Latest ArticlesHypoxic tumor microenvironment is a major challenge for photodynamic therapy (PDT). To overcome this problem, PDT combined hypoxia-activated chemotherapy is a promising strategy for hypoxic cancer therapy. Herein, a multifunctional liposome (AQ4N-Ir1-sorafenib-liposome) is prepared by encapsulating a hypoxia-activated prodrug AQ4N, a photosensitizer iridium(Ⅲ) complex and hepatocellular carcinoma (HCC) targeting drug sorafenib, for synergistic therapy of HCC. Ir1-mediated PDT upon irradiation induces ROS generation and hypoxic environment, which leads to the disassembly of the liposome and activates the antitumor activity of AQ4N. Meantime, the co-delivered sorafenib could effectively target therapy of HCC. It is noted that ferroptosis mechanism is proved during the treatment. This work contributes to the design of hypoxia-responsive multifunctional liposome for combination of chemotherapy, targeting therapy and PDT. It is a promising strategy for hypoxic HCC therapy.
Traditional treatment processes cannot completely remove phosphonates in circulating cooling water by one-step method. Herein, we designed peroxymonosulfate/UV irradiation/hydrated zirconium oxide (PMS/UV/HZO) coupling process to enhance the phosphonates removal. In particular, nitrilotris-methylenephosphonic acid (NTMP) removal efficiency by PMS/UV/HZO process was much higher than that of PMS/UV process, UV/HZO process and other processes in comparison experiments. Specifically, almost 97.2% NTMP in water was degraded, and the total phosphorous (TP) reduced from 9.3 mg/L to 0.26 mg/L at pH 7 within 180 min. TP removal efficiency still reached above 90% after 5 cycles adsorption-desorption of HZO. Moreover, Cl¯, NO3¯ and SO42¯ ions all had negligible effect on NTMP removal. During the process, NTMP was first destroyed to form phosphates and other intermediates by the reactive oxygen species (ROS), then phosphates were in situ immobilized via HZO adsorption. Sulfate radical (SO4•−) has been confirmed to be the major ROS in the reaction system by quenching experiment and electron paramagnetic resonance (EPR) characterization. And the excellent selective adsorption capacity of HZO for phosphate produced was attributed to the strong inner-sphere coordination between H2PO4¯/HPO42¯ and Zr-OH on the surface of HZO. These results suggest that PMS/UV/HZO process is a promising technique for enhanced phosphonates decontamination.
Recently, MAX phases show great potential in lithium-ion uptake due to their excellent electrical conductivity and unique lamellar-structure accommodating lithium ions. However, the reports about MAX electrodes for lithium-ion battery up to now are relatively low. Herein we report the preparation of surface oxygen-deficient Ti2SC with abundant oxygen vacancies by a facile surface engineering method. When using as a lithium storage anode, this oxygen-deficient Ti2SC delivers a high capacity of 350 mAh/g at a current density of 400 mA/g as well as excellent rate performance, doubling the capacity compared to that of Ti2SC without oxygen vacancies. Confirmed by electrochemical impedance spectroscopy (EIS) and kinetic mechanism analyses, after reducing surface oxides and generation of oxygen vacancies, the as-received Ti2SC exhibits higher electrical conductivity and faster lithium ion diffusion. Thus this work offers a facial and effective strategy of optimizing the surface structure of MAX phases, further to achieve an enhanced lithium-ion uptake for lithium-ion batteries or capacitors.
Phthalates esters (PAEs) are extensively used as additives for polymers in plastic, particularly in polyvinyl chloride (PVC) and polyethylene terephthalate (PET). These compounds are not part of the polymer chains and can be released easily from products and migrate into beverages and foods that come into direct contact, causing environmental and human health impacts. Simple and rapid detection of such substances is of great significance for ensuring environmental food safety and consumer health. At present, optical sensor and electrochemical sensor detection technologies have been applied to PAEs detection due to their advantages, such as simple, rapid, low cost, high sensitivity, simple operation, portability and high specificity. They can make up for the shortcomings of chromatographic detection technology, such as expensive equipment, cumbersome operation, the need for professional and technical personnel, and difficulty in achieving a large number of sample screening objectives. In this paper, research progress on optical sensors and electrochemical sensors for the detection of phthalates in recent ten years is reviewed and discussed. This is helpful to better understand preparation methods for sensors and their detection mechanisms for phthalates. The review will also be used in developing a more effective trace detection sensor for phthalates.
Air-breathing proton exchange membrane fuel cells (PEMFCs) are very promising portable energy with many advantages. However, its power density is low and many additional supporting parts affect its specific power. In this paper, we aim to improve the air diffusion and fuel cell performance by employing a novel condensing-tower-like curved flow field rather than an additional fan, making the fuel cell more compact and has less internal power consumption. Polarization curve test and galvanostatic discharge test are carried out and proved that curved flow field can strengthen the air diffusion into the PEMFC and improve its performance. With appropriate curved flow field, the fuel cell peak power can be 55.2% higher than that of planar flow field in our study. A four-layer stack with curved cathode flow field is fabricated and has a peak power of 2.35 W (120 W/kg).
Graphite carbon nitride (g-C3N4) is a promising non-metal photocatalyst for photocatalytic hydrogen production, but its performance is still limited due to sluggish charges separation and low utilization of light. In this work, P-doped and N-doped carbon dots (NCDs) supported g-C3N4 were successfully prepared via hydrothermal and polymerization reactions. The sub-bandgap formed by P-doping enhances the utilization of visible light, and the high electron density of P sites is conducive to the trapping of holes. NCDs also improve light utilization and, more importantly, act as electron acceptors and transporters to promote electron transport. The built-in electric field formed by the synergy of P-doping and NCDs-loading greatly promotes the separation of charges. The PCN/NCDs showed a significantly improved hydrogen evolution activity of 3731 µmol h−1 g−1, which was 6.7 times that of pure carbon nitride (560 µmol h−1 g−1). This strategy may be generalized to the design of g-C3N4 -based photocatalysts, facilitating the separation of charges for enhanced catalytic activity.
Aqueous zinc ion batteries (AZIBs) with the merits of low cost, low toxicity, high safety, environmental benignity as well as multi-valence properties as the large-scale energy storage devices demonstrate tremendous application prospect. However, the explorations for the most competitive manganese-based cathode materials of AZIBs have been mainly limited to some known manganese oxides. Herein, we report a new type of cathode material NH4MnPO4·H2O (abbreviated as AMPH) for rechargeable AZIBs synthesized through a simple hydrothermal method. An in-situ electrochemical strategy inducing Mn-defect has been used to unlock the electrochemical activity of AMPH through the initial charge process, which can convert poor electrochemical characteristic of AMPH towards Zn2+ and NH4+ into great electrochemically active cathode for AZIBs. It still delivers a reversible discharge capacity up to 90.0 mAh/g at 0.5 A/g even after 1000th cycles, which indicates a considerable capacity and an impressive cycle stability. Furthermore, this cathode reveals an (de)insertion mechanism of Zn2+ and NH4+ without structural collapse during the charge/discharge process. The work not only supplements a new member for the family of manganese-based compound for AZIBs, but also provides a potential direction for developing novel cathode material for AZIBs by introducing defect chemistry.
Lithium rich layered oxide (LRLO) has been considered as one of the promising cathodes for lithium-ion batteries (LIBs). The high voltage and large capacity of LRLO depend on Li2MnO3 phase. To ameliorate the electrochemical performance of Li2MnO3, also written as Li(Li1/3Mn2/3)O2, we propose a strategy to substitute Mn4+ and Li+ in Mn/Li transition metal layer with Ti4+, which can stabilize the structure of Li2MnO3 by inhibiting the excessive oxidation of O2− above 4.5 V. More significantly, the unequal-valent substitution brings about the emergence of interlayer Li vacancies, which can promote the Li-ion diffusion based on the enlarged interlayer and increase the capacity by activating the Mn3+/4+ redox. We designed Li0.7[Li1/3Mn2/3]0.7Ti0.3O2 with high interlayer Li vacancies, which presents a high capacity (290 mAh/g at 10 mA/g) and stable cycling performance (84% over 60 cycles at 50 mA/g). We predict that this strategy will be helpful to further improve the electrochemical performance of LRLOs.
Crystalline porous ionic salts (CPISs) represent a new type of porous materials constructed by electrostatic interaction, however, synthesis of CPISs bearing pre-designed functionality while exhibiting permanent porosity is still challenging. Herein we report the facile synthesis of a series of CPISs 1-3 built from photocatalytic-active polyoxometalate (POM) clusters and cationic Zr-based capsules, which showed open porous frameworks with BET surface area up to 33 m2/g and high activity and selectivity for photo-driven aerobic oxidation of alcohols to aldehydes. Compared with the pristine POM cluster {W10}, 1 can promote the reaction in much higher efficiency due to the concerted catalysis of preinstalled {W10} and Zr-based capsule together with open channels. This work highlights the advantage of CPISs as porous heterogeneous catalysts in organic transformation, and may shed light on the rational design of more delicate CPISs-derived functional materials.
Sodium-ion batteries (SIB) have attracted widespread attention in large-scale energy storage fields owing to the abundant reserve in the earth and similar properties of sodium to lithium. Biomass-based carbon materials with low-cost, controllable structure, simple processing technology, and environmental friendliness tick almost all the right boxes as one of the promising anode materials for SIB. Herein, we present a simple novel strategy involving tea tomenta biomass-derived carbon anode with enhanced interlayer carbon distance (0.44 nm) and high performance, which is constructed by N, P co-doped hard carbon (Tea-1100-NP) derived from tea tomenta. The prepared Tea-1100-NP composite could deliver a high reversible capacity (326.1 mAh/g at 28 mA/g), high initial coulombic efficiency (ICE = 90% at 28 mA/g), stable cycle life (262.4 mAh/g at 280 mA/g for 100 cycles), and superior rate performance (224.5 mAh/g at 1400 mA/g). Experimental results show that the excellent electrochemical performance of Tea-1100-NP due to the high number of active N, P-containing groups, and disordered amorphous structures provide ample active sites and increase the conductivity, meanwhile, large amounts of microporous shorten the Na+ diffusion distance as well as quicken ion transport. This work provides a new type of N, P co-doped high-performance tomenta-derived carbon, which may also greatly promote the commercial application of SIB.