Latest ArticlesDynamic assembly on time scale is common in biological systems but rare for artificial materials, especially for smart luminescent materials. Programming molecular assembly in a spatio-temporal manner and resulting in white-light-including multicolor fluorescence with time-dynamic features remains challenging. Herein, controlling molecular assembly on time scale is achieved by integrating a pH-responsive motif to a transient alkaline solution which is fabricated by activators (NaOH) and deactivators (esters), leading to automatic assembly on time scale and time-dependent multicolor fluorescence changing from blue to white and yellow. The kinetics of the assembly process is dependent on the ester hydrolysis process, which can be controlled by varying ester concentrations, temperature, initial pH, stirring rate and ester structures. This dynamic fluorescent system can be further developed for intelligent fluorescent materials such as fluorescent ink, three-dimension (3D) codes and even four-dimension (4D) codes, exhibiting a promising potential for information encryption.
To surmount the obstacles of traditional Fenton method and synchronously utilize Cu2+ and polyphenol in water, an improved Fenton-like reaction applying calcium peroxide (CaO2) as H2O2 source and regulating by the complex of Cu2+-tartaric acid (TA, a representative of polyphenol) was constructed. A typical antibiotic, metronidazole (MTZ) could be effectively eliminated by the Cu2+/TA/CaO2 system, and the optimized parameters were as follows: 0.1 mmol/L Cu2+, 2 mmol/L TA, 2 mmol/L CaO2, and initial pH 5. UV spectrum confirmed the formation of Cu2+-TA complex, which promoted the Cu2+/Cu+ circulation through decreasing the Cu2+/Cu+ couple redox potential, which further enhanced the H2O2 decomposition and the formation of reactive species. Hydroxyl radical was dominant for MTZ degradation, followed by oxygen and superoxide radical. The degradation intermediates of MTZ were detected and their evolution way was speculated. Furthermore, the ternary process showed a wide pH tolerance (3–8) for removing MTZ and broad applicability for eliminating other dyes and antibiotics. This work provided a reference for Cu-based Fenton-like strategy for organic wastewater settlement.
Electrochemical CO reduction (ECOR) as a potential strategy for producing valuable chemicals and fuels has captured substantial attention. However, the currently available electrocatalysts suffer from poor selectivity and low Faradaic efficiency, limiting their industrial application. Herein, we systematically investigate the potential of homonuclear bimetallic electrocatalysts, TM2@C9N4 (TM = Fe, Co, Ni, and Cu), for the ECOR through extensive density functional theory calculations. Our findings suggest that all four proposed monolayers exhibit exceptional stability, making them highly suitable for experimental synthesis and practical applications. Interestingly, these transition-metal dual atoms anchored on C9N4 monolayers show great potential in facilitating the production of high-value C2 products, such as C2H5OH and C2H4, due to the significantly low limiting potentials (-0.06~-0.46 V) and small kinetic energy barriers (0.54–1.08 eV) for the CO coupling process. Moreover, with the exception of Ni2@C9N4, these bimetallic catalysts demonstrate the impressive suppression of the competitive hydrogen evolution reaction (HER), leading to a high selectivity for C2 products in ECOR. Our predictions would accelerate the development of high-performance C9N4-based dual-atom catalysts for the ECOR.
Oral administration is the most acceptable route of drug delivery at this stage due to its convenience, safety, and non-invasiveness. However, drugs given orally are exposed to a complex gastrointestinal environment, causing a tremendous challenge for their successful absorption into the circulation. Over the past decades, researchers have developed various novel pharmaceutical technologies to improve oral absorption, among which the vesicular drug delivery system (like liposomes, niosomes and transfersomes) has received extensive attention. Encouragingly, there have been several investigations confirming the improved effect of vesicular drug delivery systems on oral drug absorption. Nevertheless, the clinical translation of oral vesicular drug delivery systems has been less impressive than implied by the positive results, and few vesicular formulations for oral use have been marketed yet. Against this background, this article provides an overview of the current applications and challenges associated with the vesicular delivery systems available for oral drug delivery, specifically liposomes, niosomes, transfersomes, chitosomes and bilosomes. The composition, formation mechanism, drug delivery advantages and application cases of these carriers in oral drug delivery are summarized. The possible mechanisms by which vesicular carriers enhance oral drug absorption are analyzed in terms of the in vivo process of oral drugs. Further, the challenges that oral vesicular carriers now face, such as safety, undefined in vivo fate, and scale-up production, are summarized, while possible strategies to deal with them are indicated. By reviewing the aforementioned, it can facilitate a more comprehensive knowledge of vesicular systems that can be used for oral drug delivery, providing a theoretical basis and reference for the design of oral formulations.
The steep reduction in costs and systematic optimization of renewable electricity has ignited an intensifying interest in harnessing electroreduction of carbon dioxide (CO2RR) for the generation of chemicals and fuels. The focus of research over the past few decades has been on the optimization of the electrode and the electrolyte environment. Notably, cation species in the latter have recently been found to dramatically alter the selectivity of CO2RR and even their catalytic activity by multiple orders of magnitude. As a result, the selection of cations is a critical factor in designing catalytic interfaces with high selectivity and efficiency for targeted products. Informed decision-making regarding cation selection relies on a comprehensive understanding of prevailing electrolyte effect models that have been used to elucidate observed experimental trends. In this perspective, we review the hypotheses that explain how electrolyte cations influence CO2RR by mechanisms such as through tuning of the interfacial electric field, buffering of the local pH, stabilization of the key intermediates and regulation of the interfacial water. Our endeavor is to elucidate the molecular mechanisms underpinning cation effects, thus fostering the evolution of more holistic and universally applicable predictive models. In this regard, we highlight the current challenges in this area of research, while also identifying potential avenues for future investigations.
All solid-state lithium metal batteries (ASSLMBs) based on polymer solid electrolyte and lithium metal anode have attracted much attention due to their high energy density and intrinsic safety. However, the low ionic conductivity at room temperature and poor mechanical properties of the solid polymer electrolyte result in increased polarization and poor cycling stability of the Li metal batteries. In order to improve the ionic conductivity at room temperature while maintaining mechanical strength, we combine the conductivity of short chain polyethylene oxide (PEO) and strength of styrene-maleic anhydride copolymer (SMA) to obtain a grafted block copolymer with nanophase separation structure, which has room temperature ionic conductivity up to 1.14 × 10−4 S/cm and tensile strength up to 1.4 MPa. Li||Li symmetric cell can work stably for more than 1500 h under the condition of 0.1 mA/cm2. Li||LiFePO4 full cells can deliver a high capacity of 151.4 mAh/g at 25 ℃ and 0.2 C/0.2 C charge/discharge conditions, showing 85.6% capacity retention after 400 cycles. Importantly, the all solid state Li||LiFePO4 pouch cell shows excellent safety performance under different abuse conditions. These results demonstrate that the nanophase separated, grafted alternate copolymer electrolyte has huge potential for application in Li metal batteries.
The efficient and environmentally friendly recycling technology of waste residue that including abundant heavy metal produced during the recovery of lithium batteries has become a research hotspot. Herein, a novelty process of acid leaching-selective electrodeposition-deep impurity removal-regeneration was proposed to recovery of the CuS slag, which has been efficient transferred to high purity cathode copper and commercially available ternary precursors. Copper cathode with a purity of 99.67% was prepared under electrochemical reaction conditions at −0.55 V for 2 h. A novel impurity remover-Mn powder, which was used to remove the residual impurities and as a feedstock for the ternary precursor. Finally, NCM523 was regenerated by co-precipitation. The process is superior to the traditional process in economy, energy consumption, CO2 emissions, product purity and process duration. This study provides a new approach for solid waste recovery and precious metal enrichment.
Four new cyclohexapeptides, pyridapeptides F–I (1–4), were isolated from the fermentation broth of marine sponge-derived Streptomyces sp. OUCMDZ-4539. The pyridapeptides F–H (1–3) are composed of β-hydroxyleucine, alanine, O-methylthreonine, hexahydropyridazine-3-carboxylic acid, 5-hydroxytetrahydropyridazine-3-carboxylic acid, and (2S,3R,4E,6E)-2-amino-3–hydroxy-4,6-dienoic acid residues. Pyridapeptide Ⅰ (4) contains (2S,3R,4E,6E)-2-amino-3–hydroxy-8-methylnona-4,6-dienoic acid residue and a very rare glycose residue, aculose. Their structures were determined based on spectroscopic analysis and chemical methods. Pyridapeptides G–I (2–4) have the 2,3,6-trideoxyhexose units glycosylated at the γ-OH-TPDA residue, displayed significant antiproliferative activity against four (PC9, MKN45, HepG2, K562) or two (PC9, MKN45) human cancer cell lines.
Chemical sensor arrays can obtain more comprehensive analyte information through high-dimensional data. It is of great significance in the analysis of multi-component complex samples. This review summarizes the development and status of chemical sensor arrays. We focused on the design of chemical sensor arrays based on various sensing materials. In addition, several pattern recognition methods in chemometrics are introduced. And applications of chemical sensor arrays in food monitoring, medical diagnosis, and environmental monitoring are illustrated. Based on the analysis of the limitations of current sensor array technology, the direction of the array is also predicted. This review aims to help the broad readership understand the research state of chemical sensor arrays and their development prospects.
A solid electrolyte interphase (SEI) with a robust mechanical property and a high ionic conductivity is imperative for high-performance zinc metal batteries. However, it is difficult to form such a SEI directly from an electrolyte. In this work, a molecular crowding effect is based on the introduction of Zn(OTF)2 and Zn(ClO4)2 to 2 mol/L ZnSO4 electrolytes. Simulations and experiments indicate that the Zn(OTF)2 and Zn(ClO4)2 not only create a molecularly crowded electrolyte environment to promote the interaction of Zn2+and OTF−, but also participate in the reduction to construct a robust and high ionic-conductive SEI, thus promoting metal zinc deposition to the (002) crystal surface. With this molecular crowding electrolyte, a high current density of 1 mA/cm2 can be obtained by assembling symmetric batteries with Zn as the anode for over 1000 h. And in a temperature environment of −10 ℃, a current density of 1 mA/cm2 can be obtained by assembling symmetric batteries with Zn for over 200 h. Zn//Bi2S3/VS4@C cells achieve a CE rate of up to 99.81% over 1000 cycles. Hence, the utilization of a molecular crowding electrolyte is deemed a highly effective approach to fabricating a sophisticated SEI for a zinc anode.