Facile Method Research Articles

Mechanochemical synthesis of nitrogen-modified microscale zero-valent iron for efficient Cr(VI) removal: The role of lattice strain

Lattice engineering of Fe0 based on heteroatom doping holds great promise in water purification owing to their tunable geometric and electronic structure. However, there is limited understanding of how nitrogen atom in Fe0 lattice structure affects its local microenvironment and corresponding reactivity toward target contaminants. Herein, microscale zero-valent iron with interstitial N doping (N-mZVI) was successfully prepared by a facile mechanochemical method for heavy metal pollution control. N-mZVI exhibited excellent reactivity for Cr(VI) elimination, and both removal efficiency and conversion rate could reach 100 %, which was 8.06 and 2.73 times higher than that of pristine ball milled mZVI, respectively. Besides, the rate constant of various heavy metals sequestration (Cr(VI), Ni(II), Pb(II), Cu(II), and Cd(II)) over N-mZVI was 61.3 ∼ 115.6-fold faster than that of pristine ball milled mZVI. N-mZVI was also demonstrated to be pH-universal, long-term stability, and environmental applicability. Experimental results and theoretical calculations indicated that tensile strain induced by interstitial N doping expanded Fe0 lattice and weakened the lattice Fe-Fe interaction, thus significantly accelerating electron transport dynamics in Fe0 core. Meanwhile, iron nitride species on the surface of N-mZVI promoted electron transfer from iron shell layer to heavy metals. This work comprehensively investigates the structure–property relationships of lattice engineering-based N-mZVI, and provides a new insight into rational design of modified mZVI with high reactivity.

Investigating the synergistic effect of RuO2 nanoparticle-decorated V2O5 nanoflakes for sensitive detection of 2,4-dinitrophenol and 2,4-dinitrotoluene

The dinitroaromatic compounds 2,4-Dinitrophenol (2,4-DNP) and 2,4-Dinitrotoluene (2,4-DNT) are prevalent contaminants in various water sources due to their extensive use in explosive synthesis and other industrial applications. The highly toxic and carcinogenic nature of these compounds poses significant risks to human health and environment, making the development of facile, rapid, cost-effective, and selective detection methods crucial. This research presents the one-step hydrothermal synthesis of RuO2 nanoparticle-decorated V2O5 nanoflakes to fabricate an electrochemical sensor for the detection of 2,4-DNP and 2,4-DNT. The synthesized materials were characterized using XRD, Raman spectroscopy, FESEM, HRTEM, and XPS techniques. The electrochemical behavior of 2,4-DNP and 2,4-DNT was investigated using cyclic voltammetry, square wave voltammetry and chronoamperometry. Under optimized conditions, 2,4-DNP and 2,4-DNT exhibited two reduction peaks corresponding to the nitro-functional groups on the aromatic ring. Notably, the 7 wt% RuO2 in V2O5 nanocomposite-modified glassy carbon electrode (RV7/GCE) demonstrated the lowest detection limits of 1.07 nM and 1.01 nM within the linear dynamic range (LDR) of 5.0 nM to 35.0 µM for 2,4-DNP, and 2,4-DNT, respectively. Furthermore, the sensor exhibited excellent reusability and reproducibility, delivering consistent results for both laboratory-controlled and real-world samples. This advancement offers efficient detection and monitoring of these hazardous compounds in environmental and industrial settings.

NiOx Passivation in Perovskite Solar Cells: From Surface Reactivity to Device Performance.

Nonstoichiometric nickel oxide (NiOx) is one of the very few metal oxides successfully used as hole extraction layer in p-i-n type perovskite solar cells (PSCs). Its favorable optoelectronic properties and facile large-scale preparation methods are potentially relevant for future commercialization of PSCs, though currently low operational stability of PSCs is reported when a NiOx hole extraction layer is used in direct contact with the perovskite absorber. Poorly understood degradation reactions at this interface are seen as cause for the inferior stability, and a variety of interface passivation approaches have been shown to be effective in improving the overall solar cell performance. To gain a better understanding of the processes happening at this interface, we systematically passivated specific defects on NiOx with three different categories of organic/inorganic compounds. The effects on NiOx and the perovskite (MAPbI3) deposited on top were investigated using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Here, we find that the perovskite's structural stability and film formation can be significantly affected by the passivation treatment of the NiOx surface. In combination with density functional theory (DFT) calculations, a likely origin of NiOx-perovskite degradation interactions is proposed. The surface passivated NiOx layers were incorporated into MAPbI3-based PSCs, and the influence on device performance and operational stability was investigated by current-voltage (J-V) characterization, impedance spectroscopy (IS), and open circuit voltage decay (OCVD) measurements. Interestingly, we find that a superior structural stability due to interface passivation must not relate to high operational stability. The discrepancy comes from the formation of excess ions at the interface, which negatively impacts all solar cell parameters.

Development of MnWO4:Ag Nanodilute Magnetic Semiconductors with Tunable Magnetic and Optoelectronic Properties

The bandgap engineered MnWO4 nanoparticles doped with Ag were developed using a facile one-pot synthesis method. The impurity doping concentration of Ag was varied from 1 to 5 weight percentages to tune the interactions between manganese tungstate and silver ions to obtain desirable magnetic and optoelectronic properties. The structural properties of the MnWO4 particles with various concentrations of Ag were investigated using X-ray diffraction. The optical properties of the pristine and Ag-doped MnWO4 particles were determined using UV‒Vis and photoluminescence spectroscopy. The impurity concentration-dependent structural transformations and changes in the vibrational modes, lattice dynamics, electronic transitions and optoelectronic properties of the prepared materials were analyzed using Raman spectroscopy. The topology, morphology and elemental analysis of the synthesized nanoparticles were elucidated using TEM, SEM, SEM and EDX techniques. The magnetic properties of the MnWO4:Ag nanoparticles were measured using a vibrating sample magnetometer (VSM). The obtained results suggested that Ag-doped MnWO4 nanosystems show enhanced and tunable magnetic properties suitable for nanodilute magnetic semiconductor (nDMS) applications. The presented work opens a range of possibilities for the development of advanced materials with applications in optoelctronics, nanomedicine, energy-efficient electronic devices and energy conversion.

MoSe2 nanosheets-based sensor for electrochemical detection of dopamine, ascorbic acid, and uric acid

There has been a growing interest in the field of transition metal dichalcogenide (TMD) materials and their potential applications in the field of electrochemical sensors. In the present work, molybdenum diselenide (MoSe2), as a typical representative of TMD, was prepared using a facile hydrothermal method and characterized in terms of its morphological and structural properties. Then, the obtained MoSe2 was dispersed in various solvents to investigate its electrocatalytic properties towards dopamine (DA), ascorbic acid (AA), and uric acid (UA). The electrochemical measurements revealed that deionized water is an effective solvent to disperse the MoSe2 and modify electrodes with the MoSe2 for electrochemical applications. Furthermore, the glassy carbon electrode (GCE) modified with the MoSe2, referred as GCE-MoSe2, was used as an electrochemical sensor to simultaneously detect the DA, AA, and UA. The GCE-MoSe2 exhibited wide linear detection with concentration ranges of 1–333 µM for DA, 50–3440 µM for AA, and 5–1146 µM for UA in phosphate buffer solution and low detection limits (LODs) of 0.57 µM, 13.7 µM, and 1.75 µM, respectively. The electrode further displayed good selectivity, reproducibility, and stability. This work provides valuable insights on constructing electrochemical sensing devices with high analytical performance using the important two-dimensional (2D) TMD materials.

Photocarrier relay modulating solar CO2-to-Syngas conversion

Solar-driven syngas generation by CO2 reduction provides a sustainable strategy to produce renewable fossil fuels. Nevertheless, this promising approach often suffers from tough CO2 activation, sluggish reaction kinetics and complex selectivity. Herein, we exquisitely constructed spatially directional charge transport channel over two-dimensional transition metal chalcogenide (TMC)-based heterostructure via a facile and universal electrostatic self-assembly method. Tailor-made positively charged non-conjugated insulating polymer of poly(diallyl-dimethyl-ammonium chloride) (PDDA) and negatively charged graphene oxide (GO) precursor as building blocks are controllably anchored on the TMC substrate, by which ultrathin PDDA layer is intercalated at the interface of GO and TMC. We ascertain that, in this customized sandwiched heterostructures, PDDA interim layer functions as an electron-relaying mediator, whilst graphene (GR) obtained from in-situ GO reduction during the photocatalytic reaction serves as a terminal electron-trapping reservoir, synergistically facilitating the spatially vectorial charge separation/migration over TMC, thus endowing the TMC/PDDA/GR heterostructures with conspicuously enhanced visible-light-driven photoactivity toward CO2-to-syngas conversion. Our work would inspire judicious ideas for finely modulating charge transfer over polymer-mediated photosystems and benefit our fundamental understanding of solar CO2 conversion.

Ultrahigh energy harvesting ability of PVDF incorporated with 2D halide perovskite nanosheets via interface effect

Two-dimensional (2D) perovskites have recently emerged as an new family of ferroelectrics and attracted extensive attention for their specific surface interface characteristics benefitting from the unique structure by inserting hydrophobic organic cations into conventional three-dimensional frameworks. In this study, 2D metal–organic perovskite nanosheets, (C4H9NH3)2CsPb2Br7, ((BA)2CsPb2Br7), were successfully synthesized by facile temperature-cooling method and introduced into poly (vinylidene fluoride) (PVDF) polymer fibers to construct flexible piezoelectric energy harvester (PEH). (BA)2CsPb2Br7/PVDF nanofibers reveal a high piezoelectric coefficient (d33) of 63.3 pm/V, which is 2.9 times of the PVDF polymer (21.7 pm/V). Principally, the PVDF composite with 5 wt% (BA)2CsPb2Br7 nanosheet filler assumes an superior electroactive phase amount of about ∼ 93 % profiting from the interfacial interaction between BA+ cations of (BA)2CsPb2Br7 and the dipoles of PVDF. The PEH based on (BA)2CsPb2Br7 nanosheets embedded in PVDF fibers showed a maximum output voltage, 135 V, which is almost 17 times of the PEH based on neat PVDF fibers. Furthermore, the interfacial interaction between (BA)2CsPb2Br7 and PVDF was analyzed by first principle DFT study which reveals electrons migrate and the interfacial polarization between the interface. Simultaneously, (BA)2CsPb2Br7/PVDF composite fibers based PEH reveals exceptional long-term stabilities and durability. More attractively, the exceptional performance of this fabricated PEH evinces a pressure sensitivity of ∼ 7.3 V/N and bio-mechanical harvesting behavior arising from varied human motions, such as beating, pressing, twisting, walking and running. This cost-effective and high performance of (BA)2CsPb2Br7/PVDF based PEH is favorable for the continuation of 2D halide perovskites for further application in new energy and biomechanical filed.

Room-Temperature Synthesis of Covalently Bridged MOP@TpPa-CH3 Composite Photocatalysts for Artificial Photosynthesis.

The conversion of CO2 into useful chemicals via photocatalysts is a promising strategy for resolving the environmental problems caused by the addition of CO2. Herein, a series of composite photocatalysts MOP@TpPa-CH3 based on MOP-NH2 and TpPa-CH3 through covalent bridging have been prepared via a facile room-temperature evaporation method and employed for photocatalytic CO2 reduction. The photocatalytic performances of MOP@TpPa-CH3 are greater than those of TpPa-CH3 and MOP-NH2, where the CO generation rate of MOP@TpPa-CH3 under 10% CO2 still reaches 119.25 μmol g-1 h-1, which is 2.18 times higher than that under pure CO2 (54.74 μmol g-1 h-1). To investigate the structural factors affecting the photocatalytic activity, MOP@TBPa-CH3 without C═O groups is synthesized, and the photoreduction performance is also evaluated. The controlling experimental results demonstrate that the excellent photoreduction CO2 performance of MOP@TpPa-CH3 in a 10% CO2 atmosphere is due to the presence of C═O groups in TpPa-CH3. This work offers a new design and construction strategy for novel MOP@COF composites.

Comparative study of laser-induced graphene fabricated in atmospheric and interface-confined environments

Laser-induced graphene (LIG) has found widespread applications in various carbon-based electronics, such as sensors, optoelectronics, and energy storage devices, due to its low cost, high efficiency, and large-scale fabrication potential. Here, two laser-induced carbonization techniques are investigated in terms of structural integrity (uniformity and densification) and electrical property by a combined experimental and theoretical approach; these techniques, namely interface and surface ablation, operate in confined and ambient environments, respectively. The property of LIG for each laser-induced carbonization technique is systematically studied using optical and electrical characterization methods. The results show that the naturally confined and oxygen-free environment of interface ablation can fabricate more compact and intact LIG than surface ablation in an open and oxygen environment, thus enabling a 7.6 times reduction of the square/sheet resistance. The underlying mechanism for these improved properties is the compressive thermal stress and higher carbonization efficiency of interface ablation. The better structural integrity and electrical property of interface-ablated graphene enable a four-fold improvement in the specific areal capacitance of supercapacitors. These findings present that interface ablation is a more effective and facile method to enable the scalable preparation of intact and highly conductive LIG for its potential use in high-performance carbon-based electronics.

Synthesis and synergistic antibacterial efficiency of chitosan-copper oxide nanocomposites

Copper and chitosan are used for biomedical applications due to their antimicrobial properties. In this study, a facile method for the synthesis of chitosan-copper oxide nanocomposites (nCuO-CSs) was modified, yielding stable colloidal nCuO-CSs suspensions. Using this method, nCuO-CSs with different copper-to-chitosan (50–190 kDa) weight ratios (1:0.3, 1:1, 1:3) were synthesized, their physicochemical properties characterized, and antibacterial efficacy assessed against Gram-negative Escherichia coli and Pseudomonas aeruginosa, and Gram-positive Staphylococcus aureus. The nCuO-CSs with a primary size of ∼10 nm and a ζ-potential of >+40 mV proved efficient antibacterials, acting at concentrations around 1 mg Cu/L. Notably, against Gram-negative bacteria, this inhibitory effect was already evident after a 1-h exposure and surpassed that of copper ions, implying to a synergistic effect of chitosan and nano-CuO. Indeed, using flow cytometry and confocal laser scanning microscopy, we showed that chitosan promoted interaction between the nCuO-CSs and bacterial cells, facilitating the shedding of copper ions in the close vicinity of the cell surface. The synergy between copper and chitosan makes these nanomaterials promising for biomedical applications (e.g., wound dressings).

Acid-base neutralization strategy for immobilization amino acid ionic liquid within sulfonic acid-based COF as a switch for selective conversion of epoxides

Covalent organic frameworks (COFs) and ionic liquids (ILs) as raw materials exhibit effective catalytic performance and adsorption capabilities in the reaction of epoxides and atmospheric CO2, respectively. Nonetheless, bonding modes between ILs and COFs have restricted their utility, thereby constraining the in-depth study of synergistic catalytic mechanisms over these composite catalysts. Herein, a heterogeneous composite ([DBUH]2Cys@COF-X) were successfully prepared by the facile acid-base neutralization method, incorporating varying amounts of amino acid ILs ([DBUH]2Cys) into the pore channels of sulfonic acid-based COF (TpPa-SO3H). [DBUH]2Cys@COF-3 efficiently catalyzed epichlorohydrin with a yield of 96.38 % without any solvent or co-catalyst under atmospheric CO2. Notably, larger sterically hindered epoxides were selectively blocked on the surface of [DBUH]2Cys@COF-3, enabling [DBUH]2Cys@COF-3 to act as a gatekeeper for selectively catalyzing small sterically hindered epoxides due to [DBUH]2Cys was distributed within the pore channels of [DBUH]2Cys@COF-3. Through DFT calculations, comprehensive understanding of the synergistic activation conferred of -COO- and [DBUH]+ towards CO2 and epoxides in [DBUH]2Cys@COF-3 and the ring-opening mechanism was clarified. This work presents a fresh outlook on the catalyst design by the facile acid-base neutralization method for efficiently catalyzing small-hindered epoxides under atmospheric CO2.

Amorphous-Crystalline Heterostructured Nanoporous High-Entropy Alloys for High-Efficiency pH-Universal Water Splitting.

Developing high-efficiency durable electrocatalysts in wide pH range for water splitting is significant for environmentally-friendly synthesis of renewable hydrogen energy. Herein, a facile method by dealloying designable multicomponent metallic glass precursors is reported to synthesize amorphous-crystalline heterostructured nanoporous high-entropy alloys (AC-HEAs) of CuAgAuPtPd, CuAgAuIrRu, and CuAgAuPtPdIrRu, heaped up by nanocrystalline particles with an average size of 2-3nm and the amorphous glued phase. The synthesized AC-HEA-CuAgAuPtPd owns highly catalytic performances for hydrogen evolution reaction (HER), with 9.5 and 20mV to reach 10 mA·cm-2 in 0.5m H2SO4 and 1.0m KOH, and AC-HEA-CuAgAuIrRu delivers 208 and 200mV for oxygen evolution reaction (OER). Moreover, a two-electrode electrolyzer made of the AC-HEA-CuAgAuIrRu bifunctional electrodes exhibit a low cell voltage of 1.48 and 1.49V in the acidic and alkaline conditions at 10 mA·cm-2 for overall water splitting. Combining the enhanced catalytic activities from nanoscale amorphous structure and atom-level synergistic catalyst in AC-HEAs provides an effective pathway forpH-universal electrocatalysts of water splitting.

Tuning the composition of manganese cobaltite spinel with tungsten for enhanced energy storage performance

The development of efficient and innovative energy storage devices is a necessity of the hour. Emerging nanomaterials possessing tungsten are believed to have unique physicochemical properties and their application could be extended over a wide spectrum as nanocomposite electrodes for effective high voltage energy storage applications. In the present work, a one-step hydrothermal process has been employed to prepare Tungsten (W) doped spinel oxide MnWxCo2–2xO4 (MWCO) nanostructures, where x varies from 0.01 to 0.05. The spectroscopic characterization studies proved spherical subunits embedded onto nanosheets formed by W doped bimetallic oxide with a crystalline phase. On employing the synthesized material in asymmetric supercapacitor application, it was inferred that W doping had a notable effect on the electrochemical performance. The optimized doping ratio (x=0.03) revealed an appreciable specific capacitance of 91 F g−1 at the current of 0.5 A g−1, with a retention in the capacitance of more than 80 % even after 10000 GCD cycles. Remarkable specific energy (3.17 Wh kg−1) and specific power (98 W kg−1) were also noted. Hence, the material synthesized in this study by our facile method is thought to be highly suitable as an electrode for high-performance energy storage applications.

Synthesis Ag-Hollandite by mild route for highly efficient ozone decomposition

Catalytic ozone (O3) decomposition is a promising technology for curbing indoor O3 pollution, whereas its application is limited by the stability and moisture resistance of heterogeneous catalysts. Ag-Hollandite is a capable solution, but its facile synthesis still lacks systematic investigation. In this study, Ag-Hollandite catalysts were prepared using AgMnO4 as the precursor by reflux (AMO-Re), hydrothermal (AMO-HT), and homogeneous (AMO-HR) methods, respectively. The as-prepared samples showed excellent stability under moisture conditions, with the optimal one maintaining an O3 conversion rate of 99.19 % after 100 h. In the characterization results, Ramsdellite (R-MnO2) was identified as an intermediate species in the synthesis. AMO-HR exhibits higher activity due to enhanced active site exposure and weakened adsorption towards *OO species, while reduced surface hydroxyl content was a crucial factor for moisture resistance. This study aims to contribute insights for preparing catalysts by a facile method.

The interaction of light with oxygen-vacancy-rich W18O49 nanoparticles synthesized using different acid molarities for acidic and neutral water treatments

Toxic industrial compounds as a global difficulty can adversely impact people's health and the environment which motivates studies on the interaction of light and metal oxide nanoparticles to treat the water through adsorption or photocatalysis mechanism by nanoparticles. In the paper, oxygen-vacancy-rich W18O49 nanorods are successfully synthesized by a facile one-pot hydrothermal method using different molarities of hydrochloric acid (HCl) (2–12 M) as proposed candidates to treat the wastewater and solve the global difficulty related to treating the acidic water. The results declare that the change in acid molarity leads to noteworthy changes in the characteristic properties of the produced W18O49 nanorods, and the lowest acid molarity (2 M) causes the formation of uniform and pure monoclinic W18O49 nanorods with the high specific surface area (SSA) of 51.33 m2/g. Furthermore, the nanorods exhibit indirect and direct band gap energies in the range of 2.52–2.68 eV and 2.54–3.08 eV, respectively, as influenced by varying acid molarities (2–12 M). Furthermore, the impressive effects of acid molarity on the methylene blue removal efficiency of the nanorods under ultraviolet (UV) light are observed. The highest efficiency is obtained for W18O49 nanorods synthesized using the acid molarity of 2 M which can be explained by its high SSA, small band gap energy, generation of a large number of electron-hole pairs, and its efficient charge separation. The efficiencies of water treatment reach up to 99 % and 99.5 % at pH of 7 and 5, respectively, which is an excellent achievement and leads to proposing the mentioned W18O49 nanorods as an excellent candidate for treating wastewater and acid factory effluent which represents an appreciable breakthrough in addressing the issue.

Optimization of degradation of potassium ethyl xanthate using Fe2O3/TiO2/Flyash nanophotocatalyst using Taguchi statistical approach

Xanthate from mineral processing wastewater is a major threat to the ecosystem. Photocatalysis is emerging as the most effective process with the invention of new nanophotocatalytic materials. The present research focuses on developing the ternary nanocomposite Fe2O3/TiO2/Flyash by a facile hydrothermal method combined with a water bath precipitation method for the efficient degradation of potassium ethyl xanthate (KEX). Taguchi’s experimentation (L16) orthogonal array is used for the optimization of process parameters to get maximum KEX degradation efficiency. The optimized parameters are found to be calcination temperature 400 OC, photocatalyst dosage 0.7 g/L, pH 5, pollutant concentration 10 mg/L, and light intensity 100 W. The percentage contribution of each parameter is obtained through the ANOVA statistical approach as calcination temperature > pH>pollutant concentration > photocatalyst dosage > light intensity. The adsorption mechanism follows the Freundlich isotherm and fits well with pseudo-first-order and second-order kinetics. Material characterization is also done to analyze the crystal structure and morphology of the newly developed nanocomposite to gain a better understanding of the mechanism. This study indicates that the newly developed nanocomposite photocatalyst can effectively degrade potassium ethyl xanthate under light irradiation for 60 min.

Stable aluminum-lithium alloy fuels for solid propellants by facile surface modifying

As a highly reactive metal fuel, aluminum–lithium (Al-Li) alloy is an ideal candidate for replacing Al powders in solid propellants. However, the Li solid solution and AlLi compounds on the surface of Al-Li alloy powders display high reactivity, which can react with a large number of organic and inorganic reagents. Thus, the incompatibility of Al-Li alloy with other components of propellants makes it difficult to be further applied in propellants. In this study, surface-modified Al-Li alloy powders (Li content of 5 wt%) with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS17) were prepared by a facile self-assembly method, which made the alloy powders super-hydrophobic. The results of SEM, XPS and FIB-TEM show that the surface of Al-Li alloy powder is well-coated by an evenly distributed FAS17 layer. Due to the fluoroalkyl on the surface of the powders, the water contact angle increased by 91°and the intensity of the reaction between alloy powders and water is significantly reduced, which results in improved compatibility with other components of propellants.Meanwhile, the propellant grain of surface-modified powders had fewer defects than the sample before coating, and showed original excellent combustion performance. The average combustion pressure and pressurization rate increased by ∼114 kPa and ∼8613 kPa/s, and the steady burning rate increased by 0.24 mm/s. Therefore, the surface-modified Al-Li alloy powders with FAS17 are expected to be an attractive candidate as a highly active and stable fuel in solid propellants.

Chemically bonded CdBiO2Br/BiOI heterojunction with strong interfacial electric field for enhanced photocatalysis

Semiconductor-based photocatalysis shows a large potential for contaminant purification, however, a single semiconductor photocatalyst suffers from low utilization efficiency of photogenerated carriers, leading to inferior photocatalytic activity. Herein, CdBiO2Br@BiOI (CBOB@BiOI) heterojunction with a close interface interaction is prepared by a facile precipitation method at the ambient atmosphere. X-ray photoelectron spectroscopy and Density Functional Theory calculations on work function consistently disclose that the formation of CdBiI bonds at the interface induces the electron migration from BiOI to CdBiO2Br, which allows CBOB@BiOI heterojunction to have a strong interfacial electric field (IEF) for efficiently separating photocharges. In-situ Kelvin-probe Force Microscopy measurement demonstrates that CBOB@BiOI heterojunction shows a larger surface potential than CdBiO2Br and BiOI in dark and a potential decrease under illumination, which can be ascribed to the photoinduced electron migration within heterojunction driven by the IEF. Thus, the CBOB@BiOI heterojunction shows a much more efficient photocatalytic activity for the breakdown of tetracycline hydrochloride (TC), which is 2.44 and 3.99 times higher than CdBiO2Br and BiOI, respectively. Electron Paramagnetic Resonance test also confirms that the CBOB@BiOI heterojunction produces much more superoxide radicals and holes as reactive species than CdBiO2Br and BiOI. Furthermore, the latent degradation pathways of TC are investigated by Liquid Chromatograph Mass Spectrometer. This work may provide new ideas for constructing intimately bonded heterojunction photocatalysts with a strong IEF for efficient photocatalytic activity.

The Facile and Controllable Synthesis of Ultrafine Sn Nanocrystals Loaded on Carbon Black for High-Performance Lithium Storage.

Sn and C nanocomposites are ideal anode materials for high-energy and high-power density lithium ion batteries. However, their facile and controllable synthesis for practical applications is still a critical challenge. In this work, a facile one-step method is developed to controllably synthesize ultrafine Sn nanocrystals (< 5 nm) loaded on carbon black (Sn@C) through Na reducing SnCl4 by mechanical milling. Different from traditional up-down mechanical milling method, this method utilizes mechanical milling to trigger bottom-up reduction reaction of SnCl4. The in-situ formed Sn nanocrystals directly grow on carbon black, which results in the homogeneous composite and the size control of Sn nanocrystals. The obtained Sn@C electrode is revealed to possesses large lithium diffusion coefficient, low lithiation energy barrier and stable electrochemical property during cycle, thus showing excellent lithium storage performance with a high reversible capacity (942 mAh g-1 at a current density of 100 mA g-1), distinguished rate ability (480 mAh g-1 at 8000 mA g-1) and superb cycling performance (730 mAh g-1 at 1000 mA g-1 even after 1000 cycles).

A facile acid-etching defect-rich leaf-like zeolitic-imidazolate framework adsorbent for simultaneous removal of organic/inorganic phosphorus pollutants from wastewater

Organophosphorus herbicide glyphosate and inorganic phosphate usually coexist in wastewater, leading to water eutrophication and posing risks to human health. In this study, acid-etching defect-rich leaf-like zeolitic-imidazolate framework (ae-ZIF-L) adsorbent was developed by a facile etching method to investigate its simultaneous removal performance of glyphosate and phosphate. Compared to ZIF-L precursor, ae-ZIF-L displayed a maximum adsorption capacity for phosphate and glyphosate of 164.4 mg g–1 and 12.7 mg g–1, respectively. The overall enhanced adsorption performance of ae-ZIF-L was primarily attributed to abundant Zn defects, resulting in higher positive zeta potentials to enhance electrostatic attraction. Notably, in the phosphate/glyphosate coexistence system, ae-ZIF-L has extremely high removal rates of 99.1 % and 90.9 %, while ZIF-L has removal rates of 97.7 % and 39.4 %, respectively. Furthermore, after four adsorption-desorption cycles, the removal rates of phosphate/glyphosate by ae-ZIF-L remained at 84.8 % and 82.5 %, respectively. In conclusion, ae-ZIF-L proved to be an efficient and reusable adsorbent with promising application for the treatment of organic/inorganic phosphorus pollution in wastewater.