Nanoscale Oxide Research Articles

Significant Reduction of the Dead Layers by the Strain Release in La0.7Sr0.3MnO3 Heterostructures.

Great efforts have been devoted to exploring the emergent phenomena occurring in heterostructures of correlated oxides. However, the presence of both magnetic and electrical dead layers in functional oxide films generally obstructs the device functionalization and miniaturization. Here, we demonstrate an effective strategy to significantly reduce the thickness of dead layers in a prototypical correlated oxide system, La0.7Sr0.3MnO3 (LSMO) grown on LaAlO3 (LAO) substrates, via strain engineering by inserting a Sr3Al2O6 buffer layer with a different thickness at heterointerfaces. In this way, the thicknesses of the magnetic and electrical dead layers of LSMO films on the LAO substrates notably decrease from 8 to 4 unit cells and from 13 to 9 unit cells, respectively. Our results provide a convenient method to minimize or even eliminate the dead layers of correlated oxides through the interfacial strain engineering, which has potential applications in nanoscale oxide spintronic devices.

Effect of oxide dispersoids on precipitation-strengthened Al-1.7Zr (wt %) alloys produced by laser powder-bed fusion

Binary Al-1.7 wt % Zr (Al-0.5 at % Zr) alloys, with and without 1 wt % (0.7 vol %) Al2O3 nanoparticle additions (80–100 nm), are fabricated by laser powder-bed fusion (L-PBF) from blends of Al, Zr, and Al2O3 powders. Elemental Zr, which is ~80 % dissolved in the melt pool, forms primary L12-Al3Zr precipitates upon solidification and is also retained in a supersaturated solid solution in the Al matrix. The primary L12-Al3Zr phase takes three forms: (i) discrete, micron-sized precipitates that nucleate fine Al matrix grains, (ii) elongated “strings” of submicron precipitates forming in highly enriched Zr regions, and (iii) < 100 nm precipitates within fine Al-grains. The Al2O3 nanodispersoid additions are either lost to slag or entrapped within Al-grains as oxide dispersoids, resulting in an oxide concentration of 0.46 wt % for the modified ODS alloy. Al2O3 nanoscale dispersoids (0.28 wt %) are also observed in the unmodified alloy, and are assumed to originate from (i) native oxides from the surface of the Al powder particles, and/or (ii) reaction with trace amounts of oxygen in the processing environment. The hardness upon aging at 400 °C reaches a peak value of ~750–850 MPa after 1.5 h, consistent with precipitation of secondary L12-Al3Zr nanoprecipitates. Upon overaging, hardness slowly decreases to 500 MPa (the as-processed value) after 1,500 h at 400 °C, with no difference observed between the Al-Zr and Al-Zr-Al2O3 alloys. Strengthening mechanisms combines Hall-Petch strengthening from micron-sized grains, Zr solid-solution strengthening, and secondary L12-Al3Zr precipitate strengthening, with slow precipitate coarsening and effective grain pinning by Al3Zr precipitates and oxide dispersoids located at grain boundaries. Creep resistance is comparable for both alloys, which show threshold stresses of ~15 and 6 MPa, at 300 and 400 °C respectively. Oxygen content analysis is recommended for all Al-based alloys fabricated via L-PBF due to the potential for non-reproducible nanoscale oxide inclusions (from native oxide on Al powders and from reaction with residual oxygen), which may affect the mechanical properties of the alloys, but are difficult to observe via SEM or TEM analysis.

A comparative study of microstructure and mechanical properties of ODS CrFeNi-based medium- and high-entropy alloys

Medium- and high-entropy alloys (MEAs and HEAs) intrigue extensive interest of worldwide scholars for their unique properties. In this paper, oxide dispersion strengthened (ODS) CrFeNi-based MEA and HEAs with 1 wt% Y2O3 and 1 wt% Zr addition were fabricated by mechanical alloying (MA) and spark plasma sintering (SPS). The differences between ODS-MEA and ODS-HEA in microstructure (especially nanoscale oxides) and mechanical properties were characterized and compared by XRD, XPS, BSE, HRTEM, STEM, Vicker’s hardness and compression test. MAed ODS-CrFeNi MEA, ODS-CoCrFeNi and ODS-CoCrFeNiMn HEA powders are of single face-centered cubic (FCC) crystal structure. After sintering, all three alloys consist of FCC matrix, body-centered cubic (BCC) structured Cr-rich phases, few Cr/Mn-rich oxides and high-density nanoscale oxides. Nanoscale oxides formed in the three alloys are all identified as Y4Zr3O12. In ODS-CrFeNi, the average size of oxides is 10 nm, and the number density in the BCC phase (3.2 ×1022/m3) is higher than that in FCC matrix (3.9 ×1021/m3). In ODS-CoCrFeNi and ODS-CoCrFeNiMn, the average size and number density of oxides increase to 19 nm, 20 nm and decrease to 2.3 × 1021/m3, 1.9 × 1021/m3, respectively. The amount of BCC phase decreases significantly in ODS-CoCrFeNi and ODS-CoCrFeNiMn HEAs compared with ODS-CrFeNi MEA. With the increasing principal element number, high entropy effect promotes more Y2O3 and Zr dissolve in the matrix during MA, but higher Y/Zr solubility and less precipitation of nanoscale oxides Y4Zr3O12 in the alloys during SPS/annealing. ODS-CrFeNi MEA exhibits the highest hardness of 475 HV and the highest compressive yield strength of 1531 MPa.

A comparative study of the elasto-plastic properties for ceramic nanocomposites filled by graphene or graphene oxide nanoplates

Abstract As nanoscale reinforcements, the graphene and graphene oxide nanoplates exhibit distinct mechanical and physical properties. The determination of the effective elasto-plastic behavior of nanoplate/ceramic nanocomposites and the different filling effects of graphene and graphene oxide nanoplate deserve systematic investigation. In this work, we intend to uncover how the graphene and graphene oxide nanoplates affect the macroscopic elasto-plastic characteristics of ceramic matrix nanocomposites and what differences in both nanoplates enhancements. A homogenization model is first utilized for determining the effective elastic parameters of nanoplate/ceramic composite with a perfect interface. Then the slightly weakened interface model is introduced to characterize the sliding effects of nanoplates in a ceramic matrix, and the effective elastic parameters of such nanoplates filled composites incorporating the interfacial sliding effects are explicitly formulated. Furthermore, a nonlinear micromechanics model is developed to investigate the macroscopic elastoplasticity and the yield behavior of graphene and graphene oxide nanoplate-filled ceramic nanocomposites subjected to confining pressure. The filling effects of the two kinds of nanoplates on the mechanical properties of such nanocomposite are comparatively examined. The calculated results demonstrate that types of the nanoplates and the imperfect interfaces between nanoplates and ceramic matrix have significant influences on the effective elasto-plastic behaviors of the nanoplate composites.

Simultaneous removal of nitrate, tetracycline, and Pb(II) by iron oxidizing strain Zoogloea sp. FY6: Performance and mechanism

Based on the prevalence of combined antibiotics and heavy metals contamination in the aquatic environment, this study utilized a microbial approach to achieve simultaneous removal of nitrate (NO3−-N), tetracycline (TTC), and Pb(II). Zoogloea sp. FY6 could achieve an optimal NO3−-N removal efficiency of 91.5% under C/N ratio of 2.0, at a pH of 6.3, and Fe(II) concentration of 20.23 mg L-1 based on response surface methodology. Additionally, strain FY6 was further found to achieve 89.9 and 81.7% removal of TTC and Pb(II) at 6 h under the optimal conditions. Finally, the results of Fluorescence excitation-emission matrix, X-ray diffraction, Fourier transform infrared spectrometer, and X-ray photoelectron spectroscopy further proved that the biologically formed nanoscale iron oxides and biological action jointly led to the removal of TTC and Pb(II). This study provided a theoretical basis for the application of microbially driven process to remove multi-pollutants in micro-polluted water bodies.

Manufacturing oxide-dispersion-strengthened steels using the advanced directed energy deposition process of high-speed laser cladding

In this work, we demonstrate the feasibility of manufacturing an iron-based oxide-dispersion-strengthened (ODS) PM2000 composite material with the chemical composition of Fe20Cr4.5Al0.5Ti + 0.5Y2O3 (in wt.%) via the advanced directed energy deposition (DED) process of high-speed laser cladding (HSLC). The characteristic high solidification rates of HSLC processes allow the successful dispersion of nano-scaled yttrium-based oxides in the ferritic stainless steel matrix. The effective suppression of nano-particle agglomeration during the melting stage, which is frequently observed in conventional DED processes of ODS materials, is reflected by smaller dispersoid sizes and corresponding higher hardness of manufactured specimen compared to DED-manufactured counterparts.

Acidity Controlled Desulfurization of Biogas by Using Iron (III) and Ferrosoferric (II, III) Oxide

Abstract Removal of hydrogen sulfide (H2S) from raw biogas is essential for feeding the refined gas with high methane (CH4) content in engines and combustion units. In small-scale farmhouses and power plants, a cheap, inexpensive, and facile desulfurization process is needed. Herein, the desulfurization process of biogas by treating with Fe2O3 and nanoscaled Ferrosoferric oxide (FeF) suspension is presented. The treatment process includes both the chemical reaction and physical adsorption phenomena. With variable pH and treatment duration, efficient desulfurization of the biogas was achieved. The optimum pH for H2S removal was 5 at which the removal efficiency was 97% for Fe2O3 solution and 95% for FeF solution. Respectively, CH4 content increased above 75%. The H2S-concentration dropped by 50 ppm from the initial value. The H2S content in the purified gas is thus reduced below the recommended limit for running internal combustion engines. We suggest some physicochemical elimination of the H2S fraction. The process might be feasible to utilize in small farmhouses and power units.

Insights into surface chemistry induced powder layer characteristic evolutions in additive manufacturing

Compared with large amount of work on the powder layer characteristics in powder-bed-based additive manufacturing (AM) under different operating conditions and powder properties, the significant effects of powder surface chemistry on the quality of the powder layer were less investigated. To further enhance people's insights in this aspect so as to obtain superior powder layer for subsequent process, Ti-6Al-4 V powders with different surface chemistries (e.g., the as received powder without any treatment, the moistened powder with surface H2O molecule, the exsiccated powder with grown nano-scaled oxides film) were firstly prepared, where the surface chemistry state of each powder was characterized and corresponding flowability and spreadability were measured in physical experiments. On this basis, systematic numerical investigations on the evolution of different surface chemistry induced powder layer characteristics during spreading were conducted. The results demonstrate that the surface moistened powder would deteriorate powder layer quality due to the strong cohesion effect between particles. However, the increase of the surface roughness on exsiccated powder could facilitate a greater deposition rate compared to that of the as-received powder during spreading, and therefore result in a powder layer with more pronounced apparent density. The mechanism lies in that high friction from the rough surface film could restrict the scattered motion behavior of sticky particles caused by the breakdown of cluster structure during the blade movement, and thus facilitate the most prominent deposition rate of this kind of particles during spreading. Nevertheless, the simultaneous increase of interactions within exsiccated powder also diminishes the boundary effect with blade and substrate, resulting in abnormal elevation of powder layer thickness, enlargement of internal pore volume, and depressed packing fraction correspondingly. Consequently, the powder with grown surface film is not ideal for printing, and the chemical reactions on powder that causes intensive film roughness should be prevented in powder storage and treatment process.

Preparation of graphene oxide coatings on textured Ti6Al4V by laser micromachining and electrophoretic deposition for improved biocompatibility

Introducing textures and coatings to titanium alloy implant is conducive to improving biocompatibility. In this paper, a two-step scheme comprising laser texturing process followed by electrophoretic deposition stage was investigated to fabricate micron-scale grooves covered with nano-scale graphene oxide (GO) coating precisely and controllably. The effect of multiple-pulse laser ablation on Ti6Al4V alloy (TC4) was analyzed and the correlation between laser parameters and ablation size was built. The normalized pulse overlap was adjusted by changing scanning speed and laser repetition frequency to fabricate well-structured and controllable micro-grooves. Electrophoretic deposition (EPD) of GO was conducted onto micro-grooved TC4 substrate to further improve the biocompatibility. The electrophoretic deposition process was conducted with different graphene oxide concentration and voltages at deposition times from 10 to 25 min. Thereafter, SEM, XRD and Raman test were carried out to analyze the quality and morphology of coatings. In addition, in vitro cellular evaluations and immunofluorescence staining had been used to test the biological properties of the micro-nano structure. The study shows that the micron-scale groove structure and nano-scale GO coating can remain the advantage of groove structure in cell contact guidance, as well as the advantage of GO in biocompatibility, which can promote cell adhesion and proliferation.

Anodic formation and properties of nanoscale oxide layers on silver–zinc alloys with different concentrations of non-equilibrium vacancies

Anodic formation and properties of nanoscale oxide layers on silver–zinc alloys with different concentrations of non-equilibrium vacancies

Simple Preparation of Multifunctional Luminescent Textile for Smart Packaging.

Linen has been a significant material for textile packaging. Thus, the application of the simple spray-coating method to coat linen fibers with a flame-retardant, antimicrobial, hydrophobic, and anticounterfeiting luminescent nanocomposite is an innovative technique. In this new approach, the ecologically benign room-temperature vulcanizing (RTV) silicone rubber was employed to immobilize the environmentally friendly Exolit AP 422 (Ex) and lanthanide-doped strontium aluminum oxide (RESAO) nanoscale particles onto the linen fibrous surface. Both morphological properties and elemental compositions of RESAO and treated fabrics were examined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), wavelength-dispersive X-ray fluorescence (WD-XRF), Fourier transform infrared (FTIR) spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). In the fire resistance test, the treated linen fabrics produced a char layer, giving them the property of self-extinguishing. Furthermore, the coated linen samples’ fire-retardant efficacy remained intact after 35 washing cycles. As the concentration of RESAO increased, so did the treated linen superhydrophobicity. Upon excitation at 366 nm, an emission band of 519 nm was generated from a colorless luminescent film deposited onto the linen surface. The coated linen displayed a luminescent activity by changing color from off-white beneath daylight to green beneath UV source, which was proved by CIE Lab parameters and photoluminescence spectral analysis. The photoluminescence effect was identified in the treated linen as reported by emission, excitation, and decay time spectral analysis. The comfort properties of coated linen fabrics were measured to assess their mechanical and comfort features. The treated linen exhibited excellent UV shielding and improved antimicrobial performance. The current simple strategy could be useful for large-scale production of multifunctional smart textiles such as packaging textiles.

Silica-Supported Nanoscale Hydrotalcite-Derived Oxides for C4 Chemicals from Ethanol Condensation

We demonstrated that the surface nature of nanoscale hydrotalcite-derived oxide (HTO) can be simply tailored through the addition of amorphous silica during the coprecipitation process of material preparation. The change in physical/chemical properties of the modified surface has been carefully scrutinized by a series of surface characterization techniques. The results showed that the HTO nanocomposite has molecular interactions with amorphous silica to form ternary Mg, Al, and Si interfaces, in accordance with enhancing chemically accessible aluminum (Al3+tetra) as acidic sites. Moreover, the silica-supported HTO (HTO/SiO2-X) could catalyze ethanol condensation to foster C4 chemicals at 250 °C through the flow reactor. HTO with a strong basic nature promoted 1-butanol production (66% selectivity), while HTO/SiO2-5 with more well-distributed acidic sites favored 1,3-butadiene production (43% selectivity). This difference in catalytic performance could be attributed to the redistribution of acidic and basic sites upon the newly formed ternary interfaces, which could facilitate the surface-mediated Meerwein–Ponndorf–Verley (MPV) reduction reaction due to the relatively high ethanol affinity.

Ultrahigh strength induced by multiple heterostructures in a FeMnCoCrN high-entropy alloy fabricated by powder metallurgy technique

Recently, high-entropy alloys (HEAs) in which the face-centered cubic (fcc) structure is dominant have attracted great attention due to their excellent ductility and good fracture toughness. However, the room-temperature yield strength of those alloys is usually low, which can not meet the demand of engineering applications. In addition, grain refinement in HEAs is limited, thus ultrahigh strength can not be achieved through grain boundary strengthening. In this study, a heavily N-doped (5 at.%) FeMnCoCr HEA with multiple heterostructures was prepared by the mechanical alloying (MA) method combined with spark plasma sintering (SPS). It consisted of recrystallized grains with the sizes ranging from submicron to micron and uniformly dispersed nano-scale nitrides and oxides. The N-doped alloy sintered at 900 °C exhibited a high compressive yield strength up to 1960 MPa at room temperature, which was ∼7.8 times stronger than that of the as-cast FeMnCoCr base alloy. In addition, under compression the soft and the hard domains within the inhomogeneous microstructures accommodated deformation with each other. This promoted continuous activation of dislocation slip and interactions between dislocations and stacking faults, leading to a satisfactory fracture strain of 21% and some work hardening ability for the alloy.

Effect of Al/Ti ratio on γ′ and oxide dispersion strengthening in Ni-based ODS superalloys

Oxide dispersion strengthened (ODS) Ni-based superalloys with high Al and Ti content (Ni–20Cr-xAl-yTi-0.6Y2O3-0.6Zr, x/y = ∼1, 1.8 and 16, named ST, SAT and SA alloy, respectively) and reference ODS alloy with low Al and Ti contents were produced by mechanical alloying and spark plasma sintering to investigate effect of Al/Ti atomic ratio on microstructure and Vickers hardness. The results showed that ST, SAT and SA alloys are strengthened by both γ′ phases and nanoscale oxides while the reference alloy is strengthened by only nanoscale oxides. The average size of γ′ increases but volume fraction decreases with decreasing Al/Ti atom ratio. The size and type of nanoscale oxides are different for the alloys with different Al/Ti ratios. The average size of nano-sized oxide is 10.7 nm for ST alloy, 14.7 nm for SAT and 10.2 nm for SA. Y4Zr3O12 and Y2Ti2O7 are identified in ST. Y4Zr3O12, Y2Ti2O7 and YAG(Y3Al5O12) are observed in SAT. Y4Zr3O12, YAM(Y4Al2O9), YAP (orthorhombic YAlO3) and YAH (hexagonal YAlO3) are confirmed in SA. Only Y4Zr3O12 is found in reference alloy. The hardness of ST, SAT and SA alloys is higher than reference alloy and increases with the decreasing Al/Ti ratio. The dependence of γ′ and nanoscale oxides on Al/Ti ratio and their contributions (oxide dispersion strengthening and γ′ precipitation strengthening) to mechanical properties are analyzed.

Forming‐Free Resistive Switching of Electrochemical Titanium Oxide Localized Nanostructures: Anodization, Chemical Composition, Nanoscale Size Effects, and Memristive Storage

AbstractElectrochemical anodization is a powerful method for the preparation of oxide thin films with controlled thickness, structure, and composition and proves as a promising approach to be applied to memristive devices. Here, experimental studies on titanium oxide nanoscale structures produced by local anodic oxidation and the influence of the thickness on the memristive properties are presented. Controllable preparation of forming‐free memristive cells with switching voltages less than 3 V are demonstrated. The chemical composition and oxidation state of the elements in the TiOxnanostructures are analyzed by means of X‐ray photoelectron spectroscopy, which reveals the formation of TiO2(458.4 eV), Ti2O3(456.6 eV), and TiO (454.8 eV). The increasing thickness of the devices from 4.5 ± 0.7 to 7.9 ± 0.3 nm leads to a decrease in the OFF to ON resistance ratio from 250 to 10.7, respectively. The mechanism of formation and resistive switching in the anodic devices is also discussed. The results can be applied to the design and development of technological processes for memristive structure manufacturing based on electrochemical oxidation.

Control of microstructure and hardness of ODS-CrFeNi MEAs by Y2O3/Zr addition

Oxide dispersion strengthened (ODS)-CrFeNi medium entropy alloys (MEAs) with different addition amounts of Y2O3/Zr were prepared by mechanical alloying (MA) and spark plasma sintering (SPS) to reveal the influence of Y2O3/Zr amounts on microstructure and mechanical properties. The microstructure was characterized by XRD, BSE, EBSD, HRTEM, and the micro-hardness was tested. The results show that ODS-CrFeNi MEA with 1 wt% Y2O3/Zr addition (1YZ alloy) mainly consists of face-centered cubic (FCC) matrix, body-centered cubic (BCC) phase and high-density nanoscale oxides Y4Zr3O12 while in ODS-CrFeNi MEA added 3 wt% Y2O3/Zr (3YZ alloy), additional [Ni, Zr] phase is formed except for FCC matrix, BCC phase and nanoscale Y4Zr3O12. The average size and number density of Y4Zr3O12 depend on the addition amount of Y2O3/Zr, which are 9.8 nm/3.9 × 1021/m3 and 24.6 nm/3.3 × 1021/m3 in 1YZ and 3YZ alloys, respectively. The average grain size of 1YZ and 3YZ alloy are 127 nm and 344 nm, respectively. The effective grain refinement in 1YZ alloy results in the higher hardness, which is 474 HV. The hardness of 3YZ alloy is 368 HV. The detailed strengthened mechanisms are discussed.

Deformation and cracking phenomena in cold sprayed 6061 Al alloy powders with nanoscale aluminum oxide films

This paper presents deformation and cracking phenomena associated with the cold spray of nanoscale surface oxide layers associated with the cold spray of 6061 Al alloy powders. The structure of the top surface oxide film was revealed via Focused Ion Beam (FIB), Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS). The observations show the oxide layer characteristics most likely matches crystalline γ-Al2O3. Phenomena associated with surface contacts, contact-induced elastic-plastic deformation, heating, and cracking are then studied using a combination of analytical models, Finite Element Analysis (FEA) and Molecular Dynamics (MD) simulations. MD simulations are also used to obtain estimates of oxide film young's moduli, strains to failure, and the fracture energies of oxide films. The results from the MD simulations and microscopy observations are incorporated into a bi-linear Johnson- Cook finite element simulations of cold spray contact-induced deformation and cracking due to the impact of aluminum powder particles with nanoscale oxide layers and similar substrates with nanoscale oxide layers. The powder impacts are shown to result in localized splat deformation and heating, along with the cracking of the oxide layers that expose fresh metallic surfaces to high temperature surface contacts (at temperatures above the recrystallization temperature for aluminum/6061 Al) that can give rise to bonding and mechanical interlocking. The implications of the results are then discussed for the design of cold spray processes for the fabrication and repair of 6061 Al structures.

Laser powder bed fusion additive manufacturing of oxide dispersion strengthened steel using gas atomized reaction synthesis powder

Mechanically alloyed Fe-based alloys with oxide dispersion strengthening have largely dropped out of the marketplace due to high cost related to problems with complex and unreliable processing. Nevertheless, the desirable properties of oxide dispersion strengthened (ODS) steels have motivated research on alternate processing routes aimed at improving processing simplicity and reliability. Powders produced by gas atomization reaction synthesis (GARS) consist of stable Fe-Y intermetallic phases and a Cr surface oxide layer that acts as a chemical reservoir during solid-state processing and heat treatment to form a high density of nano-scale oxides. This research explores the use of Fe GARS powders, with 15 wt% Cr with micro-alloyed additions of 0.15 wt% Y and 0.10% Ti, in laser powder bed fusion (LPBF) additive manufacturing (AM), and evaluates the effectiveness of oxide dispersoid formation in the liquid melt pool. Additional oxygen was introduced by varying the LPBF chamber atmospheres using Ar, Ar + 1 wt% O, Ar + 5 wt% O, and air. Characterization of LPBF consolidated solids demonstrated the formation of a high density of nano-scale Y-Ti oxides in the build microstructures from the GARS precursor powders.

Assessment of dental implant surface stability at the nanoscale level

ObjectivesTo study the oxide layer stability of certified dental implants of system "P", made based on TiO2 alloy with carbon coating. To perform a comparative statistical analysis of the obtained data with the available data for the dental implants of systems "A" and "B". MethodsX-ray microtomography and X-ray fluorescence analysis were used to study soft tissue biopsy specimens. Supernatants were studied by dynamic light scattering and transmission electron microscopy when simulating free emission of nanoscale metal oxide particles from the surface of dental implants as well as when simulating physical loading. A comparative analysis of three parameters of nanoscale particles was performed by statistical data analysis. The surface of the "P" system dental implant with surface treatment was analyzed by scanning electron microscopy. ResultsBoth free emission of nanoscale oxide layer particles and yield of nano- and microscale particles during simulation of physical load were confirmed. Statistically significant differences were noted in a comparative analysis of the size and frequency of occurrence of these particles in the supernatants obtained from the surfaces of three dental implant systems. The elemental composition of the particles and the composition and structure of the "P" system dental implants themselves were analyzed. SignificanceThe developed method of dynamic light scattering can be used to compare the stability of the oxide layer of standardized medical products manufactured on the basis of the TiO2 alloy.

Facile ultrasonic aided green reduction of graphene oxide by Doum palm fruit

This work describes a novel, facile, green, and one-step sonochemical method for reducing graphene oxide (GO) using Doum palm fruit. The successful transformation of GO into reduced graphene oxide (RGO) is confirmed via several techniques. FTIR confirmed the removal of most oxygen functional groups from GO and conjugation between Doum and derived reduced graphene oxide (GRGO). From XRD, the GO sharp peak was disappeared upon reduction and replaced by a wide broad peak. X-ray photoelectron spectroscopy (XPS) studies revealed an increase of the (C/O) ratio in GRGO compared to GO. The crumpled morphology of GO occurs upon reduction noticed from HRTEM. Corrugation and cracks in GO sheets are observed after the reduction process, FESEM revealed. The thermal stability of GRGO is higher than that of GO. These findings illustrate that this method is promising for the mass production biosynthesizing nanoscale oxides conjugated to reduced GO for medicinal and biological applications.