy-chemical sector, bridging the gap between batteries and biofuels.
More and more antibiotics that are difficult to biodegrade have been detected in water environments threatening ecosystems and human health. Therefore, it is urgent to develop efficient water treatment methods to degrade antibiotics. In this work, Co-Fe Prussian blue analogues (PBAs) with different molar ratios were synthesized for peroxymonosulfate (PMS) activation to degrade sulfacetamide (SAM, 10 mg/L). By increasing Co molar ratio, the PMS activation capability and electrochemical properties of PBAs were enhanced. Due to its excellent reactivity (degradation efficiency of 84.2% and mineralization efficiency of 52.79%), cost benefit (electrical energy per order, 0.01019 kWh/L) and lower metal leaching ([Co] = 0.259 mg/L, [Fe] = 0.128 mg/L), PBA-1, the as-prepared catalyst with a molar ratio of cobalt to iron of 1:1, was selected for further study. The radical scavenging experiments and an electron paramagnetic resonance (EPR) trapping experiments were performed and revealed that PBA-1 addition was required to produced •OH and SO4•− from PMS activation. Accordingly, we proposed a PMS activation mechanism and SAM decomposition pathways for PBA-1/PMS reaction system. Besides, a PBA-1@polyvinylidene fluoride (PVDF) catalytic membrane was further prepared to expand the application potential of PBA nanoparticles. The PBA-1@PVDF catalytic membrane was highly effective and exhibited a great reusability; thus, it could be considered for applications in actual water treatment processes.