Latest ArticlesElectrochemical advanced oxidation processes (EAOPs) are effective and environmentally friendly for the treatment of refractory organic pollutants. Among EAOPs, heterogeneous electro-Fenton (EF) process with in-situ formation of hydrogen peroxide (H2O2) is an eco-friendly, cost-effective and easy-operable technology to generate hydroxyl radicals (·OH) with high redox potential. The generation of ·OH is determined by the synergistic H2O2 formation and activation. The surface catalytic mechanisms for H2O2 activation in the heterogeneous EF process were discussed. Some required features such as heteroatom doping and oxygen groups for H2O2 formation via selective two-electron oxygen reduction reaction (ORR) with carbonaceous electrode are summarized. The solid Fenton catalysts and integrated functional cathodes that widely used in heterogeneous EF for wastewater treatment are grouped into few classes. And the brief discussion on catalytic activity and stability of materials over different experimental conditions are given. In addition, the application of heterogeneous EF process on the remediation of emerging contaminants is provided. The challenges and future prospects of the heterogeneous EF processes about catalytic fall-off and multi-step/complex techniques for water purification are emphasized.
To lower the operation temperature and increase the durability of solid oxide fuel cells (SOFCs), increasing attentions have been paid on developing cathode materials with good oxygen reduction reaction (ORR) activity at intermediate-temperature (IT, 500–750 ℃) range. However, most cathode materials exhibit poor catalytic activity, or they thermally mismatch with SOFC electrolytes and undergo severe degeneration. Infiltrating catalysts on existing backbone materials has been proved to be an efficient method to construct highly active and durable cathodes. In this mini-review, the advantages of infiltration-based cathode compared with new material-based cathodes are summarized. The merits and drawbacks of different backbones are illustrated. Different types of catalysts for infiltration are depicted in detail. Suggestions on the material/structure optimization of the infiltrated cathodes of IT-SOFC are provided.
Efficient bifunctional OER/ORR catalysts are crucial for the further development of zinc-air battery. From a sustainable point of view, it is important that electrocatalysts are efficient, low cost, and composed of abundant resources instead of scarce metals. Due to their good conductivity, low cost, and strong durability, carbon-based materials are considered a promising alternative in the field of commercial zinc-air battery catalysts. Herein, we briefly introduce the zinc-air battery and then summarize recent progress in the development of carbon-based bifunctional catalysts by defect engineering, heteroatom doping and metal doping. Finally, we discuss the main challenges and prospects for the future development of carbon-based bifunctional oxygen catalysts.
As emerging two-dimensional materials, metal-organic framework (MOF) nanosheet composites possess many unique physical and chemical properties, thus being expected to be widely applied in gas separation and adsorption, energy conversion and storage, heterogeneous catalysis, sensing as well as biomedicine. In this review, we first introduce the methods for integrating MOF nanosheets with other materials to prepare multifunctional composites. Next, the applications of MOF nanosheet composites in versatile fields are summarized and discussed. We hope this review will be instructive for researchers in the aspects of designs, preparations and applications of MOF nanosheet composites.
Graphene-based sponge is a novel hemostatic material prepared by chemical cross-link of graphene oxide. It has a fast fluid absorption capacity to quickly absorb blood from wounds, activate clotting pathways, and achieve rapid hemostasis. In addition, graphene-based sponge is also a good platform carrier. It can be prepared by organic cross-linking, compounding with inorganic clay, and adding bioactive factors to enhance coagulation stimulation. By these methods, the hemostatic performance of the sponge is further improved, which shows great potential for application in the field of trauma hemostasis. This article reviews the research progress of graphene-based sponges from three different preparation strategies (organic cross-linking, inorganic compounding and adding bioactive factor), summarizes their hemostatic mechanisms, and prospects the development of graphene-based hemostatic sponges.
Transition metal oxides (TMO) bring a novel direction for the development of energy store materials due to their excellent stability. They not only have high capacity and good cycle performance, but also are cheap and easily available. Zinc oxide (ZnO) as an important part of TMO have gradually attracted attention in the research of electrochemistry. ZnO, as a metal semiconductor with the advantages of wide band gap, possesses high ion migration rate, good chemical stability, simple preparation and low cost, and is widely used in various fields. However, poor conductivity, low permittivity and quick capacity decays quickly impede the commercial application of these electrodes. In recent years, in order to improve the structural stability, ion diffusion and conductivity of zinc oxides-based anodes, various strategies have been raised, such as structural design, surface modification and composition control. In this paper, the recent advances of zinc oxides-based materials for batteries and hybrid supercapacitors (SCs) were introduced. We comprehensively reviewed the prepared process, reaction mechanism and electrochemical performance and discussed the shortcoming of zinc oxides-based nanomaterials. In particular, several insights toward the future research development, practical applications and commercialization of energy storage devices are also proposed for improving the performance of zinc oxides-based materials.
Sodium-ion batteries (SIBs) have gained more scientists' interest, owing to some facts such as the natural abundance of Na, the similarities of physicochemical characteristics between Li and Na. The irreversible Na+ ions consumption during the first cycle of charge/discharge process (due to the formation of the solid electrolyte interface (SEI) on the electrode surface and other irreversible reactions) is the factor that determines high performance SIBs and largely reduces the capacity of the full cell SIBs. Thus, the initial coulombic efficiency (ICE) of SIBs for both anode and cathode materials, is a key parameter for high performance SIBs, and the point is to increase the transport rate of the Na+ ions. Therefore, developing SIBs with high ICE and rate performance becomes vital to boost the commercialization of SIBs. Here we provide a review on the methods to improve the ICE and the rate performance, by summarizing some methods of improving the ICE and rate performance of the anode and cathode materials for SIBs, and end by a conclusion with some perspectives and recommendations.
Chemiluminescence immunoassay (CLIA) has always been a great challenge in detecting cardiac troponin I (cTnI) in whole blood samples without centrifugation because of the interference of red blood cells and low sensitivity. In this study, the antigens and erythrocytes in the blood were captured by the antibodies immobilized on the magnetic particles, recognized by another biotin-conjugated cTnI antibody and detected by streptavidin/acridine aster-conjugated polychloromethylstyrene microspheres (PCMS). After magnetic separation, the supernatant was transferred and measured. No significant difference was noted between the cTnI concentrations of the serum samples, plasma samples and whole blood. The prepared PCMS provided more functional areas to conjugate streptavidin and acridinium ester, so the immunoassay has highly sensitive, the limits of blank at 0.012 ng/mL, and functional sensitivity at 0.019 ng/mL with a CV of 20%, and 0.058 ng/mL with a CV of 10%. Total precision of any sample type ranged from 2.62%~5.67%. The assay was linear over the studied range of 0.01-50.00 ng/mL, and no hook effect was found when cTnI concentrations reached 1900 ng/mL. No significant interference was noted with the potential endogenous interfering substances. Compared with the commercial kit (Abbott assay kit), the correlation coefficient was 0.9859. A washing-free CLIA was established for the rapid detection of cTnI in human whole blood, using erythrocyte capture antibodies-conjugated magnetic nanoparticles for eliminating the influence of erythrocytes and PCMS for signal amplification, which showed great potential in clinical application.
Current resolved structures of GPCRs and G protein complexes provided important insights into G protein activation. However, the binding or dissociation of GPCRs with G protein is instantaneous and highly dynamic in the intracellular environment. The conformational dynamic of G protein still needs to be addressed. In this study, we applied 19F solution NMR spectroscopy to monitor the conformational changes of G protein upon interact with detergent mimicking membrane and receptor. Our results show that there are two states equilibria in the Gα in apo states. The interaction of Gα with detergents will accelerate this conformational transformation and induce a state that tends to bind to GPCRs. Finally, the Gα proteins presented a fully activation state when they coupled to GPCRs.