Flower-like Architectures Research Articles

Effective stress dissipation by multi-dimensional architecture engineering for ultrafast and ultralong sodium storage

Stress accumulation is a key factor leading to sodium storage performance deterioration for NiSe2-based anodes. Therefore, inhibiting the concentrated local stress during the sodiataion/desodiation process is crucial for acquiring stable NiSe2-based materials for sodium-ion batteries (SIBs). Herein, a stress dissipation strategy driven by architecture engineering is proposed, which can achieve ultrafast and ultralong sodium storage properties. Different from the conventional sphere-like or rod-like architecture, the three-dimensional (3D) flower-like NiSe2@C composite is delicately designed and assembled with one-dimensional nanorods and carbon framework. More importantly, the fundamental mechanism of improved structure stability is unveiled by simulations and experimental results simultaneously. It demonstrates that this designed multidimensional flower-like architecture with dispersed nanorods can balance the structural mismatch, avoid concentrated local strain, and relax the internal stress, mainly induced by the unavoidable volume variation during the repeated conversion processes. Moreover, it can provide more Na+-storage sites and multi-directional migration pathways, leading to a fast Na+-migration channel with boosted reaction kinetic. As expected, it delivers superior rate performance (441 mA h g−1 at 5.0 A g−1) and long cycling stability (563 mA h g−1 at 1.0 A g−1 over 1000 cycles) for SIBs. This work provides useful insights for designing high-performance conversion-based anode materials for SIBs.

Synergistic engineering of heteroatomic N-doping and PPy modification in flower-like vanadium sulfide anode enables stable sodium storage

Vanadium sulfide, an appealing anode candidate for sodium ion batteries (SIBs), still encounters considerable volume fluctuation and sluggish Na+ diffusion kinetics, which inevitably gives rise to unsatisfactory rate capability and severe capacity decay. Herein, we successfully designed and constructed an outstanding sodium-storage feature and exceedingly stable anode for SIBs in the form of three-dimensional flower-like architecture composing of phosphorus doped VS2 wrapped by conductive elastic polypyrrole (PPy) layer (i.e., P-VS2@PPy). Through leveraging the multifunctional synergistic effect of composition and structure, involving enhanced electronic conductivity, reduced volumetric fluctuation, accelerated charge/ion transfer efficiency, and remarkable surface-capacitive behaviors can guarantee significantly enhanced electrochemical sodium-storage ability of P-VS2@PPy composites. As a consequence,such P-VS2@PPy is endowed with desirable rate characteristic accompanied with long-period cyclic lifespan (436.7 mAh/g at 20.0 A/g after 2600 cycles), which far outperform contrastive P-VS2 and pure VS2 samples. Meticulous kinetic analysis combined with theoretical simulations conclude that phosphorus doping and PPy coating have substantial effects on strengthening ionic and electron diffusion kinetics. Thorough examination and analysis of the insertion and conversion mechanisms of P-VS2@PPy was conducted through ex situ tests, revealing superior reversible phase transformation between original VS2, intermediate NaVS2, and final Na2S/V. Additionally, a practical application test demonstrates that sodium ion full-cell and hybrid capacitor based on P-VS2@PPy anode showcase significant capacity contribution and outstanding specific energy output, capable of effortlessly lighting up a LED screen.

Mechanochemically synthesized flower-like bismuth oxyhalides: An electrochemical platform for diclofenac detection

The emerging drug diclofenac (DICF) has been found to penetrates aquatic systems at alarming concentrations and poses serious and irreversible ecotoxicological threats around the world. In this work, we present the solid-state mechanochemical synthesis of 3D flower-like bismuth oxyhalides (BiOX, where X = Cl, Br, and I) as electrode materials for electrochemical detection of DICF. The characteristics of the flower-like BiOX are systematically investigated using spectroscopic and microscopic techniques. The BiOI-modified glassy carbon electrode (GCE) exhibits superior electrochemical performance for DICF detection compared to the pristine GCE, BiOCl/GCE, and BiOBr/GCE. The 3D flower-like architecture of BiOI facilitates favorable electrocatalytic activities due to its abundant electroactive sites, good conductivity, large surface area, and fast ion diffusion. Notably, the BiOI/GCE displays wide linear ranges (0.5–11.3 & 11.3−76), a low limit of detection (0.11 μM), high sensitivity (1.33 μA μM–1 cm–2), excellent repeatability (2.91 %), good reproducibility (2.88 %), and anti-interfering ability (<±5 %). To validate the practicality of the fabricated BiOI/GCE, the quantitative detection of DICF in human urine and river water is demonstrated and achieves acceptable recovery values. This study introduces an innovative approach to design and produce electrode materials with distinct properties, enabling enhanced electrocatalysis for various electrochemical sensing applications.

Synthesis of Pd-Doped SnO2 and Flower-like Hierarchical Structures for Efficient and Rapid Detection of Ethanolamine.

In this study, we successfully synthesized a Pd-doped SnO2 (Pd-SnO2) material with a flower-like hierarchical structure using the solvothermal method. The material's structural proper-ties were characterized employing techniques such as XRD, XPS, FESEM and HRTEM. A gas sensor fabricated from the 2.0 mol% Pd-SnO2 material demonstrated exceptional sensitivity (Ra/Rg = 106) to 100 ppm ethanolamine at an operating temperature of 150 °C, with rapid response/recovery times of 10 s and 12 s, respectively, along with excellent linearity, selectivity, and stability, and a detection limit down to 1 ppm. The superior gas-sensing performance is attributed to the distinctive flower-like hierarchical architecture of the Pd-SnO2 and the lattice distortions introduced by Pd doping, which substantially boost the material's sensing characteristics. Further analysis using density functional theory (DFT) has revealed that within the Pd-SnO2 system, Sn exhibits strong affinities for O and N, leading to high adsorption energies for ethanolamine, thus enhancing the system's selectivity and sensitivity to ethanolamine gas. This research introduces a novel approach for the efficient and rapid detection of ethanolamine gas.

Dual Strategy of Morphology Optimization and Interlayer Expansion in VS2 Cathode Toward High-Performance Mg-Li Hybrid Ion Batteries.

Combining the merits of the dendrite-free formation of a Mg anode and the fast kinetics of Li ions, the Mg-Li hybrid ion batteries (MLIBs) are considered an ideal energy storage system. However, the lack of advanced cathode materials limits their further practical application. Herein, we report a dual strategy of morphology optimization and interlayer expansion for the construction of hierarchical flower-like VS2 architecture coated by N-doped amorphous carbon layers. This tailored hierarchical flower-like structure coupled with homogeneous N-doped amorphous carbon layers cooperatively provide more active sites and buffer volume changes, thus realizing the enhancement of capacity and structural stability. Moreover, the enlarged interlayer spacing caused by the cointercalation of polyvinylpyrrolidone and ammonium ions can effectively promote the charge transfer rate and facilitate the rapid ion diffusion, as further demonstrated by electrochemical results and theoretical calculations. These features endow the hierarchical flower-like VS2 cathode with superior specific energy density (644.4 Wh kg-1, average voltage of 1.2 V vs Mg2+/Mg) and excellent rate capability (181.1 mAh g-1 at 2000 mA g-1). Systematic ex situ characterization measurements are employed to reveal the ion storage mechanism, which confirms that Li+ storage plays a leading role in the capacity contribution of MLIBs. Our strategy is in favor of providing useful insights to design and construct MLIBs with high energy density and excellent rate performance.

Exploring Mo-ZnO@NF for hydrogen generation and methylene blue remediation: sunlight-driven catalysis

In this study, we elucidate the synthesis and characterization of molybdenum (Mo) doped zinc oxide (ZnO) nanoflowers (Mo-ZnO@NF) fabricated via a hydrothermal approach, showcasing their potential application in hydrogen generation and dye degradation. The successful synthesis of these nanoflowers is achieved through the deliberate incorporation of Mo ions into the ZnO lattice, yielding a distinctive hierarchical flower-like morphology. Comprehensive structural, morphological, and optical analyses are conducted employing a suite of analytical techniques, encompassing XRD, Raman, FESEM, and UV-Visible spectroscopy. XRD analysis confirms the retention of the hexagonal wurtzite crystal structure, accompanied by discernible peak shifts indicative of Mo ion integration. FESEM imaging further elucidates the flower-like architecture of Mo-ZnO, underscoring the intricate morphological features. Photocatalytic assessment reveals the remarkable efficacy of Mo-ZnO@NF, as evidenced by an unprecedented hydrogen evolution rate of 2024 mmol/h/g and 97% Methylene Blue (MB) dye degradation within a mere 40-minute timeframe. Furthermore, a comparative investigation between pristine ZnO and varying Mo doping concentrations (ranging from 1% to 5%) underscores the optimal doping concentration of 1% Mo in ZnO. This concentration threshold is shown to engender superior photocatalytic performance, potentially attributed to enhanced charge carrier separation and increased surface area conducive to catalytic reactions. Overall, this study not only advances our understanding of Mo-ZnO@NF nanostructures but also elucidates key insights into optimizing their photocatalytic efficacy for diverse environmental remediation applications.

Effective strategy for alleviation of oil contamination in marine via the superhydrophobic biochar: Performances, mechanisms and environmental recalcitrance

The performance of layered double hydroxides (LDH)-biochar composite on alleviating oil spill pollution is poorly understood. A superhydrophobic biochar (NCY) was synthesized from the pristine wood chips biochar (WCB) after the surface deposition of NiCo-LDH (NCB) and hydrophobic modification with stearate. The oil removal potential of the designed biochars was investigated via the diesel oil/crude oil adsorption experiments and the environmental recalcitrance evaluation. The compared characterization results revealed that NiCo-LDH was successfully deposited onto biochar matrix via the electrostatic attraction and pore filling effect, which facilitated a special flower-like hierarchical architecture rough surface for biochar and hinder the multi-layer stacking of LDH. Benefit from the constructed hierarchical architecture, the occupancy of oxygen-containing functional groups and hydrophobic modification of stearate, the water contact angle of NCY (156°) was remarkably larger than NCB (117°) and WCB (50.1°), which exhibit a superhydrophobic. The maximum diesel oil sorption capacities of biochars increased from 3.28 g/g in WCB to 5.64 g/g in NCB and 11.6 g/g in NCY, as well as the maximum crude oil sorption capacities of biochars showed a similar trend (WCB: 4.64 g/g, NCB: 8.74 g/g, NCY: 18.6 g/g). Accordingly, NCY showed higher oil adsorption capacity than NCB and WCB mainly due to the enhanced hydrophobic forces and the π-π electron donor-acceptor interaction resulted from lower amount of O-containing functional groups and superhydrophobic surface wettability. Furthermore, the application of LDH remarkably improved the environmental recalcitrance of biochar (resist to the chemical oxidation and thermal decomposition in marine) due to the coating of NiCo-LDH could enhance the bulk stability of biochar and increase the liable carbon content in biochar. This study proved that the application of NiCo-LDH and stearate could be an effective approach for improve the oil pollution remediation capacity and the environmental recalcitrance of biochar.

MOFs-derived 3D flower-like Y2O3/C microspheres with efficient electromagnetic wave absorption properties

Y2O3 has emerged as a promising material for electromagnetic wave (EMW) absorption due to its excellent dielectric properties. However, the inherent insulating nature and single loss mechanism limit its absorption performance. Research on the microstructure modulation and component regulation of Y2O3-based absorbers remains relatively unexplored. In this work, Y2O3/C composites with flower-like architectures were synthesized for the first time via a metal-organic framework (MOFs) templating method. The effects of pyrolysis temperature on the microstructure, phase composition, and EMW absorption performance of the Y2O3/C composites were systematically investigated. At a pyrolysis temperature of 800 °C, the flower-like Y2O3/C microsphere exhibited optimal EMW absorption performance. The minimum reflection loss (RL) of pristine Y2O3 was only −4.75 dB, while the Y2O3/C composite achieved a minimum RL of −51.77 dB and a maximum effective absorption bandwidth of 4.32 GHz. Moreover, by simply adjusting the matching thickness, the optimal sample exhibited strong absorption (RL < −30 dB) over a wide frequency range of 4–18 GHz. The incorporation of carbon effectively neutralized the insulating nature of Y2O3, thereby optimizing the impedance matching. The synergistic effects of multiple loss mechanisms, including polarization loss, resistance loss, and interfacial polarization, facilitated substantial EMW attenuation. This study provides a promising strategy for the design and fabrication of high-performance rare-earth oxide EMW absorbers with tunable morphologies and properties.

Fabrication of oxygen-vacancy-adjustable Yb3+/Er3+ co-doped BiOBr 3D flowerlike hierarchical architectures with enhanced photocatalytic activity under broad spectrum (UV/vis/NIR) excitation

A novel Yb3+/Er3+ co-doped BiOBr photocatalyst with 3D flowerlike hierarchical architectures were successfully fabricated through self-assembled process without any templates under hydrothermal conditions, and the structure and properties of the photocatalysts were characterized. The results indicate that Yb3+ ions and Er3+ ions are successfully doped into the lattice of BiOBr, and the as-obtained photocatalyst can respond the NIR light and emit red and green light due to the up-conversion effect of the rare-earth ions. Meanwhile, with co-doped Yb3+/Er3+ ions content increasing, oxygen vacancy concentration in the photocatalyst rises. The oxygen vacancy will form the intermediate energy band, which can decrease the photon energy required for electronical transition, and thus help to utilize the luminous energy generated by up-conversion luminescence. Moreover, the appropriate introduction of defects (oxygen vacancy defect and impurity atom) can further promote the transfer and separation efficiency of photo-generated carriers. Hence, Yb3+/Er3+ co-doped BiOBr photocatalyst exhibits enhanced photocatalytic properties under broad spectrum (UV/vis/NIR) excitation, which is about 4 times as high as that of pure BiOBr.

Novel superhydrophobic sponge with flower-like architecture for oily emulsion separation and organic pollutants photodegradation

Design functionalized absorbent materials that fulfillment complex requirements in sophisticated water-treatment fields remains challenging. In this paper, a novel superhydrophobic/superoleophilic sponge with flower-like channel structures and a photodegradation functionality was fabricated via in-situ chelation of zinc oxide (ZnO) and nano-Ag particles. After low surface energy modification with POTS, the as-prepared sponge displayed remarkable superwettability, with a water contact angle (WCA) of 158.8° ± 1.3°. This endowed it with the ultrafast, selective absorption of diverse oils that are 33.9–135.2 times of their own weight. The prepared sponge’s emulsified oil separation efficiency can reach 99.87%, owing to its superhydrophobic/superoleophilic properties and the electrostatic attraction demulsification, guiding effect of ZnO layer crystal plane. Furthermore, the construction of Schottky barrier at the ZnO@Ag interface reduced the recombination rate of photoexcited electrons and electron-holes. Thereby, the prepared sponge’s photodegradation efficiency reached up to 97.07% after 4 h sunlight irradiation. Notably, the stress attenuation of the prepared sponge was only 14.6% after 100 absorption cycles, indicating its excellent mechanical stability. Moreover, the prepared sponge showed excellent environmental tolerance under severe conditions with its WCA stably exceeding 150.0°. Thus, this durable superwetting sponge can be effectively used for oil/water emulsion separation and organic pollutant degradation.

Controlled solvothermal synthesis of self-assembled SrTiO3 microstructures for expeditious solar-driven photocatalysis dye effluents degradation

In this work, the self-assembled SrTiO3 (STO) microstructures were synthesized via a facile one-step solvothermal method. As the solvothermal temperature increased from 140 °C to 200 °C, the STO changed from a flower-like architecture to finally an irregularly aggregated flake-like morphology. The photocatalytic performance of as-synthesized samples was assessed through the degradation of rhodamine B (RhB) and malachite green (MG) under simulated solar irradiation. The results indicated that the photocatalytic performance of STO samples depended on their morphology, in which the hierarchical flower-like STO synthesized at 160 °C demonstrated the highest photoactivities. The photocatalytic enhancement of STO-160 was benefited from its large surface area and mesoporous configuration, hence facilitating the presence of more reactive species and accelerating the charge separation. Moreover, the real-world practicality of STO-160 photocatalysis was examined via the real printed ink wastewater-containing RhB and MG treatment. The phytotoxicity analyses demonstrated that the photocatalytically treated wastewater increased the germination of mung bean seeds, and the good reusability of synthesized STO-160 in photodegradation reaction also promoted its application in practical scenarios. This work highlights the promising potential of tailored STO microstructures for effective environmental remediation applications.

Customized self-assembled bimetallic hybrid nanoflowers promoting the robustness of D-allulose 3-epimerase

Enzyme-based hybrid nanoflowers, a green biocatalyst technology employing metal ions as the main driving force of enzyme immobilization without participating in the catalytic reaction, have been extensively explored to increase enzyme robustness. Here, a customized self-assembled protein-bimetallic hybrid nanoflower system (HNF) was designed to immobilize D-allulose 3-epimerase (DAEase) with a hierarchical flower-like architecture. The tailored DAEase-HNFs were extremely stable in acidic conditions, retaining more than 70 % of their initial activity after incubation in aqueous solution at pH 3.0–6.0 for 4 h. They were also durable, retaining 92.4 % relative activity after 8 consecutive cycles, and maintaining 82.3 % relative activity after storage for 30 days at 4 °C. Molecular dynamics (MD) simulations were performed to probe the self-assembly processes related to the increased robustness of the encapsulated DAEase by investigating the conformational changes in the gating switch helix of the substrate entrance, hydrogen bond networks, and the catalytic cavity. Our data indicate that HNFs are a promising immobilization strategy to improve the robustness and durability of DAEase.

Rational design of hollow flower-like MoS2/Mo2C heterostructures in N-doped carbon substrate for synergistically accelerating adsorption-electrocatalysis of polysulfides in lithium sulfur batteries

Lithium–sulfur (Li–S) batteries have been garnered significant attention in the energy storage field due to their high theoretical specific capacity and low cost. However, Li–S batteries suffer from issues like the shuttle effect, poor conductivity, and sluggish chemical reaction kinetics, which hinder their practical development. Herein, a novel hollow flower-like architecture composed of MoS2/Mo2C heterostructures in N-doped carbon substrate (H-Mo2S/Mo2C/NC NFs), which were well designed and prepared through a calcination-vulcanization method, were used as high-efficiency catalyst to propel polysulfide redox kinetics. Ex situ electrochemical impedance spectroscopy verify that the abundant heterojunctions could facilitate electron and ion transfer, revealed the excellent interface solid–liquid–solid conversion reaction. The adsorption test of Li2S6 showed that Mo2S and Mo2C formed heterostructure generate the binding of polysulfide could be enhanced. And cyclic voltammetry test indicate boost the polysulfide redox reaction kinetics and ion transfer of H-Mo2S/Mo2C/NC/S NFs cathode. Benefiting from the state-of-the-art design, the H-Mo2S/Mo2C/NC/S NFs cathode demonstrates remarkable rate performance with a specific capacity of 1351.9 mAh g−1 at 0.2 C, when the current density was elevated to 2 C and subsequently reverted to 0.2 C, the H-Mo2S/Mo2C/NC/S NFs cathode retained a capacity of 1150.4 mAh g−1, and it maintains exceptional long cycling stability (840 mA h g−1 at 2 C after 500 cycles) a low capacity decay of 0.0073% per cycle. This work presents an effective approach to rapidly fabricating multifunctional heterostructures as an effective sulfur host in improving the polysulfide redox kinetics for lithium sulfur batteries.

Porous Flower-Like Nanoarchitectures Derived from Nickel Phosphide Nanocrystals Anchored on Amorphous Vanadium Phosphate Nanosheet Nanohybrids for Superior Overall Water Splitting.

Transition metal phosphides (TMPs) and phosphates (TM-Pis) nanostructures are promising functional materials for energy storage and conversion. Nonetheless, controllable synthesis of crystalline/amorphous heterogeneous TMPs/TM-Pis nanohybrids or related nanoarchitectures remains challenging, and their electrocatalytic applications toward overall water splitting (OWS) are not fully explored. Herein, the Ni2P nanocrystals anchored on amorphous V-Pi nanosheet based porous flower-like nanohybrid architectures that are self-supported on carbon cloth (CC) substrate (Ni2P/V-Pi/CC) are fabricated by conformal oxidation and phosphorization of pre-synthesized NiV-LDH/CC. Due to the unique microstructures and strong synergistic effects of crystalline Ni2P and amorphous V-Pi components, the obtained Ni2P/V-Pi/CC owns abundant active sites, suitable surface/interface electronic structure and optimized adsorption-desorption of reaction intermediates, resulting in outstanding electrocatalytic performances toward hydrogen and oxygen evolution reactions in alkaline media. Correspondingly, the assembled Ni2P/V-Pi/CC||Ni2P/V-Pi/CC electrolyzer only needs an ultralow cell voltage (1.44V) to deliver 10mA cm-2 water-splitting currents, exceeding its counterparts, recently reported bifunctional catalysts-based devices, and Pt/C/CC||IrO2/CC pairs. Moreover, the Ni2P/V-Pi/CC||Ni2P/V-Pi/CC manifests remarkable stability. Also, such device shows a certain prospect for OWS in acidic media. This work may spur the development of TMPs/TMPis-based nanohybrid architectures by combining structure and phase engineering, and push their applications in OWS or other clean energy options.

Structure, optical and visible-light photocatalytic performance of Mo1-xCoxS2 (0 ≤ x ≤ 0.1) nanoparticles synthesized by facile hydrothermal method for methylene blue dye degradation

Mo1-xCoxS2 (0 ≤ x ≤ 0.1) nanoparticles were successfully synthesized by using a hydrothermal route. The crystal structure of the prepared samples was investigated by Xray diffraction (XRD), emphasizing that all the prepared samples had a hexagonal structure of MoS2, and revealed an increment in the average particle size from 5 to 8 nm with increasing the cobalt ratio. The morphology was examined using scanning electron microscopy (SEM), and the recorded images of pure and cobalt-doped MoS2 show flowerlike architecture clusters. FT-IR spectroscopy was carried out to detect functional groups and stretching and bending vibrations of chemical bonds existing in all the prepared samples, confirming the presence of Mo-O and Co-O-Co characteristic peaks. The chemical composition of the synthesized samples was determined by energy dispersive Xray (EDX) analysis. The results confirmed the presence of Mo, S, and Co, which are consistent with the proposed formation of Mo1-xCoxS2 nanosystems. Optical properties were examined by UV–Visible spectrophotometry, reflecting allowed direct transitions with an energy band gap that decreases from 1.9 eV to 1.53 eV with increasing cobalt concentration. The photocatalytic degradation efficiency of methylene blue (MB) using pure and different ratios of cobalt-doped MoS2 as catalysts was tested under visible light radiation, and it was noticed that the MB degradation increased with increasing cobalt concentration.

3D flower-like Cu-BiOCl/Bi2S3 heterostructure with synergistic Cu ion doping: A study on efficient tetracycline degradation under visible light

In this study, a novel three-dimensional, flower-like Cu-BiOCl/Bi2S3 photocatalyst was synthesized using a two-step calcination and hydrothermal method, aiming at the efficient removal of tetracycline (TC). Through comprehensive characterization techniques, it was discerned that the incorporation of Cu ions extended the light absorption range of BiOCl. Additionally, the formation of a heterojunction significantly enhanced the separation efficiency of space charge. The unique three-dimensional flower-like architecture of the Cu-BiOCl/Bi2S3 photocatalyst augments its surface area exposure and consequently, the density of active sites. This catalyst exhibited a remarkable degradation rate of approximately 95% for TC under visible light irradiation. This performance exhibits a notable enhancement over the degradation rates of BiOCl and Bi2S3, which are approximately 39% and 53% respectively, surpassing them by factors of 2.39 and 1.78. Electron spin resonance (ESR) analysis coupled with free radical trapping experiments pinpointed superoxide radicals (•O2-) and photogenerated holes (h+) as the pivotal active species orchestrating the photocatalytic degradation. Concludingly, a possible TC degradation pathway was proposed based on the intermediates generated during the photocatalytic reaction as detected by Liquid Chromatograph Mass Spectrometer (LC-MS) and Three-Dimension Excitation Emission Matrix (3D EEM).

Simultaneous Morphology and Band Structure Manipulation of BiOBr by Te Doping for Enhanced Photocatalytic Oxygen Evolution.

The photocatalytic oxygen evolution of bismuth oxybromide (BiOBr) is greatly hindered by its low visible-light response and high electron-hole recombination. Nonmetal doping can effectively alleviate these issues, leading to improvement in photocatalytic performance. Herein, Bi2Te3 was introduced as both the Te doping source and the morphology-control template to improve the photocatalytic performance of BiOBr. Appropriate amounts of Te are critical to maintain the ultrathin plate-like structure of BiOBr, whereas excessive Te results in the formation of a flower-like architecture. Oxygen evolution activity disclosed that a plate-like structure is essential for realizing higher performance owing to sufficient light utilization and efficient charge separation. An optimal oxygen evolution rate of 368.0 μmol h-1 g-1 was achieved for the Te-doped sample, which is 2.3-fold as that of the undoped BiOBr (158.9 μmol h-1 g-1). Theoretical calculations demonstrated that Te doping can induce impurity levels above the valence band of BiOBr, which slightly narrowed the band gap and strengthened the light absorption in the range of 400-800 nm. More importantly, Te dopants could act as shallow traps for confining the excited electrons, thus prolonging the carrier lifetime. This work provides a novel strategy to prepare highly efficient photocatalysts by simultaneously realizing morphology manipulation and nonmetal doping.

Defect-engineered Ni-Fe-LDH with porous flower-like architecture enables boosted advanced oxidation processes: Experimental and theoretical studies

In this paper, oxygen vacancies (VO) enriched flower-like Ni-Fe layered double hydroxide (VO-Ni-Fe-LDH) was prepared for activating peroxymonosulfate (PMS) to remove Tetracycline hydrochloride (TC). Sufficient experimental exploration and density functional theory (DFT) calculations clearly demonstrated the 3D morphology prevented the aggregation of VO-Ni-Fe-LDH and VO alter the electronic state of the surface. Thus, VO-Ni-Fe-LDH/PMS not only showed a 4 times enhancement in the reaction rate constant in comparison to Ni-Fe-LDH/PMS, but also exhibited a stable and efficient performance in continuous flow experiment up to 4.5 h. Quenching test and EPR experiments proved that degradation of TC was dominated by singlet oxygen (1O2), rather than sulfate radicals or hydroxyl radicals found by traditional LDH catalysts. The Chemical intermediates in TC oxidation process were identified through liquid chromatography-mass spectrophotometry, and degradation paths were provided for system optimization. In application, the VO-Ni-Fe-LDH/PMS system was able to withstand the effects of the water matrix, various pH values and remove the contaminants from real hospital wastewater with efficiency. This work emphasized the significance of rational architectural design combined with defect engineering in catalyst development, which holds the potential for advanced catalysis.

Synergistic interaction of S anions with 3d electrons in the bismuth sulfide/iron sulfide interface for simultaneous overall water splitting, urea oxidation, and methanol oxidation

Lotus-flower-like heterostructures of Bi2S3/FeS with diverse morphologies and stoichiometries were successfully synthesized using a facile hydrothermal technique. The flower-like architecture and FeS content were controlled by adjusting the amount of l-cysteine during precursor synthesis. Electrochemical properties were explored through a combination of Raman and impedance spectroscopy, revealing the relationship between catalytic performance and the stoichiometry of Bi2S3/FeS. Due to the synergistic interaction of S anions with 3d electrons at the Bi2S3/FeS interface the heterostructures exhibited highly enriched overall water-splitting ability, achieving a remarkably low cathodic and anodic overpotential of 36 and 230 mV for a current density of 10 mA/cm2. Furthermore, the addition of methanol and urea in the electrolyte further enhanced the catalytic efficiency of Bi2S3/FeS, achieving a very high current density of 100 mA/cm2 at exceptionally low potentials of 1.5 V and 1.43 V for methanol and urea oxidation reaction. The excellent electrocatalytic properties of Bi2S3/FeS were attributed to the interactions and interfacial effects between Bi2S3 and FeS, leading to enhanced surface roughness, inhomogeneity, and the creation of additional electrochemically active sites. Notably, Bi2S3/FeS demonstrated long-term stability and excellent mass transportation capabilities, highlighting its potential for various practical applications. The remarkable element gradient in the heterostructures further contributes to their superior performance, making them highly promising candidates for diverse applications.

Hierarchical porous nickel tin sulfide nanosheets as a binder free electrode for hybrid supercapacitor

The utilization of free-standing sulfide-based hybrid nanostructures plays a paramount role in supplying the steadily increasing demand for energy storage devices. Herein, this report presents the growth of outstanding binder-free Ni-Sn sulfide thin films for high-performance supercapacitors via the revised successive ionic layer adsorption and reaction (r-SILAR) method. Molar concentration ratios between Ni/Sn have been studied, and the optimum designed mesoporous Nix-Sn1.0xS/Ni foam (NF), a single cathode electrode material, successfully achieved outstanding specific capacitance of 2890 F/g at 5 A/g, capacitance retention of 85 %, and coulombic efficiency of 100 % after 10,000 cycles. Moreover, the constructed Nix-Sn1.0xS/NF//activated carbon (AC) hybrid supercapacitor device delivers an ultrahigh power density of 53.469 KW/Kg and capacitance retention of 95 % with robust long-term cycling stability up to1000 cycles. The superior electrochemical performance of the prepared Nix-Sn1.0xS electrode could be attributed to: (i) the synergistic effect of the two binary metal sulfides (Ni/Sn) into reversible faradaic redox reaction; (ii) the growing mechanism of the ultra-thin film (1.2 nm) as a binder-free electrode, enhance the ions insertion/extraction, and (iii) the formation of hierarchically flower-like architecture with uniform mesopores provides a high surface area (62.2 m2/g) and intensifies active sites for faradaic redox reactions. These encouraging results present a novel avenue for constructing advanced free-standing electrode materials for high-performance supercapacitors.