RESUMO
Aqueous Zn battery has been a promising alternative battery in large-scale energy storage systems due to its cost-effectiveness, sustainability, and intrinsic safety. However, its cycle life is impeded by the dendrite formation, severe corrosion, and side reactions on the zinc metal anode. Most ex situ coatings on the zinc surface extend the life span of zinc anodes but have drawbacks in Zn2+ ion conductivity. Herein, a robust sodium zinc phosphate layer was in situ built on zinc metal foil anode (Zn@NZP) via facile electrodeposition. The Zn2+ ion conducting protection layer alleviates corrosion, suppresses zinc dendrites, and lowers the energy barrier of Zn2+ plating and stripping. As a result, the Zn@NZP anode renders dendrite-free plating/stripping with a small overpotential of about 44 mV and a 12-fold enhancement long-life span compared to the bare zinc. Furthermore, a full cell using the Zn@NZP anode shows much improved capacity and cycling stability. This work provides a promising anode candidate for dendrite-free aqueous zinc ion batteries.
RESUMO
Hydrated V2O5 with unique physical and chemical characteristics has been widely used in various function devices, including solar cells, catalysts, electrochromic windows, supercapacitors, and batteries. Recently, it has attracted extensive attention because of the enormous potential for the high-performance aqueous zinc ion battery cathode. Although great progress has been made in developing applications of hydrated V2O5, little research focuses on improving current synthesis methods, which have disadvantages of massive energy consumption, tedious reaction time, and/or low efficiency. Herein, an improved synthesis method is developed for hydrated V2O5 nanoflakes according to the phenomenon that the reactions between V2O5 and peroxide can be dramatically accelerated with low-temperature heating. Porous hydrated V2O5 nanoflake gel was obtained from cheap raw materials at 40 °C in 30 min. It shows a high specific capacity, of 346.6 mAh/g, at 0.1 A/g; retains 55.2% of that at 20 A/g; and retains a specific capacity of 221.0 mAh/g after 1800 charging/discharging cycles at 1 A/g as an aqueous zinc ion battery cathode material. This work provides a highly facile and rapid synthesis method for hydrated V2O5, which may favor its applications in energy storage and other functional devices.
RESUMO
A highly sensitive Tb(3+) complex-based luminescent probe, N,N,N(1),N(1)-[2,6-(3'-aminomethyl-1'-pyrazolyl)-4-(3'',4''-diaminophenoxy)methylene-pyridine] tetrakis(acetate)-Tb(3+) (BMTA-Tb(3+)), has been designed and synthesized for the recognition and detection of hydrogen peroxide (H(2)O(2)) in aqueous solutions. This probe is almost nonluminescent because the Tb(3+) luminescence is effectively quenched by the electron-rich moiety, diaminophenyl, on the basis of the photoinduced electron transfer (PET) mechanism. In the presence of peroxidase, the probe can react with H(2)O(2) to cause the cleavage of the diaminophenyl ether, which affords a highly luminescent Tb(3+) complex, N,N,N(1),N(1)-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-hydroxymethyl-pyridine] tetrakis(acetate)-Tb(3+) (BHTA-Tb(3+)), accompanied by a 39-fold increase in luminescence quantum yield with the increase of luminescence lifetime from 1.95 to 2.76 ms. The dose-dependent luminescence enhancement of the probe shows a good linearity with a detection limit of 3.7 nM for H(2)O(2), which is approximately 14-fold lower than those of the commonly used fluorescent probes. The probe was used for the time-resolved luminescence imaging detection of the oligosaccharide-induced H(2)O(2) generation in tobacco leaf epidermal tissues. On the basis of the probe, a background-free time-resolved luminescence imaging method for detecting H(2)O(2) in complicated biological systems was successfully established.
Assuntos
Complexos de Coordenação/química , Corantes Fluorescentes/química , Peróxido de Hidrogênio/metabolismo , Medições Luminescentes/métodos , Nicotiana/metabolismo , Térbio/química , Complexos de Coordenação/síntese química , Transporte de Elétrons , Peroxidases/metabolismo , Folhas de Planta/metabolismoRESUMO
Time-resolved (or time-gated) luminescence detection technique using lanthanide chelates as luminescent probes is a widely used and highly sensitive method for the biological applications. The developments of various functional lanthanide probes that can selectively recognize the biological targets are the essential objective of the technique. In this work, a unique Tb(3+) chelate-based luminescent probe, N,N,N(1),N(1)-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-(p-aminophenoxy)methylene-pyridine] tetrakis(acetate)-Tb(3+)(BMPTA-Tb(3+)), has been designed and synthesized for highly selective and sensitive time-resolved luminescence detection of one highly reactive oxygen species (ROS), hydroxyl radical (OH). The probe is almost non-luminescent, and can selectively react with hydroxyl radical to afford a highly luminescent Tb(3+) chelate, N,N,N(1),N(1)-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-hydroxymethyl-pyridine] tetrakis(acetate)-Tb(3+) (BHTA-Tb(3+)), accompanied by a 49-fold increase in luminescence quantum yield with a long luminescence lifetime (2.76 ms). The luminescence response of the probe to hydroxyl radical is highly selective and insensitive to pH in the physiological pH range. For loading the probe into the living cells, the acetoxymethyl ester of BMPTA-Tb(3+) was synthesized and used for the HeLa cell loading. Based on this probe, a background-free time-resolved luminescence imaging method for detecting hydroxyl radical in living cells was successfully established.
RESUMO
Time-resolved luminescence detection technique using lanthanide chelates as luminescent probes or sensors is a highly sensitive and widely used tool for the luminescence detections of various biological and bioactive molecules. The essential of this technique is the developments of various functional luminescent probes or sensors that can selectively recognize the biological targets. In this work, a dual-chelating ligand N,N,N(1),N(1)-{2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-[N,N-bis(2-picolyl)amino-methylenepyridine]} tetrakis(acetic acid) (BBATA) has been designed and synthesized. The luminescence of its Tb(3+) chelate is very weak, but can be selectively and strongly enhanced upon reaction with Zn(2+) ions. Thus a Tb(3+) chelate-based luminescent chemosensor, BBATA-Tb(3+), for highly selective and sensitive time-resolved luminescence detection of Zn(2+) ions was developed. To confirm the utility of new chemosensor for the detection of intracellular Zn(2+) ions, the performance of BBATA-Tb(3+) as a chemosensor for time-resolved luminescent imaging detection of Zn(2+) ions in living cells was investigated. The results demonstrated the efficacy and advantage of the new luminescent chemosensor for time-resolved luminescence detection of intracellular Zn(2+) ions.