A Janus Separator based on Cation Exchange Resin and Fe Nanoparticles-decorated Single-wall Carbon Nanotubes with Triply Synergistic Effects for High-areal Capacity Zn-I2 Batteries.

Zn-I2 batteries stand out in the family of aqueous Zn-metal batteries (AZMBs) due to their low-cost and immanent safety. However, Zn dendrite growth, polyiodide shuttle effect and sluggish I2 redox kinetics result in dramatically capacity decay of Zn-I2 batteries. Herein, a Janus separator composed of functional layers on anode/cathode sides is designed to resolve these issues simultaneously. The cathode layer of Fe nanoparticles-decorated single-wall carbon nanotubes can effectively anchor polyiodide and catalyze the redox kinetics of iodine species, while the anode layer of cation exchange resin rich in -SO3 - groups is beneficial to attract Zn2+ ions and repel detrimental SO4 2- /polyiodide, improving the stability of cathode/anode interfaces synergistically. Consequently, the Janus separator endows outstanding cycling stability of symmetrical cells and high-areal-capacity Zn-I2 batteries with a lifespan over 2500 h and a high-areal capacity of 3.6 mAh cm-2 .

A DNA-functionalized biomass nanoprobe for the targeted photodynamic therapy of tumor and ratiometric fluorescence imaging-based visual cancer cell identification/antitumor drug screening.

Survivin is widely expressed in tumor tissue, in which the in situ ratiometric fluorescence imaging of intracellular survivin mRNA can provide accurate information for the diagnosis and treatment of cancers, as well as the screening of antitumor drugs. However, the development of a nanoprobe that can be used simultaneously in the diagnosis and treatment of tumors and the screening of antitumor drugs remains a challenge. In an effort to address these requirements, a multifunctional biomass nanoprobe was developed for the photodynamic therapy (PDT) of tumors as well as cancer cell identification and antitumor drug screening based on the ratiometric fluorescence imaging of intracellular survivin mRNA. This nanoprobe was assembled from near-infrared (NIR) biomass quantum dots (BQDs), single-stranded DNA and NIR dye (dylight680) labeled single-stranded DNA. The BQDs contain a large number of chlorophyll molecules, meaning that they can produce a large amount of singlet oxygen under NIR light irradiation, thus realizing the PDT of a tumor. However, the specific binding of the nanoprobe to intracellular survivin mRNA causes the release of dylight680 and reduces the fluorescence resonance energy transfer (FRET) efficiency between the BQDs and dylight680 in the probe, thereby achieving the ratiometric fluorescence imaging of survivin mRNA. Therefore, the prepared nanoprobe can not only be used in the diagnosis of cancers, but also in the targeted PDT of tumors.

Solvent-Induced Single Crystal-Single Crystal Transformation of an Interpenetrated Three-Dimensional Copper Triazole Catalytic Framework.

The 2-fold interpenetrated 3D framework 1 can be solvent-induced to noninterpenetrated framework 1' in a reversible single crystal-single crystal transformation fashion. In addition, 1' represents the first catalyst based on triazole to catalyze the aerobic homocoupling of various substituted arylboronic acids.

Simultaneous Inhibition of Zn Dendrites and Polyiodide Ions Shuttle Effect by an Anion Concentrated Electrolyte Membrane for Long Lifespan Aqueous Zinc-Iodine Batteries.

Aqueous zinc-iodine (Zn-I2) batteries have attracted extensive attention due to their merits of inherent safety, wide natural abundance, and low cost. However, their application is seriously hindered by the irreversible capacity loss resulting from both anode and cathode. Herein, an anion concentrated electrolyte (ACE) membrane is designed to manipulate the Zn2+ ion flux on the zinc anode side and restrain the shuttle effect of polyiodide ions on the I2 cathode side simultaneously to realize long-lifetime separator-free Zn-I2 batteries. The ACE membrane with abundant sulfonic acid groups possesses a multifunctional amalgamation of good mechanical strength, guided Zn2+ ion transport, and effective charge repulsion of polyiodide ions. Moreover, rich ether oxygen, carbonyl, and S-O bonds in anionic polymer chains will form hydrogen bonds with water to reduce the proportion of free water in the ACE membrane, inhibiting the water-induced interfacial side reactions of the Zn metal anode. Besides, DFT calculations and in-situ UV-vis and in situ Raman results reveal that the shuttle effect of polyiodide ions is also significantly suppressed. Therefore, the ACE membrane enables a long lifespan of Zn anodes (3700 h) and excellent cycling stability of Zn-I2 batteries (10000 cycles), thus establishing a substantial base for their practical applications.

Dynamically Interfacial pH-Buffering Effect Enabled by N-Methylimidazole Molecules as Spontaneous Proton Pumps toward Highly Reversible Zinc-Metal Anodes.

Aqueous zinc-metal batteries have attracted extensive attention due to their outstanding merits of high safety and low cost. However, the intrinsic thermodynamic instability of zinc in aqueous electrolyte inevitably results in hydrogen evolution, and the consequent generation of OH- at the interface will dramatically exacerbate the formation of dead zinc and dendrites. Herein, a dynamically interfacial pH-buffering strategy implemented by N-methylimidazole (NMI) additive is proposed to remove the detrimental OH- at zinc/electrolyte interface in real-time, thus eliminating the accumulation of by-products fundamentally. Electrochemical quartz crystal microbalance and molecular dynamics simulation results reveal the existence of an interfacial absorption layer assembled by NMI and protonated NMI (NMIH+ ), which acts as an ion pump for replenishing the interface with protons constantly. Moreover, an in situ interfacial pH detection method with micro-sized spatial resolution based on the ultra-microelectrode technology is developed to probe the pH evolution in diffusion layer, confirming the stabilized interfacial chemical environment in NMI-containing electrolyte. Accordingly, with the existence of NMI, an excellent cumulative plating capacity of 4.2 Ah cm-2 and ultrahigh Coulombic efficiency of 99.74% are realized for zinc electrodes. Meanwhile, the NMI/NMIH+ buffer additive can accelerate the dissolution/deposition process of MnO2 /Mn2+ on the cathode, leading to enhanced cycling capacity.

Near-Infrared Dual-Emission Ratiometric Fluorescence Imaging Nanoprobe for Real-Time Tracing the Generation of Endogenous Peroxynitrite in Single Living Cells and In Vivo.

Peroxynitrite (ONOO-) is a highly reactive nitrogen species with potent oxidant and nitrating properties. Its excessive generation can cause DNA and protein damage, thereby contributing to cell injury, and it is closely related to the development of many diseases. Thus, there is an urgent need for a reliable method to determine changes in the steady-state levels of ONOO- in vivo. Ratiometric imaging, due to its built-in self-calibration system, can reduce artifacts and enable reliable in vivo imaging. In this study, we designed and prepared near-infrared (NIR) biomass quantum dots (NI-BQDs) and covalently coupled them with the NIR dye Cyanine7 (Cy7) to construct an NIR dual-emission nanoprobe (NI-BQD-Cy7) for real-time tracing the generation of endogenous ONOO- in single living cells and in vivo by ratiometric fluorescence imaging. NI-BQD-Cy7 exhibited high detection sensitivity and selectivity for ONOO- in the mitochondria. Additionally, it can produce dual NIR fluorescence emission, thus allowing in situ ratiometric fluorescence imaging to real-time trace the generation and concentration changes of ONOO- in vivo. The application of the proposed NIR dual-emission nanoprobe can provide accurate information for the study of the biological function of ONOO- in single living cells and in vivo, and it is very useful to explain the mechanism of cell damage caused by ONOO-.