Nanocomposite Interface Research Articles

Self-assembling behavior and interface structure in vertically aligned nanocomposite (Pr0.5Ba0.5MnO3)1-x:(CeO2)x films on (001) (La,Sr)(Al,Ta)O3 substrates

Heteroepitaxial oxide-based nanocomposite films possessing a variety of functional properties have attracted tremendous research interest. Here, self-assembled vertically aligned nanocomposite (Pr0.5Ba0.5MnO3)1-x:(CeO2)x (x = 0.2 and 0.5) films have been successfully grown on single-crystalline (001) (La,Sr)(Al,Ta)O3 substrates by the pulsed laser deposition technique. Self-assembling behavior of the nanocomposite films and atomic-scale interface structure between Pr0.5Ba0.5MnO3 matrix and CeO2 nanopillars have been investigated by advanced electron microscopy techniques. Two different orientation relationships, (001)[100]Pr0.5Ba0.5MnO3//(001)[1-10]CeO2 and (001)[100]Pr0.5Ba0.5MnO3//(110)[1-10]CeO2, form between Pr0.5Ba0.5MnO3 and CeO2 in the (Pr0.5Ba0.5MnO3)0.8:(CeO2)0.2 film along the film growth direction, which is essentially different from vertically aligned nanocomposite (Pr0.5Ba0.5MnO3)0.5:(CeO2)0.5 films having only (001)[100]Pr0.5Ba0.5MnO3//(001)[1-10]CeO2 orientation relationship. Both coherent and semi-coherent Pr0.5Ba0.5MnO3/CeO2 interface appear in the films. In contrast to semi-coherent interface with regular distribution of interfacial dislocations, interface reconstruction occurs at the coherent Pr0.5Ba0.5MnO3/CeO2 interface. Our findings indicate that epitaxial strain imposed by the concentration of CeO2 in the nanocomposite films affects the self-assembling behavior of the vertically aligned nanocomposite (Pr0.5Ba0.5MnO3)1-x:(CeO2)x films.

Micro-Mechanism Research into Molecular Chains Orientation Synergistically Induced by Carbon Nanotube and Shear Flow in Injection Molding

For the degree of orderly arrangement of the molecular chains at the interface of nanocomposites, the static and sheared polyethylene (PE)/carbon nanotube (CNT) models and the sheared pure PE model were constructed, and molecular simulation experiments were carried out in comparison. The micro-mechanism of molecular chains orientation, synergistically induced by the carbon nanotube and shear flow in injection molding, was discussed by analyzing the radius of gyration, molecular chain motion, conformation evolution of molecular chains, bond orientation parameter, interface binding energy and atom distribution. The results show that, for the static composite system, the conformation adjustment of PE molecular chains induced by CNT is limited due to the hindrance from the surrounding chains. Thus, the orientation and radius of gyration of molecular chains increase slightly. For the sheared pure PE system, the orientation induced by shear flow is unstable. After the cessation of shear, the molecular chains undergo intense thermal movement and relax quickly. The disorientation is obvious, and the radius of gyration decreases considerably. It is worth noting that for the sheared composite system, shear flow and the CNT have a synergistic effect on the orientation of the molecular chains, which is due to the adsorption effect of the CNT on shear-induced oriented chains and the inhibition effect of CNT on the relaxation of shear-induced oriented chains. Thus, the orientation stability of PE chains is greatly improved, and interface crystallization is promoted. Moreover, because of the more regular arrangement of molecular chains in the sheared composite system, more H atoms and C atoms are close to the surface of the CNT, which increases the van der Waals force, and correspondingly increases the interface binding energy.

MOLECULAR DYNAMICS STUDIES ON THE STRENGTH PREDICTION OF INTERFACE BETWEEN AL-AL4C3 IN METAL MATRIX NANOCOMPOSITES

In this study, molecular dynamics simulations (MD) will be applied to modelling the Al4C3-aluminum interface in aluminum nanocomposite, Al4C3 is an interface that results from the shaker mill process which becomes a bridge that plays an important role in Carbon particles with Aluminium Matrix and Based on observations from the TEM characterization, it is found that the relationship between Al orientation to Al4C3 is (111) (002) (220). The characteristics of the interface between Aluminum matrix and Al4C3 will be analyzed using uniaxial tension and shear test simulation. The atomic potential used in this simulation is the embedded atomic method (EAM) for Al, empirical-order intermolecular potential (AIREBO) for C and lennard jones for the reaction of Al-C atom. The result shows that, the interface orientation is Al matrix (002) || Al4C3 (003) has the highest interface strength compared to Al matrix (111) || Al4C3 (003) and Al matrix (200) Interface orientation || Al4C3 (003). Results from the molecular dynamics simulations are also discussed with analytical results obtained experimental

MOLECULAR DYNAMICS STUDIES ON THE STRENGTH PREDICTION OF INTERFACE BETWEEN AL-AL4C3 IN METAL MATRIX NANOCOMPOSITES

In this study, molecular dynamics simulations (MD) will be applied to modelling the Al4C3-aluminum interface in aluminum nanocomposite, Al4C3 is an interface that results from the shaker mill process which becomes a bridge that plays an important role in Carbon particles with Aluminium Matrix and Based on observations from the TEM characterization, it is found that the relationship between Al orientation to Al4C3 is (111) (002) (220). The characteristics of the interface between Aluminum matrix and Al4C3 will be analyzed using uniaxial tension and shear test simulation. The atomic potential used in this simulation is the embedded atomic method (EAM) for Al, empirical-order intermolecular potential (AIREBO) for C and lennard jones for the reaction of Al-C atom. The result shows that, the interface orientation is Al matrix (002) || Al4C3 (003) has the highest interface strength compared to Al matrix (111) || Al4C3 (003) and Al matrix (200) Interface orientation || Al4C3 (003). Results from the molecular dynamics simulations are also discussed with analytical results obtained experimental

Interfaces in biopolymer nanocomposites: Their role in the gas barrier properties and kinetics of residual solvent desorption

Poly(lactic acid) nanocomposite films were prepared by solvent casting method dispersing lauryl-functionalized cellulose nanocrystals in the biopolymer matrix. The gas transport properties of nanocomposites with different filler content were studied by gas phase permeation technique while the release of residual solvent molecules (CHCl3) was analyzed by Thermal Desorption Spectroscopy. The aim of this work is to study the correlations between the two processes that so far were studied separately. The analysis reveals that both the gas barrier properties of the nanocomposite and the kinetics of the residual solvent desorption are controlled by interface LNC-PLA layers. The improved gas barrier properties observed up to a critical filler content of 6.5 wt. % are attributed to the formation of a gas-impermeable PLA regions with thickness in the 10 nm order surrounding the functionalized filler particles. In the pure PLA matrix residual solvent molecules form small aggregates which desorb through a thermally activated process showing a peak at T = 393 K and following a zero-order kinetic process. In the nanocomposites, interface regions trap a fraction of residual solvent molecules that increases with the LNC content: solvent release occurs at higher temperatures and follows a first-order desorption kinetics.

Hot-pressed graphene nanoplatelets or/and zirconia reinforced hybrid alumina nanocomposites with improved toughness and mechanical characteristics

This work explains the synergistic contribution of graphene nanoplatelets (GNP) and zirconia ceramic nanoparticles (ZrO2) on the microstructure, mechanical performance and ballistic properties of the alumina (Al2O3) ceramic hybrid nanocomposites. Over the benchmarked monolithic alumina, the hot-pressed hybrid nanocomposite microstructure demonstrated 68% lower grain size due to grain pinning phenomenon by the homogenously distributed reinforcing GNP (0.5 wt%) and zirconia (4 wt%) inclusions. Moreover, the hybrid nanocomposite manifested 155% better fracture toughness (KIC) and 17% higher microhardness as well as 88% superior ballistic trait over the monolithic alumina, respectively. The superior mechanical and ballistic performance of the hybrid nanocomposites was attributed to the combined role of zirconia nanoparticles and GNP nanomaterial in refining the microstructure and inducing idiosyncratic strengthening/toughening mechanisms. Extensive combined electron microscopy revealed complicated physical interlocking of the GNP into the microstructure as well as excellent bonding of the GNP with alumina at their interface in the hybrid nanocomposites. We also probed the efficiency of the pull-out and crack-bridging toughening mechanisms through proven quantitative methods. Based on the information extracted from the in-depth SEM/TEM investigation, we outlined schematic models for understating the reinforcing ability as well as toughening mechanisms in the hybrid nanocomposites and meticulously discussed. The hot-pressed hybrid nanocomposites owning high toughness and hardness may have applications in advanced armor technology.

CF4 plasma-fluorinated nano-SiC promotes the charge transfer in the interface of epoxy nanocomposites

Insulation failure and surface flashover of nanocomposites insulator caused by charge accumulation remain to be major hurdles in the application of high voltage equipment. In this study, we develop a plasma fluorination treatment method to graft fluorinated functional groups onto the surface of nano-SiC, in order to change the interfacial characteristics of the nanocomposites and promote charge transfer. Surface potential measurement and volume conductivity measurement are performed to evaluate charge transfer in the nanocomposites. When the concentration of fluorinated nano-SiC is 5 wt.%, the surface decay rate of the sample is larger than that of samples doped with less nanofiller, and the initial surface charge density is 79.8% that of the undoped sample. Furthermore, the fluorinated nano-SiC/epoxy nanocomposites show larger volume conductivity because of the introduction of CF3 functional groups, which influences the interfacial characteristics and promotes charge transfer in the interfacial regions of the nanocomposites. This work demonstrates the effect of charge transfer on surface flashover of the nanocomposites and the plasma fluorination treatment of nanoparticles is a novel approach to promote charge transfer and boost surface electrical performance of nanocomposites.

The Side‐Chain Liquid Crystalline Epoxy Polymer Grafted Nanoparticles for the Thermal and Mechanical Enhancement of Epoxy Nanocomposites

AbstractIn order to enhance the dispersion and the interface in epoxy nanocomposites filled nanoparticles, a novel side‐chain liquid crystalline epoxy polymer (SLCEP) was synthesized. The SLCEP grafted to alumina (Al2O3) surfaces via the carboxyl group for dispersing nanoparticles, bonded covalently with the epoxy matrix by the epoxy group for interface improvement and maintained good liquid crystal properties by the mesogenic unit. The dispersity of Al2O3 in Al2O3‐SLCEP and epoxy nanocomposites were studied by Fourier transform infrared imaging system and field emission scanning electron microscopy. The interface of epoxy nanocomposites was researched by observing the fracture morphology. By preventing the agglomeration of Al2O3 and strengthening its interfacial bonding with the matrix, the glass transition temperature and thermal stability of Al2O3‐SLCEP/epoxy nanocomposites were improved distinctly, and Al2O3‐SLCEP/epoxy nanocomposites were much superior to neat epoxy in mechanical properties. The excellent performance of SLCEP modified nanoparticles in epoxy demonstrates that is an effective general approach for nanoparticle/polymer.

The effect of the interface on magnetic properties of perovskite-spinel nanocomposites

In this research, perovskite-spinel nanocomposite with formula (x)(Cuo.3Mn0.7Fe2O4)- (1-x)(La0.9o Bi0.10 FeO3); 0 ≤ x ≤ 1, were prepared by the auto-combustion method. A single phase of orthorhombic and cubic structure for La0.9oBi0.10FeO3(LBFO); Cuo.3Mn0.7Fe2O4(CMFO) respectively have been proved for two parents and nanocomposites without any further secondary phase using XRD analysis. High-resolution transmission electron microscopy (HRTEM) images reveal nearly spherical nanoparticles for the parents and agglomerated for nanocomposites. Magnetic hysteresis loops demonstrate ferromagnetic (FM) behavior for the spinel compound and nanocomposite, where LBFO possesses G-type antiferromagnetic (AFM). Competition between FM and AFM phases lead to enhancement in magnetic parameters such as saturation magnetization (Ms), remnant magnetization (Mr) and coercivity (Hc). The magnetic properties at low temperatures show the decrease in magnetization and coercivity with increasing the temperature while the magnetic exchange bias HEB was increased until T=200 K and then decreased. The existence of intergranular magnetostatic interactions between the LBFO and CMFO interact at the interface of nanocomposites and play a decisive role in strain energy, exchange energy, and magnetic anisotropy

Dyakonov surface waves at the interface of nanocomposites with spherical and ellipsoidal inclusions

The dispersion properties of different types of surface electromagnetic waves which are supported by the interface of two nanocomposite materials with inclusions of different shape are studied theoretically and numerically. Both nanocomposites are made of doped n-type semiconductor inclusions which are evenly distributed in a transparent dielectric matrix. First nanocomposite contains semiconductor inclusions of spherical shape and can be represented as isotropic material with scalar effective dielectric permittivity. Second nanocomposite contains semiconductor inclusions of ellipsoidal shape and can be modeled as a uniaxial anisotropic crystal with two different principal effective permittivity components. Influence of physical and geometrical parameters of the nanocomposites on dispersion properties of surface waves is studied. It is shown that when dissipations in the semiconductor inclusions are taken into account the angular spectrum of Dyakonov surface wave existence becomes wider, and several dispersion curves of surface modes can simultaneously exist.

Efficient double electrochemiluminescence quenching based label-free highly sensitive detection of haptoglobin on a novel nanocomposite modified carbon nanofibers interface

ECL behaviour is highly dependent on electrode surface, materials and dimensions. Therefore, in this work ECL intensity of [Ru(bpy)3]2+/TPrA system was studied with the bare carbon nanofiber screen-printed electrode (CNFs-SPE) and the novel AuNPs/CdTe-QDs/SWCNTs/Chitosan nanocomposite modified CNFs-SPE (CdTe/AuNPs/SWCNTs/Chitosan/CNFs-SPE). ECL intensity was enhanced about 1.0 time with the AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE interface in comparison to the bare CNFs-SPE. Additionally, AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE interface produced ~ 200% increase both in electronic conductivity and in effective surface area in comparison to the bare CNFs-SPE. AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE interface with a combined advantage of high effective surface area, electronic conductivity and ECL intensity was for the first time used to develop an efficient double ECL quenching based immunosensor for the highly sensitive and selective label-free detection of haptoglobin (Hp). Under optimum conditions, the constructed Hp-immunosensor displayed a wide: 100 fg mL−1 to 10 ng mL−1 linear detection range, with a low limit of detection 100 fg mL−1. The calibration plot provides a negative linear relationship between log[c] of Hp and ECL intensity with a coefficient of correlation 0.99. Moreover, this novel biocompatible nanocomposite interface could be used for the ECL based detection of other biomarkers and biomolecules.

Effect of graphene oxide on the mechanical and thermal properties of graphene oxide/hytrel nanocomposites

Polymer nanocomposites offer enhancement in thermomechanical and physicochemical properties of polymers with the presence of a little amount of nanostructured fillers such as carbon nanotubes, graphene, and layered silicates. A facile and rapid preparation of hytrel (HTL)-graphene oxide (GO) nanocomposites is done via a solution mixing method. The influence of GO content (0.1, 0.5, 1, 2, and 5 wt%) on mechanical and thermal properties of GO/HTL nanocomposites has been evaluated by using various techniques such as tensile testing, thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The thermal stability and mechanical properties of GO/HTL nanocomposites were increased with increasing GO content. The composites have valuable improvement in tensile strength (139%) and storage modulus (72%) for HTL composite containing 5 wt% GO. The incorporation of GO into HTL polymer shows enhancement in thermal and mechanical properties due to the presence of strongest noncovalent interaction (π–π stacking) between the interface of nanocomposites. These enhanced physical properties of GO/HTL composites show its potential use in structural application.

Recent Advances in Characterization Techniques for the Interface in Carbon Nanotube-Reinforced Polymer Nanocomposites

The current state of characterization techniques for the interface in carbon nanotube-reinforced polymer nanocomposites is reviewed. Different types of interfaces that exist within the nanocomposites are summarized, and current efforts focused on understanding the interfacial properties and interactions are reviewed. The emerging trends in characterization techniques and methodologies for the interface are presented, and their strengths and limitations are summarized. The intrinsic mechanism of the interactions at the interface between the carbon nanotubes and the polymer matrix is discussed. Special attention is given to research efforts focused on chemical functionalization of carbon nanotubes. The benefits and disadvantages associated with covalent and noncovalent functionalization methods are evaluated, respectively. Various techniques used to characterize the properties of the interface are extensively reviewed. How the mechanical and thermal properties of the nanocomposites depend on the physical and chemical nature of the interface is also discussed. Better understanding and design of the interface at the atomic level could become the forefront of research in the polymer community. Potential problems going to be solved are finally highlighted.

Direct Detection of Local Electric Polarization in the Interfacial Region in Ferroelectric Polymer Nanocomposites.

Ferroelectric polymer nanocomposites are widely used in capacitive energy storage, electrocaloric refrigeration, and mechanical energy harvesting due to their exceptional electric polarization property and ease of fabrication. It is generally considered that the abnormal performance of ferroelectric nanocomposites stems from the interfacial region between the polymer matrix and embedded nanoparticles. However, direct evidence of the distinct local electric polarization property at the interfacial region is not yet accessible. Herein, a modified Kelvin probe force microscopy (KPFM) method with nanoscale spatial resolution is reported for direct detection of local polarization property at the matrix/particle interface in ferroelectric nanocomposites. Typical ferroelectric nanocomposites are studied using the present method. It is quantitatively probed that the electric polarization at matrix/particle interfacial region is higher than the polymer matrix under applied electric fields. Taking into account the enhanced local electric polarization gauged by the modified KPFM, the dielectric property of ferroelectric polymer nanocomposites matches with bulk experimental characterizations, indicating that the established method is reliable. It is anticipated that the present method, opening up new possibilities in understanding the matrix/particle interfacial region, may help with judicious design and engineering of high-performance ferroelectric polymer nanocomposites.

Silver nanoparticles impregnated chitosan layered carbon nanotube as sensor interface for electrochemical detection of clopidogrel in-vitro

Continuous periodical monitoring of clopidogrel in physiological body fluids is indispensable in medical diagnosis of heart ailments and cardiovascular diseases. A highly sensitive electrochemical sensor has been fabricated with silver nanoparticles embedded chitosan-carbon nanotube hybrid composite (AgChit-CNT) as sensor interface for detection of the important anti-platelet drug, clopidogrel (CLP). Synthesized AgChit-CNT nanocomposite is examined by x-ray diffraction, Raman spectroscopy and field emission scanning electron microscopy for its chemical and structural characteristics. Crystalline silver nanoparticles of about 35 nm are well distributed in the composite and have formed continuous chain like linkages with CNTs all throughout. Electrochemical responses of the fabricated AgChit-CNT nanocomposite electrode for the determination of CLP have been examined by cyclic voltammetry and electrochemical impedance spectroscopy. The nanoAg patterned CNT nanocomposite interface acts as an excellent electron transfer mediator towards the oxidation of clopidogrel. Electrochemical determination of CLP was investigated by differential pulse voltammetry (DPV) and amperometric analysis under optimized conditions. The limit of detection by DPV and amperometry were 30 nM and 10 nM, respectively, and the time of the analysis is as low as 10 s. Practical applicability for determination in artificially prepared urine and pharmaceutical formulation has been examined with good recovery limits of 95.2 to 102.6%.

Molecular dynamics approach on the hygroelastic behavior of epoxy/graphene nanocomposites

Hygroscopic aging causes swelling, degradation of mechanical and interfacial properties in thermosetting epoxy polymers, which eventually lead to a fast fracture at the interface in nanocomposite. Since the epoxy is a widely used high performance thermoset polymer for aerospace structures, durability analysis is necessary for the sake of maintenance and stability of the structures. In this study, the hygroelastic behavior of pure epoxy and epoxy/graphene nanocomposite is investigated through atomistic molecular dynamics (MD) simulation. To determine the hygroelastic behavior of epoxy materials, amorphous molecular unit cells of pure epoxy and epoxy/graphene nanocomposites with its highest possible cross-linking ratio and moisture contents of 0 and 2 wt% are considered. Through the classical ensemble simulations, diffusion coefficient of water in matrix, coefficient of moisture expansion (CME) and elastic modulus of pure epoxy and epoxy/graphene nanocomposites are determined.

Nonlocal self-organization of long stacking faults from highly strained nanocomposite film of complex oxide

Elastic strain and defects are important key words for controlling structure and properties in films. While epitaxial strain and misfit dislocations have been discussed in conventional films, the evolution of strain and defect can be significantly varied by nanocomposite strain and complicated defects in oxides. In the present study, long stacking faults with a spacing of 5--30 nm and a length of $>500\phantom{\rule{0.16em}{0ex}}\mathrm{nm}$ were self-organized by ex situ annealing highly strained nanocomposite films of $\mathrm{YB}{\mathrm{a}}_{2}\mathrm{C}{\mathrm{u}}_{3}{\mathrm{O}}_{7--\ensuremath{\delta}}(\mathrm{YBCO})+\mathrm{BaM}{\mathrm{O}}_{3}\phantom{\rule{4pt}{0ex}}(M=\mathrm{Hf},\phantom{\rule{0.28em}{0ex}}\mathrm{Sn})$. It is surprising that the nonlocal nature of stacking faults, namely, the structural correlation over $>500\phantom{\rule{0.16em}{0ex}}\mathrm{nm}$, was observed in spite of the local configuration of the nanocomposite interface. This kind of structural variation was not observed in the pure $\mathrm{YBCO}$ film without nanorods, even when the same annealing was performed. A strain energy analysis showed that the stacking fault formation led to the strain energy minimum by reducing the nanocomposite strain. The layered structure of YBCO stacking faults and the large nanocomposite strain realized the present nonlocal self-organization, which is not observed in the conventional systems with epitaxial strain and misfit dislocations.

A highly sensitive electrochemical detection of human chorionic gonadotropin on a carbon nano-onions/gold nanoparticles/polyethylene glycol nanocomposite modified glassy carbon electrode

Human chorionic gonadotropin (hCG) is a key diagnostic marker of pregnancy and an important biomarker for diseases related to seminal system including hydatid pregnancy, trophoblastic cancer and orchic teratoma. Therefore, in this work, for the first time we have modified a glassy carbon electrode (GCE) with carbon nano-onions (CNOs) gold nanoparticles (AuNPs) and polyethylene glycol (PEG) nanocomposite for a highly sensitive and label-free detection of hCG. CNOs/AuNPs/PEG nanocomposite modified GCE shown 150% high electronic conductivity and 150% more surface area. Fabrication of the immunosensor at CNOs/AuNPs/PEG nanocomposite interface was studied using cyclic voltammetry (CV) and square wave voltammetry (SWV). Under optimum conditions, dose response curve was obtained from 0.1fgmL−1 to 1ngmL−1 by SWV technique using Fe[CN]6]3/4− redox probe. The calibration plot gives a negative linear relationship between log[concentration] of hCG and electrical current with a linear correlation coefficient of 0.99. Experimentally, a detection range 0.1fgmL−1 to 1ngmL−1 with a limit of detection 0.1fgmL−1 was obtained. This immunosensor demonstrated high sensitivity, selectivity, resistant to interference, reproducibility, stability and potential to be used with real samples at healthcare centers. CNOs/AuNPs/PEG nanocomposite interface may also be used to fabricate diagnostics devices for the detection of other biomarkers and protein of clinical significance.

Graphene-Based Nanocomposites for Efficient Photocatalytic Hydrogen Evolution: Insight into the Interface toward Separation of Photogenerated Charges.

Although the reduced graphene oxide (rGO) has been intensively applied for photocatalytic H2 evolution, no enough attention was given to study the interface between the photocatalyst and rGO, which is the key point to affect the transportation of the photogenerated electron. Herein, in order to research the heterojunction interface, a series of SrTiO3 photocatalysts with different crystal facets were fabricated to be loaded with the rGO for photocatalytic H2 evolution. The characterizationsand theory calculation verified that the rGO wasmainly anchored on the Ti-O bond of the SrTiO3 in the composite. Therefore, compared to the {001} facets sample, the {110} facets of the SrTiO3, which exposed more Ti and O atoms, could form a stronger bond with the rGO. Additionally, the density functional theory study deduced that the photoinduced electron could immigrate rapidly from the Ti-O bond to the rGO in the composite, which was in good agreement with the results of photoelectrochemical and photoluminescence experiments. Meanwhile,experimentally, the 1% wt rGO@SrTiO3 with {110} facets nanocomposite showed the superior photocatalytic H2 yield rate (3.82 mmol/h/g), which was 2.2 times and 3.2 times higher than that of the pure SrTiO3 with the same facets and 1% wt rGO@SrTiO3 with {001} facets, respectively. Both experiments and theoretical calculations unveiled that the synergetic effect of SrTiO3 facets engineering and the rGO loading effectively prompted the immigration of photoinduced electrons at the nanocomposite interface. This work provides a rational thinking of a high efficiency rGO-based heterogeneous photocatalysts for solar energy conversion.

Synthesis and structural properties of Mn-doped ZnO/Graphene nanocomposite

Zinc oxide (ZnO) is a promising metal oxide semiconductor with various applications, especially in the photocatalytic destruction of environmental pollutants. However, this nanoparticle has some limitations, such as poor dispersion, aggregation, and a wide energy gap. As such, the doping of metal oxide semiconductor has been strongly recommended. Addition of manganese (Mn) has proven effective in resolving these issues. On the other hand, addition of carbon-based materials (e.g., graphene) could improve the stability and photocatalytic efficiency of ZnO. Graphene oxide acts as an electron- transport and electron-acceptor agent, controlling the charge transfer in the ZnO/graphene nanocomposite interface. The present study aimed to synthesize manganese-doped graphene/ZnO nanocomposites and determine its structural properties. Some techniques were employed to characterize the prepared composites, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), dynamic light scattering (DLS), and zeta potential analysis. According to the FTIR analysis, the peak in the range of 3467 cm-1 was due to the presence of zinc groups in the graphene structure, and the peak observed at 439 cm-1 also indicated the presence of Mn in the compound. Furthermore, the results of AFM analysis showed that graphene to be a layered sheet with the mean thickness of 1.48 nanometers. The results of the DLS analysis showed the mean diameter of GO-ZnO-Mn to be 37 nanometers, which reduced after graphene modification. According to the findings, addition of Mn and ZnO to graphene could effectively result in doping.