Tumour microenvironment-responded Fe-doped carbon dots-sensitized cubic Cu2O for Z-scheme heterojunction-enhanced sono-chemodynamic synergistic tumor therapy.

The efficacy of electron-hole separation in a single sonosensitizer and the complexities of the tumor microenvironment (TME) present significant challenges to the effectiveness of sonodynamic therapy (SDT). Designing efficient sonosensitizers to enhance electron-hole separation and alleviate TME resistance is crucial yet challenging. Herein, we introduce a novel Z-scheme heterojunctions (HJs) sonosensitizer using Fe-doped carbon dots (CDs) as auxiliary semiconductors to sensitize cubic Cu2O (Fe-CDs@Cu2O) for the first time. Fe-CDs@Cu2O demonstrated enhanced SDT effects due to improved electron-hole separation. Additionally, the introduction of Fe ions in CDs synergistically enhances Fenton-like reactions with Cu ions in Cu2O, resulting in enhanced chemodynamic therapy (CDT) effects. Moreover, Fe-CDs@Cu2O exhibited rapid glutathione (GSH) depletion, effectively mitigating TME resistance. With high rates of 1O2 and OH generated by Fe-CDs@Cu2O, coupled with strong GSH depletion, single drug injection and ultrasound (US) irradiation effectively eliminate tumors. This innovative heterojunction sonosensitizer offers a promising pathway for clinical anti-tumor treatment.

A Sonoresponsive and NIR-II-Photoresponsive Nanozyme for Heterojunction-Enhanced "Three-in-One" Multimodal Oncotherapy.

Although low-cost nanozymes with excellent stability have demonstrated the potential to be highly beneficial for nanocatalytic therapy (NCT), their unsatisfactory catalytic activity accompanied by intricate tumor microenvironment (TME) significantly hinders the therapeutic effect of NCT. Herein, for the first time, a heterojunction (HJ)-fabricated sonoresponsive and NIR-II-photoresponsive nanozyme is reported by assembling carbon dots (CDs) onto TiCN nanosheets. The narrow bandgap and mixed valences of Ti3+ and Ti4+ endow TiCN with the capability to generate reactive oxygen species (ROS) when exposed to ultrasound (US), as well as the dual enzyme-like activities of peroxidase and glutathione peroxidase. Moreover, the catalytic activities and sonodynamic properties of the TiCN nanosheets are boosted by the formation of HJs owing to the increased speed of carrier transfer and the enhanced electron-hole separation. More importantly, the introduction of CDs with excellent NIR-II photothermal properties could achieve mild hyperthermia (43 °C) and thereby further improve the NCT and sonodynamic therapy (SDT) performances of CD/TiCN. The synergetic therapeutic efficacy of CD/TiCN through mild hyperthermia-amplified NCT and SDT could realize "three-in-one" multimodal oncotherapy to completely eliminate tumors without recurrence. This study opens a new avenue for exploring sonoresponsive and NIR-II-photoresponsive nanozymes for efficient tumor therapy based on semiconductor HJs.

Encapsulation of BiOCl nanoparticles in N-doped carbon nanotubes as a highly efficient anode for potassium ion batteries.

With gradually increasing cost and shrinking crustal abundance for lithium ion batteries (LIBs), it is necessary to develop potassium ion batteries (PIBs) and explore suitable electrode materials for advanced PIBs. In this work, nanoscale BiOCl nanoparticles encapsulated in N-doped carbon nanotubes (BiOCl@N-CNTs) are designed and used as the anode material for K ion storage. The BiOCl@N-CNT composite is composed of BiOCl nanoparticles (≈ 5 nm) and N-doped carbon nanotubes. The ultralsmall BiOCl nanoparticles offer excellent electrochemical activity for K ion storage and short ion diffusion path for rapid reaction kinetics, while the outer layer of N-CNTs can effectively improve the conductivity and provide space to accommodate volume expansion. Due to this synergistic effect of small size and a highly conductive skeleton, the BiOCl@N-CNT composite delivers good rate capability and long-term cycling stability when evaluated as an anode for PIBs. The special structure of embedding ultrasmall active materials with high performance in highly conductive N-CNTs represents an effective way of improving the activity of the electrode material, facilitating ion/charge transfer, and alleviating volume change towards excellent energy storage technology.

Agaric-like cobalt diselenide supported by carbon nanofiber as an efficient catalyst for hydrogen evolution reaction.

We synthesized herein a novel 3D cathode constructed by growing cobalt diselenide in situ on the surface of carbon nanofiber for hydrogen evolution reaction. The cobalt diselenides with two typical morphologies (agaric-like and nanorod-like) were synthesized by precisely controlling reaction time and temperature in the same system. They show excellent electrocatalytic performance for hydrogen evolution reactions. Especially, the agaric-like diselenide cobalt electrode has the low overpotential (187 and 199 mV) to obtain the current density of 50 and 100 mA cm-2 with a small Tafel slope of 37 mV dec-1 in acidic medium. The excellent catalytic performance of the agaric-like cobalt diselenide can be attributed to its large specific surface area and fast electron transfer rate. More importantly, the agaric-like cobalt diselenide supported carbon nanofiber electrode has excellent long-term stability in electrolyte. The outstanding electrocatalytic performance and stability of agaric-like cobalt diselenide supported carbon nanofiber indicate that it is a promising electrocatalyst for hydrogen evolution reactions.

Effect of the Transition Metal Ions on the Single-Molecule Magnet Properties in a Family of Air-Stable 3d-4f Ion-Pair Compounds with Pentagonal Bipyramidal Ln(III) Ions.

Single-molecule magnets (SMMs) are expected to be promising candidates for the applications of high-density information storage materials and quantum information processing. Lanthanide SMMs have attracted considerable interest in recent years due to their excellent performance. It has always been interesting but not straightforward to study the relaxation and blocking mechanisms by embedding 3d ions into 4f SMMs. Here we report a family of air-stable 3d-4f ion-pair compounds, YFe (1), DyCr (2), DyFe (3), DyCo (4), and Dy0.04Y0.96Fe (5), composed of pentagonal bipyramidal (D5h) LnIII cations and transition metallocyanate anions. The ion-pair nature makes the dipole-dipole interactions almost the only component of the magnetic interactions that can be clarified and analytically resolved under proper approximation. Therefore, this family provides an intuitive opportunity to investigate the effects of 3d-4f and 4f-4f magnetic interactions on the behavior of site-resolved 4f SMMs. Dynamic magnetic measurements of 1 under a 4 kOe external field reveal slow magnetic relaxation originating from the isolated [FeIII]LS (S = 1/2) ions. Under zero dc field, compounds 2-5 show similar magnetic relaxation processes coming from the separated pentagonal bipyramidal (D5h) DyIII ions with high Orbach barriers of 592(5), 596(4), 595(3), and 606(4) K, respectively. Comparatively, both compounds 3 and 5 exhibit two distinct relaxation processes, respectively from the [FeIII]LS and DyIII [Ueff = 596(4) K for 3 and 610(7) K for 5] ions, under a 4 kOe dc field. The dipolar interactions between the neighboring TMIII (TM = transition metal, CrIII or [FeIII]LS) and DyIII ions were revealed to have little effect on the thermal relaxation in compounds 2, 3, and 5, or the coexistence of the two separate relaxation processes in compounds 3 and 5 under a 4 kOe dc field, but they significantly affect the quantum tunneling of magnetization and the magnetic hysteresis behavior of 2 and 3 at low temperatures compared to those of 4.

Synthesis, Doping and Electrochemical Properties of Zn3V3O8.

The Zn3V3O8 was synthesized by solvothermal method combined with heat treatment using Zn(NO3)3 · 6H2O and NH4VO3 as raw materials. The Zn3V3O8 was doped by Co2+ to form Zn2.88Co0.12V3O8. The samples were characterized by X-ray diffraction and scanning electron microscopy techniques. Electrochemical tests showed that the initial discharge specific capacity for Zn2.88Co0.12V3O8 was 640.4 mAh·g-1 when the current density was 100 mA·g-1, which was higher than that of pure Zn3V3O8 (563.5 mAh · g-1). After 80 cycles, the discharge specific capacity of Zn2.88Co0.12V3O8 could maintain at 652.2 mAh · g-1, which was higher than that of pure Zn3V3O8 (566.8 mAh·g-1) under same condition. The Zn2.88Co0.12V3O8 owned better rate performances than those of pure Zn3V3O8 also. The related modification mechanisms were discussed in this paper.

Enhanced the photoelectrochemical performance of Bi2XO6 (X = W, Mo) for detecting hexavalent chromium by modification of CuS.

In this work, Bi2XO6 (X = W, Mo) are synthesized at different temperatures. The results of tests find the optimal temperatures of Bi2WO6 and Bi2MoO6 are 180 and 160°C (BW-180, BM-160). Then, BW-180 and BM-160 are further compounded with different contents of CuS. The results of photoelectrochemical (PEC) tests show that CuS can improve the PEC performance of semiconductor materials, and it has better performance when CuS mass fraction is 5%. These maybe the photoelectron potentials generated by CuS/Bi2XO6 (X = Mo, W) heterojunction reduce the combination of photogenerated electrons and holes. When the PEC sensor based on 5%-CuS/BW-180 detects Cr(VI), it has a linear range of 1-80 µmol/L with detection limit of 0.95 µmol/L, while the PEC sensor based on 5%-CuS/BM-160 detects Cr(VI) has a linear range of 0.5-230 µmol/L and a detection limit of 0.12 µmol/L. Thus, 5%-CuS/Bi2XO6 has potential application in hexavalent chromium detection.

Synthesis of Tin Oxide/Sponge Carbon Composite as Anode Material for Lithium-Ion Battery.

Tin oxide/sponge carbon composite (SnO2/C) is synthesized by solvothermal reaction. The expected electrode materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectrum. Related electrochemical properties are carried out by battery comprehensive testing system. The composite could remain its specific capacity at 660.5 mAh g-1 after 200 cycles and behaved superior rate performance. The experimental results show that SnO2/C composite not only owned improved conductivity but also stable frame structure during lithiation/delithiation processes. So SnO2/C composite behaved higher reversible specific capacity and rate performance than those of pure SnO2 or SnC2O4. Based on its outstanding electrochemical performances, the SnO2/C anode electrode is a hopeful candidate for future application in lithium ion battery system.

Synthesis and Electrochemical Properties of Germanium (Ge) Nanoparticles/Multiwalled Carbon Nanotubes Composite as Anode Material for Lithium Battery.

Germanium (Ge) nanoparticles/multiwalled carbon nanotubes (Ge/MWCNTs) composite is synthesized by solvothermal method combined with heat treatment under H2 atmosphere. The Ge particles are buried in MWCNTs network to form expected composite. The MWCNTs not only improve the conductivity of the composite but also act as a flexible matrix to buffer the volume change of germanium nanoparticles during the process of insertion and de-insertion in lithium ion battery system. The Ge/MWCNTs composite behaves better cycle performance and higher rate capability than those of pure germanium (Ge) nanoparticles. The Ge/MWCNTs maintained discharge capacity as 1040 mAh·g-1 after 60 cycles at the current density of 100 mA·g-1. It is a promising anode material for lithium ion battery application.

Synthesis and Electrochemical Properties of CoMn2O4 as Novel Material for Lithium Ion Battery Application.

The pure phase CoMn2O4 samples are successfully prepared by solvothermal method combined with calcination at different temperatures (600, 700 and 800 °C). The structure and morphology for CoMn2O4 samples are characterized by X-ray diffraction (XRD) and Scanning electron microscopy (SEM) techniques. The electrochemical properties for different samples were tested by battery testing system and electrochemical workstation. The results showed that the calcination temperatures have important effects on their electrochemical properties. The sample synthesized at 600 °C (CMO-600) exhibits uniform microspheres composed of some nano-particles. As a novel anode material for lithium-ion batteries (LIBs). The CMO-600 has a reversible specific capacity of 1270 mA g-1 retained after 100 circles at current density of 100 mA g-1 under a potential window from 3.0 to 0.01 V (vs. Li+/Li). It exhibits both high reversible capacity and good rate performance. So CMO-600 is a promising anode material for lithium ion battery application.

Simultaneous determination of heavy metals by an electrochemical method based on a nanocomposite consisting of fluorinated graphene and gold nanocage.

Fluorinated graphene/gold nanocage (FGP/AuNC) nanocomposite was developed for simultaneous determination of heavy metals using square wave anodic stripping voltammetry. Under optimized conditions, with a buffer pH of 5.0, a deposition potential of - 1.25 V, and a deposition time of 140 s, the method can obtain the best results. The FGP/AuNC electrode exhibits low limits of detection (0.08, 0.09, 0.05, 0.19, 0.01 µg L-1), wide linear ranges (6-7000, 4-6000, 6-5000, 4-4000, 6-5000 µg L-1), and well-separated stripping peaks (at - 1.10, - 0.77, - 0.50, - 0.01, 0.31 V vs Ag/AgCl) towards Zn2+, Cd2+, Pb2+, Cu2+, and Hg2+, respectively. Furthermore, the FGP/AuNC electrode is also used for simultaneous determination of Zn2+, Cd2+, Pb2+, Cu2+, and Hg2+ in real samples (peanut, rape bolt, and tea). Highly consistent results are found between the electrochemical method and atomic fluorescence spectrometry/inductively coupled plasma-mass spectrometry. The method has been successfully applied to the determination of heavy metal ions in agricultural food. Graphical abstract Schematic representation of simultaneous determination of heavy metal ions by electrochemical method. The FGP/AuNC (fluorinated graphene/gold nanocage) electrode is used to simultaneous determination of Zn2+, Cd2+, Pb2+, Cu2+, and Hg2+ by square wave anode stripping voltammetry.

1-(2-Cyanoethyl)pyrrole enables excellent battery performance at high temperature via the synergistic effect of Lewis base and C[triple bond, length as m-dash]N functional groups.

The electrolyte of a lithium ion battery is unstable and is easily decomposed at high temperature, which can lead to the degradation of battery performance. To solve this problem, herein a novel electrolyte additive 1-(2-cyanoethyl)pyrrole (CP) has been proposed to improve the electrochemical performance of LiFePO4 batteries at high temperature. The capacity retention of the battery with 1 wt% CP is 76.7%, while that of the battery without the additive is 38.1% after 200 cycles at 60 °C. Theoretical calculation results reveal that the binding energy of CP and PF5/HF is much higher than that of the solvents in the electrolyte. Surface analysis of the electrodes demonstrates that CP can reduce the decomposition of the electrolyte, and restrain the dissolution of transition metals in the electrolyte at high temperature. TEM/XPS results indicate that CP can modify the protective film on the surface of the cathode material and promote the formation of more regular and thinner CEI films. The promotion of the CP additive is of great significance for improving the high temperature performance of lithium ion batteries and is expected to be applied on a large scale.

Synthesis and Electrochemical Properties of Bi2MoO6/Carbon Anode for Lithium-Ion Battery Application.

High capacity electrode materials are the key for high energy density Li-ion batteries (LIB) to meet the requirement of the increased driving range of electric vehicles. Here we report the synthesis of a novel anode material, Bi2MoO6/palm-carbon composite, via a simple hydrothermal method. The composite shows higher reversible capacity and better cycling performance, compared to pure Bi2MoO6. In 0-3 V, a potential window of 100 mA/g current density, the LIB cells based on Bi2MoO6/palm-carbon composite show retention reversible capacity of 664 mAh·g-1 after 200 cycles. Electrochemical testing and ab initio density functional theory calculations are used to study the fundamental mechanism of Li ion incorporation into the materials. These studies confirm that Li ions incorporate into Bi2MoO6 via insertion to the interstitial sites in the MoO6-layer, and the presence of palm-carbon improves the electronic conductivity, and thus enhanced the performance of the composite materials.

Synthesis and Electrochemical Properties of CuC2O4·xH2O and CuC2O4·xH2O/Carbon Nanotubes (CNTs) Anodes for Lithium-Ion Batteries.

Pure CuC2O4·xH2O and CuC2O4·xH2O/carbon nanotubes (CNTs) composites are synthesized by a low-temperature hydrothermal process. The structure and morphology of the products are analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG) and Raman spectrum. The results demonstrate that the as-prepared CuC2O4·xH2O takes on a microsphere-like morphology, all CuC2O4·xH2O/CNTs nanocomposites are constructed by the intertwining of tabular CuC2O4·xH2O nanoparticles (NPs) and CNTs to form a tanglesome net. When evaluated as an anode materials for lithium ion batteries (LIBs), all CuC2O4·xH2O/CNTs electrodes possess higher reversible discharge capacities (more than 1000 mAh g-1) than the pure CuC2O4·xH2O, up to 200th cycle at a current density of 100 mA g-1. The results illustrate that the addition of CNTs can enhance the electrochemical performance of CuC2O4·xH2O. Overall, CuC2O4·xH2O/CNTs composite can be a promising candidate used as a promising anode for LIBs.

Synthesis of MoO3/V2O5/C Composite as Novel Anode for Li-Ion Battery Application.

The MoO3/V2O5/C, MoO3/C and V2O5/C are synthesized by electrospinning combined with heat treatment. These samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and thermogravimetric analysis (TG) techniques. The results show that sample MoO3/V2O5/C is a composite composed from MoO3, V2O5 and carbon. It takes on morphology of the nanofibers with the diameter of 200~500 nm. The TG analysis result showed that the carbon content in the composite is about 40.63%. Electrochemical properties for these samples are studied. When current density is 0.2 A g-1, the MoO3/V2O5/C could retain the specific capacity of 737.6 mAh g-1 after 200 cycles and its coulomb efficiency is 92.99%, which proves that MoO3/V2O5/C has better electrochemical performance than that of MoO3/C and V2O5/C. The EIS and linear Warburg coefficient analysis results show that the MoO3/V2O5/C has larger Li+ diffusion coefficient and superior conductivity than those of MoO3/C or V2O5/C. So MoO3/V2O5/C is a promising anode material for lithium ion battery application.

Low-Cost Ni2P/Ni0.96S Heterostructured Bifunctional Electrocatalyst toward Highly Efficient Overall Urea-Water Electrolysis.

Water splitting is a sustainable approach for production of hydrogen to fuel some clean energy technologies. This process, unfortunately, has been significantly impeded by the puzzles in either the efficient but economically unaffordable noble-metal-based catalysts or the low-cost but kinetically sluggish abundant-element-based catalysts. Particularly, the discovery of efficient bifunctional catalysts that can simultaneously trigger the reactions of both anode and cathode for overall water splitting still remains as a grand challenge. Herein, a novel low-cost bifunctional Ni2P/Ni0.96S heterostructured electrocatalyst, which is active for both the urea oxidation reaction at the anode and the hydrogen evolution reaction at the cathode, is innovated for high-efficiency overall splitting of urea-rich wastewater. A systematic configuration of a Ni foam (NF)-supported Ni2P/Ni0.96S catalyst electrode exhibits superior catalytic activity and stability. The Ni2P/Ni0.96S/NF||Ni2P/Ni0.96S/NF cell needs only 1.453 V to reach a current density of 100 mA/cm2 in basic urea-containing water, while it is 1.693 V for a reference noble-based Pt/C/NF||IrO2/NF electrolysis cell. This work therefore not only contributes to develop a low-cost, high-efficiency, bifunctional electrocatalyst but also provides a practically feasible approach for urea-rich wastewater treatment.

Synthesis of Ni/NiO@MIL-101(Cr) Composite as Novel Anode for Lithium-Ion Battery Application.

The poor conductivity is one of the prime reasons restricted MOFs to be applied in the lithium-ion battery system. For the sake of ameliorate this issue, the Ni/NiO was well loaded on the surface of Cr-based metal organic frameworks (MIL-101) by solution impregnation and in situ reduction method to form Ni/NiO@MIL-101(Cr) composites. The as-synthesized Ni/NiO@MIL-101(Cr) was characterized by X-ray powder diffractions, X-ray photoelectron spectroscopy, field emission scanning electron microscope and transmission electron microscope techniques. When used as anode for LIBs, the Ni/NiO@MIL-101(Cr) composite exhibited high reversible capacity (891 mAh g-1 after 100 cycles at a current density of 200 mA g-1) and stable cycle performance, the coulombic efficiency can maintain in the whole cycle above 95.0%. The reasons for that Ni/NiO@MIL-101(Cr) behaved outstanding electrochemical properties were discussed also. The Ni/NiO@MIL-101(Cr) can be used as promising material for lithium-ion battery application.

Visible light driven photoelectrochemical sensor for chromium(VI) by using BiOI microspheres decorated with metallic bismuth.

Composites were prepared from BiOI and Bi/BiOI-X (where x can be 1, 2, 3, or 4) by a one-step solvothermal method and used to design a photoelectrochemical (PEC) assay for chromium(VI). The chemical composition and morphology of the materials were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The results of UV-vis DRS (Diffuse reflection spectra) and photoluminescence show the composites to have higher visible light absorption and a lower electron recombination rate compared to BiOI alone. Photogenerated electrons reduce hexavalent chromium to trivalent chromium, and the consumption of electrons cause noticeable enhances of the photocurrent density after the addition of Cr(VI). Thus, the Cr(VI) concentration can be measured by monitoring the increase of photocurrent density. The Bi/BiOI-3 material displays the best performance for detecting Cr(VI). The method has a wide linear range (1 to 230 µM) and a low detection limit of 0.3 µM (at S/N = 3). It is stable, selective, reproducible and was applied to the determination of nitrite in spiked tap water and lake water samples. Graphical abstract Schematic presentation of a electrochemical sensor based on Bi/BiOI for the determination of Cr(VI).

Integrated Polypyrrole@Sulfur@Graphene Aerogel 3D Architecture via Advanced Vapor Polymerization for High-Performance Lithium-Sulfur Batteries.

Although lithium-sulfur batteries have been regarded as the most promising candidates for next-generation energy storage devices with high specific capacity, their rapid capacity decay, mainly caused by volume expansion and dissolution of polysulfides, has limited their practical applications. Aiming at these issues, herein, we have designed an ideal three-dimensional (3D)-structured polypyrrole@sulfur@graphene aerogel (PPy@S@GA) as an efficient sulfur host via advanced pyrrole vapor polymerization. GA with an interconnected 3D porous structure provides an excellent conductive network for electrons and a channel for ion transfer, as well as a physical barrier or absorber for the polysulfides. In addition, physical confinement and chemical adsorption are further strengthened by the PPy coating layer with polar nitrogen. The electrode with the PPy@S@GA 3D structure delivered a superior initial discharge specific capacity of 1135 mA h g-1 and a capacity of 741 mA h g-1 after 500 cycles at a rate of 0.5 C, with capacity fading as low as 0.031% per cycle, superior to both a sulfur electrode and a S@GA electrode. These results demonstrate that GA as a sulfur host further coated with PPy is a promising cathode for pursuing high-performance Li-S batteries.

Ni3N/NF as Bifunctional Catalysts for Both Hydrogen Generation and Urea Decomposition.

Oxygen evolution reaction (OER) has a high overpotential, which can significantly reduce the energy efficiency in water decomposition. Using urea oxidation reaction (UOR) to replace OER has been a feasible and energy-saving approach because of its lower electrode potential. Furthermore, UOR is also an important process in wastewater treatment. This paper successfully synthesizes a high-performance bifunctional catalyst for urea electrolysis. The catalyst is nickel nitride bead-like nanospheres array supported on Ni foam (Ni3N/NF). Several characterization methods are used to analyze the catalyst's morphology, structure, and composition as well as catalytic activity/stability, including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and electrochemical methods (cyclic voltammetry, linear sweep voltammetry, electrochemical impedance spectroscopy, and CAM). A concurrent two-electrode electrolyzer (Ni3N/NF∥Ni3N/NF) is constructed and used to validate the catalyst performance, and the results show that the cell achieves 100 mA·cm-2 at 1.42 V, while the cell voltage of Pt/C∥IrO2 is 1.60 V, indicating that the Ni3N/NF catalyst is superior to precious metals.