Hetero Nanostructures Research Articles

Interface-Engineered MoSe2-Co9S8 Nanoheterostructures with Enhanced Charge Storage Performance for Supercapacitor Application.

Cobalt-based chalcogenides have emerged as fascinating materials for supercapacitor applications owing to the presence of various mixed valance oxidation states in their structure along with rich electrochemical properties. However, their limited stability and cyclic performance hinder their viability for practical use in supercapacitors. Herein, a facile hot injection colloidal route is demonstrated to design MoSe2-Co9S8 nanoheterostructures (NHSs), which entails the epitaxial growth of Co9S8 nanoparticles (NPs) over the basal planes of ultrathin MoSe2 nanosheets (NSs). The interfacial engineering of the basal planes of MoSe2 NSs with Co9S8 NPs regulates the electronic properties and defects at the interfaces and increases the overall specific surface area and conductivity. As a result, MoSe2-Co9S8 NHSs electrode unveils a substantially higher specific capacitance of 910.5 F g-1 at 1 A g-1current density surpassing their individual counterparts. In addition, it demonstrates worthy solidity, retaining ≈90% of its capacitance and coulombic efficiency of 93.3% after 10,000 charge-discharge cycles at a high charge-discharge current density of 15 A g-1. As a proof-of-concept, coin cells are fabricated using MoSe2-Co9S8 NHSs which show 93% Coulomb efficiency and 86% capacitance retention. This study would pave the way for designing transition metal dichalcogenides (TMDs) - derived NHSs with superior capacitive properties.

Molybdenum Disulfide Induced Phase Control Synthesis of Multi‐dimensional Co3S4‐MoS2 Heteronanostructures via Cation Exchange

AbstractPhase control over cation exchange (CE) reactions has emerged as an important approach for the synthesis of nanomaterials (NMs), enabling precise determination of their reactivity and properties. Although factors such as crystal structure and morphology have been studied for the phase engineering of CE reactions in NMs, there remains a lack of systematic investigation to reveal the impact for the factors in heterogeneous materials. Herein, we report a molybdenum disulfide induced phase control method for synthesizing multidimensional Co3S4‐MoS2 heteronanostructures (HNs) via cation exchange. MoS2 in parent Cu1.94S‐MoS2 HNs are proved to affect the thermodynamics and kinetics of CE reactions, and facilitate the formation of Co3S4‐MoS2 HNs with controlled phase. This MoS2 induced phase control method can be extended to other parent HNs with multiple dimensions, which shows its diversity. Further, theoretical calculations demonstrate that Co3S4 (111)/MoS2 (001) exhibits a higher adhesion work, providing further evidence that MoS2 enables phase control in the HNs CE reactions, inducing the generation of novel Co3S4‐MoS2 HNs. As a proof‐of‐concept application for crystal phase‐ and dimensionality‐dependent of cobalt sulfide based HNs, the obtained Co3S4‐MoS2 heteronanoplates (HNPls) show remarkable performance in hydrogen evolution reactions (HER) under alkaline media. This synthetic methodology provides a unique design strategy to control the crystal structure and fills the gap in the study of heterogeneous materials on CE reaction over phase engineering that are otherwise inaccessible.

Synthesis of Dumbbell-Like Heteronanostructures Encapsulated in Ferritin Protein: Towards Multifunctional Protein Based Opto-Magnetic Nanomaterials for Biomedical Theranostic

Dumbbell-like hetero nanostructures based on gold and iron oxides is a promising material for biomedical applications, useful as versatile theranostic agents due the synergistic effect of their optical and magnetic properties. However, achieving precise control on their morphology, size dispersion, colloidal stability, biocompatibility and cell targeting remains as a current challenge. In this study, we address this challenge by employing biomimetic routes, using ferritin protein nanocages as template for these nanoparticles’ synthesis. We present the development of an opto-magnetic nanostructures using the ferritin protein, wherein gold and iron oxide nanostructures were produced within its cavity. Initially, we investigated the synthesis of gold nanostructures within the protein, generating clusters and plasmonic nanoparticles. Subsequently, we optimized the conditions for the superparamagnetic nanoparticles synthesis through controlled iron oxidation, thereby enhancing the magnetic properties of the resulting system. Finally, we produce magnetic nanoparticles in the protein with gold clusters, achieving the coexistence of both nanostructures within a single protein molecule, a novel material unprecedented to date. We observed that factors such as temperature, metal/protein ratios, pH, dialysis, and purification processes all have an impact on protein recovery, loading efficiency, morphology, and nanoparticle size. Our findings highlight the development of ferritin-based nanomaterials as versatile platforms for potential biomedical use as multifunctional theranostic agents.

Molybdenum Disulfide Induced Phase Control Synthesis of Multi-dimensional Co3S4-MoS2 Heteronanostructures via Cation Exchange.

Phase control over cation exchange (CE) reactions has emerged as an important approach for the synthesis of nanomaterials (NMs), enabling precise determination of their reactivity and properties. Although factors such as crystal structure and morphology have been studied for the phase engineering of CE reactions in NMs, there remains a lack of systematic investigation to reveal the impact for the factors in heterogeneous materials. Herein, we report a molybdenum disulfide induced phase control method for synthesizing multidimensional Co3S4-MoS2 heteronanostructures (HNs) via cation exchange. MoS2 in parent Cu1.94S-MoS2 HNs are proved to affect the thermodynamics and kinetics of CE reactions, and facilitate the formation of Co3S4-MoS2 HNs with controlled phase. This MoS2 induced phase control method can be extended to other parent HNs with multiple dimensions, which shows its diversity. Further, theoretical calculations demonstrate that Co3S4 (111)/MoS2 (001) exhibits a higher adhesion work, providing further evidence that MoS2 enables phase control in the HNs CE reactions, inducing the generation of novel Co3S4-MoS2 HNs. As a proof-of-concept application for crystal phase- and dimensionality-dependent of cobalt sulfide based HNs, the obtained Co3S4-MoS2 heteronanoplates (HNPls) show remarkable performance in hydrogen evolution reactions (HER) under alkaline media. This synthetic methodology provides a unique design strategy to control the crystal structure and fills the gap in the study of heterogeneous materials on CE reaction over phase engineering that are otherwise inaccessible.

Colloidal Synthesis of Cu3N Nanorods and Construction of Cu3N-Cu2O Heteronanostructures via Epitaxial Growth.

The synthesis of transition metal nitrides nanocrystals (TMNs NCs) has posed a significant challenge due to the limited reactivity of nitrogen sources at lower temperatures and the scarcity of available synthesis methods. In this study, we present a novel colloidal synthesis strategy for the fabrication of Cu3N nanorods (NRs). It is found that the trace oxygen (O2) plays an important role in the synthesis process. And a new mechanism for the formation of Cu3N is proposed. Subsequently, by employing secondary lateral epitaxial growth, the Cu3N-Cu2O heteronanostructures (HNs) can be prepared. The Cu3N NRs and Cu3N-Cu2O HNs were evaluated as precursor electrocatalysts for the CO2 reduction reaction (CO2RR). The Cu3N-Cu2O HNs demonstrate remarkable selectivity and stability with ethylene (C2H4) Faradaic efficiency (FE) up to 55.3%, surpassing that of Cu3N NRs. This study provides innovative insights into the reaction mechanism of colloidal synthesis of TMNs NCs and presents alternative options for designing cost-effective electrocatalysts to achieve carbon neutrality.

Nitrogen Configuration Effects on Charge Carrier Dynamics in CsPbBr3/Carbon Dots S-Scheme Heterojunction for Photocatalytic CO2 Reduction.

Nitrogen-doped carbon dots (NCDs) featuring primary pyrrolic N and pyridinic N dominated configurations were prepared using hydrothermal (H-NCDs) and microwave (M-NCDs) methods, respectively. These H-NCDs and M-NCDs were subsequently applied to decorate CsPbBr3 nanocrystals (CPB NCs) individually, using a ligand-assisted reprecipitation process. Both CPB/M-NCDs and CPB/H-NCDs nanoheterostructures (NHSs) exhibited S-scheme charge transfer behavior, which enhanced their performance in photocatalytic CO2 reduction and selectivity of CO2-to-CH4 conversion, compared to pristine CPB NCs. The presence of pyrrolic N configuration at the heterojunction of CPB/H-NCDs facilitated efficient S-scheme charge transfer, leading to a remarkable 43-fold increase in photoactivity. In contrast, CPB/M-NCDs showed only a modest 3-fold enhancement in photoactivity, which was attributed to electron trapping by pyridinic N at the heterojunction. The study offers crucial insights into charge carrier dynamics within perovskite/carbon NHSs at the molecular level to advance the understanding of solar fuel generation.

Polarization‐Enhanced Narrow‐Band GeS2 2‐D SWIR Spectral Phototransistor

AbstractIntegrated computational spectrometers with gate‐tunable nano heterostructures and reconstruction algorithms are attractive for on‐chip gas‐sensing spectrometers and have enabled versatile spectrum detectors. However, they require the selective and optical filtering capabilities of wavelengths, restricting their efficient implementation in narrow‐band photodetection. In this study, a printable spectral phototransistor is developed with high dynamic detectivity (1012 Jones and 105 Hz at −3 db bandwidth) modulated by a GeS2 nanosheet heterostructure at short‐wave infrared (SWIR) regime. Using the transport mode switching of carriers in a heterostructure and the polarization‐sensitivity of the GeS2 two‐dimension (2‐D) nanosheet, this SWIR spectral phototransistor demonstrates an accurate narrow‐band selective (96.7% accuracy) spectrum detector and performed a deep‐learning analysis of an artificial neural network (ANN). Furthermore, this GeS2 2‐D based spectral phototransistor, characterized by its high in‐plane anisotropy and electrically reconfigurable properties, extends the applicability of narrow‐band photodetection with 15 nm Full Width at Half Maximum (FWHM) to the recognition of trace‐gases at the parts per billion (ppb) level.

Ternary heterostructure-driven photoinduced electron-hole separation enhanced oxidative stress for triple-negative breast cancer therapy

Zinc oxide nanoparticles (ZnO NPs) stand as among the most significant metal oxide nanoparticles in trigger the formation of reactive oxygen species (ROS) and induce apoptosis. Nevertheless, the utilization of ZnO NPs has been limited by the shallowness of short-wavelength light and the constrained production of ROS. To overcome these limitations, a strategy involves achieving a red shift towards the near-infrared (NIR) light spectrum, promoting the separation and restraining the recombination of electron-hole (e−-h+) pairs. Herein, the hybrid plasmonic system Au@ZnO (AZ) with graphene quantum dots (GQDs) doping (AZG) nano heterostructures is rationally designed for optimal NIR-driven cancer treatment. Significantly, a multifold increase in ROS generation can be achieved through the following creative initiatives: (i) plasmonic Au nanorods expands the photocatalytic capabilities of AZG into the NIR domain, offering a foundation for NIR-induced ROS generation for clinical utilization; (ii) elaborate design of mesoporous core-shell AZ structures facilitates the redistribution of electron-hole pairs; (iii) the incorporation GQDs in mesoporous structure could efficiently restrain the recombination of the e−-h+ pairs; (iv) Modification of hyaluronic acid (HA) can enhance CD44 receptor mediated targeted triple-negative breast cancer (TNBC). In addition, the introduced Au NRs present as catalysts for enhancing photothermal therapy (PTT), effectively inducing apoptosis in tumor cells. The resulting HA-modified AZG (AZGH) exhibits efficient hot electron injection and e−-h+ separation, affording unparalleled convenience for ROS production and enabling NIR-induced PDT for the cancer treanment. As a result, our well-designed mesoporous core-shell AZGH hybrid as photosensitizers can exhibit excellent PDT efficacy.

Novel Au/Cu2NiSnS4 Nano-Heterostructure: Synthesis, Structure, Heterojunction Band Offset and Alignment, and Interfacial Charge Transfer Dynamics.

Considering the importance of physics and chemistry at material interfaces, we have explored the coupling of multinary chalcogenide semiconductor Cu2NiSnS4 nanoparticles (CNTS NPs) for the first time with the noble metal (Au) to form Au-CNTS nano-heterostructures (NHSs). The Au-CNTS NHSs is synthesized by a simple facile hot injection method. Synergistic experimental and theoretical approaches are employed to characterize the structural, optical, and electrical properties of the Au-CNTS NHSs. The absorption spectra demonstrate enhanced and broadened optical absorption in the ultraviolet-visible-near-infrared (UV-Vis-NIR) region, which is corroborated by cyclic voltammetry (CV) readings. CV measurements show type II staggered band alignment, with a conduction band offset (CBO) of 0.21 and 0.23 eV at the Au-CNTS/CdS and CNTS/CdS interface, respectively. Complementary first-principles density functional theory (DFT) calculations predict the formation of a stable Au-CNTS NHSs, with the Au nanoparticle transferring its electrons to the CNTS. Moreover, our interface analysis using ultrafast transient absorption experiments demonstrate that the Au-CNTS NHSs facilitates efficient transport and separation of photoexcited charge carriers when compared to pristine CNTS. The transient measurements further reveal a plasmonic electronic transfer from the Au nanoparticle to CNTS. Our advanced analysis and findings will prompt investigations into new functional materials and their photo/electrocatalysis and optoelectronic device applications in the future.

Bi2S3/Ti3C2-TPP nano-heterostructures induced by near-infrared for photodynamic therapy combined with photothermal therapy on hypoxic tumors

BackgroundPhotodynamic therapy (PDT) efficacy of bismuth sulfide (Bi2S3) semiconductor has been severely restricted by its electron–hole pairs (e−−h+) separation inefficiency and oxygen (O2) deficiency in tumors, which greatly hinders reactive oxygen species (ROS) generation and further clinical application of Bi2S3 nanoparticles (NPs) in biomedicine.ResultsHerein, novel Bi2S3/titanium carbide (Ti3C2) two-dimensional nano-heterostructures (NHs) are designed to realize multimode PDT of synchronous O2 self-supply and ROS generation combined with highly efficient photothermal tumor elimination for hypoxic tumor therapy. Bi2S3/Ti3C2 NHs were synthesized via the in situ synthesis method starting from Ti3C2 nanosheets (NSs), a classical type of MXene nanostructure. Compared to simple Bi2S3 NPs, Bi2S3/Ti3C2 NHs significantly extend the absorption to the near-infrared (NIR) region and enhance the photocatalytic activity owing to the improved photogenerated carrier separation, where the hole on the valence band (VB) of Bi2S3 can react with water to supply O2 for the electron on the Ti3C2 NSs to generate ·O2− and ·OH through electron transfer. Furthermore, they also achieve 1O2 generation through energy transfer due to O2 self-supply. After the modification of triphenylphosphium bromide (TPP) on Bi2S3/Ti3C2 NHs, systematic in vitro and in vivo evaluations were conducted, revealing that the synergistic-therapeutic outcome of this nanoplatform enables complete eradication of the U251 tumors without recurrence by NIR laser irradiation, and it can be used for computed tomography (CT) imaging because of the strong X-ray attenuation ability.ConclusionThis work expands the phototherapeutic effect of Bi2S3-based nanoplatforms, providing a new strategy for hypoxic tumor theranostics.

Photo-Responsive Ascorbic Acid-Modified Ag2S-ZnS Heteronanostructure Dropping pH to Trigger Synergistic Antibacterial and Bohr Effects for Accelerating Infected Wound Healing.

Nonantibiotic approaches must be developed to kill pathogenic bacteria and ensure that clinicians have a means to treat wounds that are infected by multidrug-resistant bacteria. This study prepared matchstick-like Ag2S-ZnS heteronanostructures (HNSs). Their hydrophobic surfactants were then replaced with hydrophilic poly(ethylene glycol) (PEG) and thioglycolic acid (TGA) through the ligand exchange method, and this was followed by ascorbic acid (AA) conjugation with TGA through esterification, yielding well-dispersed PEGylated Ag2S-ZnS@TGA-AA HNSs. The ZnS component of the HNSs has innate semiconductivity, enabling the generation of electron-hole pairs upon irradiation with a light of wavelength 320 nm. These separate charges can react with oxygen and water around the HNSs to produce reactive oxygen species. Moreover, some holes can oxidize the surface-grafted AA to produce protons, decreasing the local pH and resulting in the corrosion of Ag2S, which releases silver ions. In evaluation tests, the PEGylated Ag2S-ZnS@TGA-AA had synergistic antibacterial ability and inhibited Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus (MRSA). Additionally, MRSA-infected wounds treated with a single dose of PEGylated Ag2S-ZnS@TGA-AA HNSs under light exposure healed significantly more quickly than those not treated, a result attributable to the HNSs' excellent antibacterial and Bohr effects.

3D Stem Cell Spheroids with 2D Hetero-Nanostructures for In Vivo Osteogenic and Immunologic Modulated Bone Repair.

3D stem cell spheroids have immense potential for various tissue engineering applications. However, current spheroid fabrication techniques encounter cell viability issues due to limited oxygen access for cells trapped within the core, as well as nonspecific differentiation issues due to the complicated environment following transplantation. In this study, functional 3D spheroids are developed using mesenchymal stem cells with 2D hetero-nanostructures (HNSs) composed of single-stranded DNA (ssDNA) binding carbon nanotubes (sdCNTs) and gelatin-bind black phosphorus nanosheets (gBPNSs). An osteogenic molecule, dexamethasone (DEX), is further loaded to fabricate an sdCNTgBP-DEX HNS. This approach aims to establish a multifunctional cell-inductive 3D spheroid with improved oxygen transportation through hollow nanotubes, stimulated stem cell growth by phosphate ions supplied from BP oxidation, in situ immunoregulation, and osteogenesis induction by DEX molecules after implantation. Initial transplantation of the 3D spheroids in rat calvarial bone defect shows in vivo macrophage shifts to an M2 phenotype, leading to a pro-healing microenvironment for regeneration. Prolonged implantation demonstrates outstanding in vivo neovascularization, osteointegration, and new bone regeneration. Therefore, these engineered 3D spheroids hold great promise for bone repair as they allow for stem cell delivery and provide immunoregulative and osteogenic signals within an all-in-one construct.

Multi-synergies of hollow CdS cubes on MoS2 sheets for enhanced visible-light-driven photocatalysis

Formation of intimate interfaces in semiconductor-based heteronanostructures (HNSs) is widely adopted to enhance the efficiency of photocatalytic hydrogen evolution via water splitting because of their efficient light harvesting, charge carrier separation, and transfer capability originating from intimate interface. Here, we employ a multi-step approach, involving the direct growth of the photocatalytically active semiconductor (Cu2O) on MoS2 sheets, along with anion exchange and cation exchange methods to design hollow CdS cube/MoS2 sheet HNSs (H-CdS/MoS2 HNSs) consisting of intimate interfaces between hollow CdS cubes and MoS2 sheets. These distinctive morphological and compositional features endow H-CdS/MoS2 HNSs with exceptional charge transfer capability, intrinsic catalytic activity, and light-harvesting capacity. Consequently, H-CdS/MoS2 HNSs demonstrate significantly enhanced photocatalytic performance and stability for hydrogen evolution reactions and pollutant degradation under visible light irradiation compared to their binary and unary photocatalyst counterparts. This design strategy demonstrates the significance of forming intimate interfaces using hollow semiconductors in HNSs for advanced photocatalysis.

Prevention of ion migration in lead halide perovskites upon plugging the anion vacancies with PbSe islands.

To circumvent the issue of halide ion exchange in perovskites, we have decorated CsPbBr3 and CsPbI3 nanocrystals with different sized PbSe nanoparticles and demonstrated that it effectively prevents anion exchange reaction in CsPbBr3/CsPbI3 nanoheterostructures (NHSs) as a consequence of halide vacancy passivation by the more covalent selenide anion.

The impressive photocatalytic performance of TiO2/CeCoO3/PMO-IL nanohybrid toward the selective generation of aldehydes under a visible-LED light source

The construction of perovskite-based wide bandgap semiconductors with uniform dispersion is one of the main strategies to improve the catalytic activity of semiconductor materials. Here, a heterojunction catalyst was obtained by nucleating TiO2 on CeCoO3 nanopowders and producing TiO2/CeCoO3 hetero nanostructures at 450 °C. Then by putting them on the PMO-IL as a porous substrate, TiO2/CeCoO3/PMO-IL nanohybrid was prepared. The properties of nanohybrid were characterized by FE-SEM, EDS, XRD, BET, XPS, HRTEM, SAED, FT-IR, DRS, and PL spectroscopy. The photocatalytic efficiency of TiO2/CeCoO3 and TiO2/CeCoO3/PMO-IL toward the selective fabrication of aldehydes was studied under the irradiation of visible light. The synthesized nanohybrid demonstrated excellent catalytic activity compared to TiO2/CeCoO3 and PMO-IL alone. Therefore, this nanohybrid could be used as a capable heterogeneous photocatalyst due to its high activity, selectivity, and recyclability.

Synthesis of Metal (Ni) Doped Metal Oxide (ZnO) Heteronanostructures and Investigation of Their Morphological-Optical Properties

In this study, different volumes of Nickel (Ni) doped Zinc oxide (ZnO) thin films were deposited on FTO by hydrothermal method. The films were characterized by SEM, EDS, and UV-Vis Spectroscopy. When the SEM images were examined, the nanostructures showed different morphological features as the amount of doped (v) nickel-ZnO increased in comparison to undoped nickel-ZnO. Furthermore, it was demonstrated that the obtained film surface has a homogeneous distribution. EDS spectra showed the increase in Ni by volume and its presence in the film composition. The UV-Vis Spectroscopy results showed that Ni doping can change the transmittance and band gap values from 2.94 to 3.38, and thus the ZnO band gap can be adjusted by Ni doping. As a result of the findings, ZnO-NiO thin films are promising candidates for both high-performance hetero nanostructures and practical applications.

Facile synthesis of green engineered CuO/Cu2O-C nano heterostructures with the controlled Cu2O content for the photodegradation of crystal violet

Copper oxide/cuprous oxide and carbon heterostructured nanocomposites (CuO/Cu2O-C NCs) were fabricated using an agro-biomass wheatgrass extract (WGE), presenting an innovative, eco-friendly, and facile green synthetic approach. The CuO/Cu2O-C nanocomposites engineered using WGE were extensively characterized using UV–Vis, IR, XRD, DLS, XPS, SEM, TEM, BET, and TGA characterization techniques. The synthesized CuO/Cu2O-C NCs were crystalline with a monoclinic phase and an average crystallite size of 32 nm, as confirmed by XRD. Tauc plots were utilized to calculate the band gap energies (2.05 and 1.53 eV). The synthetic procedure is optimized, and the effect of plant extract in the controlled synthesis of Cu2O content in the CuO/Cu2O-C NCs was investigated. These green CuO/Cu2O-C NCs were tested for photocatalytic activity. A detailed kinetic study was conducted to degrade pathological effluent crystal violet (CV). The nanocomposite with a higher concentration of Cu2O is potentially a superior photocatalyst and demonstrated an excellent synergistic action, removing around 80 % of the crystal violet stain in visible light. Apart from photodegradation, these CuO/Cu2O-C NCs were good antioxidants and displayed good antibacterial activity against the gram-positive and gram-negative bacterial strains. The key highlight of this work is the low-cost disruptive engineering strategy for synthesizing frugal nanomaterials for multifaceted applications.

Implementation of visible light-driven photocatalytic degradation of antibiotic chloramphenicol using Bi2S3/ZrO2 and Bi2WO6/ZrO2 heteronanostructures

Zirconium dioxide-incorporated bismuth sulfide (Bi2S3/ZrO2) and bismuth tungstate (Bi2WO6/ZrO2) heteronanostructures (HNSs) were fabricated to serve as photocatalysts for the visible light-driven degradation of antibiotic chloramphenicol (CAP). A two-step hydrothermal process was applied to synthesize HNSs, and their structural and optical properties were validated by several analytical techniques. Interestingly, a multi-structural feature was ascertained in which nanoflower-structured ZrO2 was attached to the surface of nanorod- and nanosheet-structured Bi2S3 and Bi2WO6, respectively, resulting in the formation of Bi2S3/ZrO2 and Bi2WO6/ZrO2 HNSs. For the photocatalytic degradation of CAP, both HNSs showed magnificent catalytic activity during a visible light-based photocatalytic degradation. Furthermore, when peroxymonosulfate (PMS) was used as an activator for an oxidative catalytic reaction, the photocatalytic degradation rate was drastically enhanced to nearly 5 times. Bi2S3/ZrO2 and Bi2WO6/ZrO2 showed ∼96 % CAP degradation in 15 min, with rate constants of 0.2511 and 0.2163 min−1, respectively. The synergistic effects of the substantial generation and separation of photoinduced charge carriers are responsible for the highly improved catalytic activity. Scavenger analysis demonstrated that hydroxyl radical species predominated in the effective degradation process. These kinds of inorganic-based HNSs are expected to rule the field of contaminated water remediation, which will also expand a platform for the fabrication of photocatalyst materials.

Novel Biocompatible Magnetoelectric MnFe2 O4 Core@BCZT Shell Nano-Hetero-Structures with Efficient Catalytic Performance.

Magnetoelectric (ME) small-scale robotic devices attract great interest from the scientific community due to their unique properties for biomedical applications. Here, novel ME nano hetero-structures based on the biocompatible magnetostrictive MnFe2 O4 (MFO) and ferroelectric Ba0.85 Ca0.15 Zr0.1 Ti0.9 O3 (BCZT) are developed solely via the hydrothermal method for the first time. An increase in the temperature and duration of the hydrothermal synthesis results in increasing the size, improving the purity, and inducing morphology changes of MFO nanoparticles (NPs). A successful formation of a thin epitaxial BCZT-shell with a 2-5nm thickness is confirmed on the MFO NPs(77 ± 14nm) preliminarily treated with oleic acid (OA) or polyvinylpyrrolidone (PVP), whereas no shell is revealed on the surface of pristine MFO NPs. High magnetization is revealed for the developed ME NPs based on PVP- and OA-functionalized MFO NPs (18.68 ± 0.13 and 20.74 ± 0.22 emug-1 , respectively). Moreover, ME NPs demonstrate 95% degradation of a model pollutant Rhodamine B within 2.5 h under an external AC magnetic field (150 mT, 100Hz). Thus, the developed biocompatible core-shell ME NPs of MFO and BCZT can be considered as a promising tool for non-invasive biomedical applications, environmental remediation, and hydrogen generation for renewable energy sources.

A durable gas sensor based on AgVO3/TiO2 nanoheterostructures to ethanol gas

Semiconductor metal oxides (MOS) have been hot research topics in the field of gas sensors. However, the applicability of MOS-based gas sensors is severely constrained by the low sensitivity, poor selectivity, and high working temperature. One-dimensional AgVO3/TiO2 nanoheterostructures (NHSs) were fabricated using a hydrothermal technique to address above issues. The resulting AgVO3/TiO2 NHSs-based chemo resistive gas sensor shows good selectivity to ethanol (EtOH) gas. Moreover, the AgVO3/TiO2 with a molar ratio of 1:1 (AT) shows the highest sensing performance. The sensitivity of AT to 100 ppm EtOH at 200 ℃ is evaluated as 46.3, which is 22.0 and 1.8 times greater than that of TiO2 and AgVO3, respectively. Especially, AT possesses good sensing performance at room temperature, and its sensitivity to 100 ppm EtOH is 1.2. Simultaneously, it exhibits fast response/recovery times (17/32 s) in EtOH gas detection and excellent stability after 50 continuous cycle tests and 50 days of cycle life testing. The gas sensing mechanism is systematically analyzed from the carrier transfer ability, the synergy of AgVO3 and TiO2, the heterojunction effect, and the morphology promotion. This work reports an excellent EtOH gas sensor based on the constructed AgVO3/TiO2 NHSs, providing an insight into the fabrication of MOS-based nanocomposites for effective EtOH detection.