In Situ Conversion of Cu3P Nanowires to Mixed Ion/Electron‐Conducting Skeleton for Homogeneous Lithium Deposition

The introduction of 3D wettable current collectors is one of the practical strategies toward realizing high reversibility of lithium (Li) metal anodes, yet its effect is usually insufficient owing to single electron‐conductive skeleton. Here, homogeneous Li deposition behavior and enhanced Coulombic efficiency is reported for electrochemically lithiated Cu₃P nanowires, owing to the formation of a mixed ion/electron‐conducting skeleton (MIECS). In particular, by evaluating the Gibbs free energy change, the possible chemical reaction between Cu₃P and molten Li is used to construct a MIECS containing Li₃P and Cu–Li alloy phase. The successful conversion of Cu₃P nanowires to Li₃P and Cu–Li alloy nanocomposite not only greatly reduces the surface energy between molten Li and Cu₃P, but also induces uniform Li stripping/plating behavior via balanced ion/electron transport. Thus, the as‐obtained Li@MIECS composite anode displays superior cycling stability in both symmetric cells and full cells. This work provides a promising option for the preparation of high‐performance composite Li anodes containing MIECS by thermally pre‐storing Li.     

Ultraviolet Photoemission Spectroscopy and Kelvin Probe Measurements on Metal Halide Perovskites: Advantages and Pitfalls

In this essay, a case study is presented on the electronic structure of several metal halide perovskites (MHP) using Kelvin probe (KP)‐based surface photovoltage (SPV) measurements and ultraviolet photoemission spectroscopy (UPS) to demonstrate the advantages, but also the pitfalls, of using these techniques to characterize the surfaces of these materials. The first part addresses the loss of halide species from perovskite surfaces upon supragap illumination in vacuum. This has the potential to cause both a long‐term alteration of the sample work function and a modification of the KP tip during SPV measurements. If undetected, this leads to a misinterpretation of the MHP surface potential. The second part illustrates the difficulties in determining the valence band maximum (VBM) of MHP surfaces with UPS and stresses the importance of taking into account the low density of states at the VBM edge. Given this circumstance, specific care must be taken to eliminate measurement artifacts in order to ascertain the presence or absence of low densities of electronic gap states above the VBM. This essay also highlights issues such as film degradation, nonequilibrium situations (e.g., SPV), and satellite emissions, which occur during photoemission spectroscopy.     

Nonwoven rGO Fiber‐Aramid Separator for High‐Speed Charging and Discharging of Li Metal Anode

Li metal, which has a high theoretical specific capacity and low redox potential, is considered to the most promising anode material for next‐generation Li ion‐based batteries. However, it also exhibits a disadvantageous solid electrolyte interphase (SEI) layer problem that needs to be resolved. Herein, an advanced separator composed of reduced graphene oxide fiber attached to aramid paper (rGOF‐A) is introduced. When rGOF‐A is applied, F^? anions, generated from the decomposition of the LiPF₆ electrolyte during the SEI layer formation process form semi‐ionic C? F bonds along the surface of rGOF. As Li⁺ ions are plated, the “F‐doped” rGO surface induces the formation of LiF, which is known as a component of a chemically stable SEI, therefore it helps the Li metal anode to operate stably at a high current of 20 mA cm^?2 with a high capacity of 20 mAh cm^?2. The proposed rGOF‐A separator successfully achieves a stable SEI layer that could resolve the interfacial issues of the Li metal anode.     

Enhanced Rate Capability of Ion‐Accessible Ti3C2Tx‐NbN Hybrid Electrodes

Although 2D Ti₃C₂T_x is a good candidate for supercapacitors, the restacking of nanosheets hinders the ion transport significantly at high scan rates, especially under practical mass loading (>10 mg cm^?2) and thickness (tens of microns). Here, Ti₃C₂T_x‐NbN hybrid film is designed by self‐assembling Ti₃C₂T_x with 2D arrays of NbN nanocrystals. Working as an interlayer spacer of Ti₃C₂T_x, NbN facilitates the ion penetration through its 2D porous structure; even at extremely high scan rates. The hybrid film shows a thickness‐independent rate performance (almost the same rate capabilities from 2 to 20 000 mV s^?1) for 3 and 50 µm thick electrodes. Even a 109 µm thick Ti₃C₂T_x‐NbN electrode shows a better rate performance than 25 µm thick pure Ti₃C₂T_x electrodes. This method may pave a way to controlling ion transport in electrodes composed of 2D conductive materials, which have potential applications in high‐rate energy storage and beyond.     

Recent chemo‐/biosensor and bioimaging studies based on indole‐decorated BODIPYs

BODIPY is an important fluorophores due to its enhanced photophysical and chemical properties including outstanding thermal/photochemical stability, intense absorption/emission profiles, high photoluminescence quantum yield, and small Stokes' shifts. In addition to BODIPY, indole and its derivatives have recently gained attention because of their structural properties and particularly biological importance, therefore these molecules have been widely used in sensing and biosensing applications. Here, we focus on recent studies that reported the incorporation of indole‐based BODIPY molecules as reporter molecules in sensing systems. We highlight the rationale for developing such systems and evaluate detection limits of the developed sensing platforms. Furthermore, we also review the application of indole‐based BODIPY molecules in bioimaging studies. This article includes the evaluation of indole‐based BODIPYs from synthesis to characterization and a comparison of the advantages and disadvantages of developed reporter systems, making it instructive for researchers in various disciplines for the design and development of similar systems.     

刺楸年轮中重金属含量动态变化及富集特性

为探索刺楸对受污染土壤重金属的富集和修复效应, 以南京栖霞山的乡土树种刺楸及其根际周边土壤为研究对象, 截取其根基部年轮盘及根际土壤样本, 采用ICP-AES法测定年轮及土壤样本中重金属(Cu、Cd、Cr、Mn、Ni、Pb、Zn)元素含量。结果表明: 栖霞山样地中的土壤受Mn、Pb和Zn污染最为严重, 存在Cu、Cd、Mn、Pb、Zn元素的高度复合污染, Cd、Cr、Cu、Ni、Zn在土壤和年轮中存在相关性, Mn和Pb则没有表现出明显的相关性; 刺楸修复受Cd、Mn、Pb、Zn污染的土壤效果并不显著, 更适用于Cr、Cu、Ni污染的土壤修复; 鉴于Cu元素含量变化特征, 刺楸也可以作为反映当地污染历史的记录载体; 刺楸年轮中的重金属元素之间存在交互作用, 其中Cd与Zn元素含量高度相关(r=0.984, p<0.01), 在刺楸年轮吸收重金属元素的过程中, Cu与Cd、Cr、Mn、Zn元素具有协同作用, Mn元素对其他元素有一定的拮抗作用。     

Regional distribution characteristics and ecological risk assessment of heavy metal pollution of different land use in an antimony mining area – Xikuangshan,China

Abstract

Mining activities have introduced various heavy metals and metalloids to surrounding soil environments, causing adverse impacts to the ecological environment system. The extremely high concentration of various heavy metals and metalloids make the Xikuangshan (Hunan, China) an excellent model to assess their ecological risk. In this study, the soil samples from 26 locations of different land use methods in four areas (smelting area, road nearby ore, mining area, and ore tailing area) in Xikuangshan with different levels of various heavy metals and metalloids (Sb, As, Pb, and Cd) were analyzed; in addition, the index of geo-accumulation and the potential ecological risk index were used to evaluate ecological risk. The results showed that the average contents of Sb, As, Pb, and Cd in all soil samples were 4368.222?mg·kg^?1, 40.722?mg·kg^?1, 248.013?mg·kg^?1, and 40.941?mg·kg^?1, respectively, implying serious contamination of compound pollution of heavy metals in soil. The concentration of heavy metals in soil among smelting area, road nearby ore, mining area, and ore tailing area showed significant distribution characteristics of region because different mining activities such as smelting, mining, transportation, and stacking caused different pollution intensity. Moreover, the contents of Sb in soil samples decreased successively in residue field, wasteland, forestland, sediment, grassland, and vegetable field, and the contents of Sb in vegetable-field and ecological restoration grassland were relatively low, which indicate that the method of grassland ecological restoration is an effective method to control antimony pollution in soil. The results of ecological risk assessment showed that the antimony mining area was seriously polluted by Sb, As, Pb, and Cd, and had strong ecological risk, and Sb and Cd were the most important pollution factors, which indicated that the pollution of Sb and Cd should be a major concern of relevant departments of environment and health.     

Design and synthesis of amphiphilic 2-hydroxybenzylphosphonium salts with antimicrobial and antitumor dual action

Here we report the synthesis and biological evaluation of a series of new 2-hydroxybenzylphosphonium salts (QPS) with antimicrobial and antitumor dual action. The most active compounds exhibit antimicrobial activity at a micromolar level against Gram-positive bacteria Sa (ATCC 209p and clinical isolates), Bc (1–2 μM) and fungi Tm and Ca, and induced no notable hemolysis at MIC. The change in nature of substituents of the same length led to a drastic change of biological activity. Self-assembly behavior of the octadecyl and oleyl derivatives was studied. QPS demonstrated self-assembly within the micromolar range with the formation of nanosized aggregates capable of the solubilizing hydrophobic probe. The synthesized phosphonium salts were tested for cytotoxicity. The most potent salt was active against on M−Hela cell line with IC₅₀ on the level of doxorubicin and good selectivity. According to the cytofluorimetry analysis, the salts induced mitochondria-dependent apoptosis.