Electrophoretic Deposition Method Research Articles

Evaluation of tribological and biological properties of Ti6Al4V coated with Si3N4/ND nanoparticles for orthopedic applications: a comprehensive analysis.

In this study, the biocompatibility and tribological properties of Ti6Al4V coated with Silicon Nitride (Si3N4)/Nanodiamond (ND) using the electrophoretic deposition (EPD) method were investigated. Suspensions of various aqueous and alcoholic solutions were prepared in the presence of CTAB and SDS dispersers. The most stable suspension system for the electrophoresis process was selected (aqueous media/ SDS disperser). Four different voltages (20, 30, 40, and 50 V) were applied to study the effect of voltage on the coating property. One could find that processing with 40 V obtained the best coating. The nano-composite coating was characterized using scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), mapping analysis, and X-ray diffraction (XRD) after the coating process. The samples were then subjected to two nanoindentation and nano-scratching tests to evaluate their tribological properties. Biocompatibility was assessed in an ex vivo environment using two cell culture tests to evaluate survival and cellular adhesion. The results showed that the hardness and modulus elasticity of the coated sample increased from 85 to 124 GPa and 1.14 to 3.55 GPa, respectively, compared to the non-coated sample. Additionally, the MTT test results indicated that cellular survival and proliferation of MG63 cells increased from 86% for the non-coated sample to 92% for the Ti6Al4V/Si3N4 /ND sample. These findings have implications for orthopedic implant applications.

Study of Nanohydroxyapatite Coatings Prepared by the Electrophoretic Deposition Method at Various Voltage and Time Parameters.

The aim of the work is to compare the properties of nanohydroxyapatite coatings obtained using the electrophoretic deposition method (EDP) at 10 V, 20 V, and 30 V, and with deposit times of 2 and 5 min. The primary sedimentation was used to minimize the risk of the formation of particle agglomerates on the sample surface. Evaluation of the coating was performed by using a Scanning Electron Microscope (SEM), Energy-Dispersive Spectroscopy (EDS), Atomic Force Microscopy (AFM), optical profilometer, drop shape analyzer, and a nanoscratch tester. All of the coatings are homogeneous without any agglomerates. When low voltage (10 V) was used, the coatings were uniform and continuous regardless of the deposition time. The increase in voltage resulted in the formation of cracks in the coatings. The wettability test shows the hydrophilic behavior of the coatings and the mean contact angle values are in the range of 20-37°. The coatings showed excellent adhesion to the substrate. The application of a maximum force of 400 mN did not cause delamination in most coatings. It is concluded that the optimal coating for orthopedic implants (such as hip joint implants, knee joint implants or facial elements) is obtained at 10 V and 5 min because of its homogeneity, and a contact angle that promotes osseointegration and great adhesion to the substrate.

Exploring the improving role of MWCNTs on the electrochemical behavior of electrophoretically prepared Ti/nanoZnO metal oxide electrode: A comparative study

In recent years, a growing amount of attention has been paid to the investigation and modification of metal oxide anodes as a critical parameter in electrochemical removal. In this way, this research attempts to bring out an effective comparison between modified Ti/nanoZnO electrode by multi-walled carbon nanotubes (MWCNTs) and base Ti/nanoZnO electrode. The electrophoretic deposition (EPD) method was used to prepare electrodes. The morphological and chemical composition of the surface for both electrodes were obtained by using characterization tests including field emission scanning electron microscope - energy dispersive spectrometer (FESEM-EDS), elemental mapping, and X-ray diffraction (XRD). Furthermore, the electrochemical behavior of Ti/nanoZnO as well as Ti/nanoZnO-MWCNTs electrodes were compared using linear sweep voltammetry (LSV), chronopotentiometry (CP), and chronoamperometry (CA) analysis. In the final step, the chemical oxygen demand (COD) removal in addition to the decolorization rate of a dyes mixture was used to evaluate the electrochemical performance in the same conditions. Presented results in this study showed the importance of metal oxide anode modification by improved deposited coating properties of Ti/nanoZnO-MWCNTs electrode compared with base ZnO electrode.

Functionalized High Entropy Alloys with ZIF-8 and LDH Nanolayers for Next-Generation Drug Eluting Medical Implants

In this study, high entropy alloys (HEA) were fabricated by mixing Ni, Co, Cr, Fe, and Mn powders and then subjected to spark plasma sintering (SPS). Samples were coated by Al-Zn-layered double hydroxide (LDH) nanoparticles (NPs), SiO2 coated Al-Zn-layered double hydroxide NPs (LDH@Sio2), and zeolite imidazole framework (ZIF-8 NPs) using the electrophoretic deposition (EPD) method. To enhance immune response, antiviral effects, and iron uptake, ascorbic acid was intercalated within LDHs and ZIF-8 NPs layers via the ion-exchange method. Microstructural properties were examined using the X-ray diffraction method (XRD), optical microscopy, and scanning electron microscopy (SEM). The corrosion behavior of the specimens was investigated by a potentiodynamic polarization scan (PDS). A UV-visible evaluation test was conducted to assess drug release from the coated samples. SEM images demonstrated a homogenous microstructural coating, and XRD results confirmed that successful incorporation of vitamin C into LDH NPs, as indicated by an increase in layer distance from 7.36 to 7.46Å. UV-visible studies revealed that LDH@SiO2 NPs exhibited a vitamin C release rate exceeding 5% compared to other coatings. Cell adhesion and proliferation assays using the MTT assay further confirmed the biocompatibility of the samples and their appropriate biological response to MG63 cells.

Effect of hydroxyapatite coating thickness on inflammation and osseointegration of Ti–29Nb–13Ta-4.6Zr (TNTZ) implants

The study investigates the effect of Hydroxyapatite (HA) coating thickness on the inflammation and osseointegration properties of Ti–29Nb–13Ta-4.6Zr (TNTZ) implants for orthopedic implant applications. TNTZ screws were used as based samples, and the HA coating was deposited using an Electrophoretic Deposition (EPD) method to achieve various coating thickness. The thin (50–70 μm), medium (70–90 μm), and thick (90–110 μm) coating thicknesses were obtained by applying different voltage and time exposure during the EPD process, while the uncoated screw was used as the control sample. The screws were implanted into the right tibia of male Rattus norvegicus Wistar rats, and the animals were kept in cages and provide with ad libitum food for two weeks. After termination of the test animals, blood samples were collected to measure levels of Tumor Necrosis Factor-α (TNF-α) using an ELISA method, and a removal torque test was performed on the implanted screws. Additionally, tibial bone tissue around the implant area was collected for histopathology analysis. The result of the study indicate that HA coating thickness has an effect on TNF-α concentration, removal torque value, and new bone growth. The optimal thickness of the HA layer was found to be in the medium range (70–90 μm), resulting in low inflammation levels, relatively high osseointegration rates, and optimal new bone tissue growth. These finding are expected to be applicable in future orthopedic implant applications.

Design, Construction and Programming of a Low-Cost Pulsed High-Voltage Direct Current Power Supply for the Electrophoretic Deposition of Silicon Carbide Mixed with Graphite and/or Alumina for Thermoelectric Applications

This document describes a proprietary design, construction, programming and testing of a low-cost pulsed high-voltage direct current (HVDC) power supply with an output of 430 V and power of 25 W. The design obtained allows costs to be reduced compared to commercial ones, highlighting that the manufacturing of this HVDC is easy to replicate. To demonstrate the operation of the pulsed power supply prototype, coatings of silicon carbide (SiC) and SiC mixed with graphite (C) and/or alumina (Al2O3) were made using the electrophoretic deposition (EPD) method. After processing, samples underwent a heat treatment at 500 °C to evaluate their thermoelectric (TE) efficiency. The samples were analysed via X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, Seebeck coefficient, electrical conductivity and thermal conductivity. The Seebeck coefficient, electrical conductivity and thermal conductivity were measured in a temperature range of 100–500 °C in a nitrogen (N2) atmosphere. The electrical conductivity of the SiC 6C-4Al sample was 0.65 S/cm at 500 °C, while the maximum Seebeck coefficient was 2500 μV/K of the SiC 6C-4Al sample at 200 °C. The thermal conductivity of SiC 6C-4Al was in the range of 0.35–0.37 W/m·K, which was much lower than the SiC sample free of alumina and graphite in the same measured temperature range. In conclusion, the SiC 6C-4Al sample presented the highest figure of merit with a ZT ≈ 0.01.

A Flexible One‐dimensional Woven Supercapacitor for Low‐power Smart Electronic Textiles

Flexible energy storage devices are attracting a great attention nowadays in the rapidly growing area of implantable/wearable electronics. This bloom has generated great demands on flexible wire‐shaped supercapacitors (WSC) as power sources in wearable electronic systems that can offer tunable sizes, shapes, and versatile designs. Herein, a flexible WSC is fabricated using MgMn2O4 nanofibers (MMO‐NFs) over a flexible carbon yarn substrate via the electrophoretic deposition method in the first report. The binder‐free deposition of highly porous and one‐dimensionally aligned MMO‐NFs over carbon yarn offers excellent ionic/charge transport into the fabricated device. The assembled WSC device at 0.1 mA/cm current rate shows capacitances of 386 mF/cm2 and 45.5 mF/cm. A capacitance retention of 88% for a WSC device after 10,000 cycles indicates its good cyclability. Further, the WSC exhibits good flexibility, retaining 94% of capacitance at 0.5 mA/cm after 2000 bending cycles. Furthermore, the flexible WSC device shows power and energy density of 744 μW/cm and 14.2 μWh/cm, respectively. Additionally, WSC devices demonstrate their practical energy storage capabilities in a video that shows three similar devices being knitted into a wearable glove and glowing a red light‐emitting diode (LED) for more than five minutes in various bending positions.

CdSe nanostructured thin film by electrophoretic deposition for quantum dots sensitized solar cell.

Cadmium selenide (CdSe) quantum dots (QDs) with different size, 2.5 and 3.2 nm, were successfully deposited on mesoporous titanium dioxide (TiO2) (Degussa-P25) nanostructures by electrophoretic deposition method (EPD) at the applied voltage 100 V for 120 s deposition time. In this study, the morphology of CdSe films deposited by EPD and the performance of the film when assembled into a solar cell were investigated. From the field emission scanning electron microscopy cross-section, the thickness of the CdSe nanoparticles with size 2.5 nm films were 3.4 and 3.0μm for CdSe 3.2 nm nanoparticles film. The structure of 2.5 nm is denser than compare of 3.2 nm CdSe nanoparticles. From UV visible spectroscopy, the band gap calculated for 2.5 nm CdSe nanoparticles is 2.28 eV and for 3.2 nm is 2.12 eV. Photovoltaic characterization was performed under an illumination of 100 mW cm-2. A photovoltaic conversion efficiency of 1.81% was obtained for 2.5 nm CdSe and 2.1% was obtained for 3.2 nm CdSe nanoparticles. This result shows that the photovoltaic efficiency is dependent on CdSe nanoparticle size.

Enhanced CMAS and hot corrosion degradation of YSZ thermal barrier coating with nano powders

Thermal barrier coatings are used to protect hot section parts of gas turbine engines. These coatings are subject to corrosion due to impurity elements in the fuel and dust absorbed from the atmosphere into the engine. The rough and porous surface nature of plasma-sprayed coatings facilitates the penetration of these factors into the coating. Coatings are damaged prematurely as a result of corrosion. In this study, nano-structure YSZ, YSZ + Al2O3, YSZ + TiO2, and YSZ + Al2O3 + TiO2 coatings were deposited on plasma sprayed YSZ coating by electrophoretic deposition method. Hot corrosion and CMAS resistance were investigated. The coatings were characterized by SEM, XRD, AFM, and microhardness before corrosion tests. The changes in the coatings after corrosion tests were characterized by SEM and XRD. The penetration behavior of corrosive factors was examined by elemental mapping with EDS. Nanostructure coatings deposited on APS YSZ made the surfaces of as-sprayed coatings more stable. The ability of these nanolayers to prevent pure penetration into coatings during hot corrosion and CMAS is limited. However, the Al2O3 + TiO2-doped nanostructure YSZ reduced the bond-layer oxidation. In addition, the addition of Al2O3 + TiO2 to the EPD deposited layer also reduced the tetragonal-monoclinic phase transformation that occurred in YSZ as a result of corrosion. Al2O3 and TiO2 additives alone are not effective in improving the corrosion behavior of coatings. Nanostructured coatings deposited with the EPD technique can help protect plasma-sprayed thermal barrier coatings against corrosion.

Suspension and process parameters selection for electrophoretic deposition of Mn–Co spinel coating on steel interconnects

Metallic interconnect coatings, consisting of MnCo2O4 spinel, were effectively applied to Crofer 22 APU using the electrophoretic deposition (EPD) method in both H2O: ethanol and pure ethanol solvents. The primary goal of this method was to prevent chromium migration, minimize evaporation, and control the oxidation rate. The study aimed to assess the quality, adhesion, and thickness of the Mn–Co coating, with the objective of achieving a consistent and uniform layer. The results indicated a preference for pure ethanol solvent over H2O: ethanol (40:60 %Vol) for Mn–Co particles. Furthermore, the agglomeration of Mn–Co particles was notably lower (approximately 7 times) in ethanol compared to H2O: ethanol. The morphology and surface roughness of the sintered Mn–Co coating on the alloy were examined using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). A uniform and dense coating was successfully attained using pure ethanol solvent at a solid concentration of 10 g/L, with 0.5 g/L of iodine serving as a disperser. The deposition process, carried out at a voltage of 30V for 20 s, resulted in a coating with a thickness of 7.4 ± 0.3 μm and a surface roughness of 0.75 ± 0.5 μm.

Eco-Friendly Electrophoretic Deposition of Fluorescent Nanocomposite Films in an Aqueous Dispersion of Hydrophilized Core/Shell CuInS2/ZnS Quantum Dots for Optoelectronic Applications.

Low-toxic and efficient fluorescent core-shell CuInS2/ZnS (CIS/ZnS) quantum dots (QDs) are good candidates for optoelectronic device applications. They are synthesized in a hydrophobic environment, while large amounts of organic solvents used in the preparation of fluorescent films have significant problems on environmental load and human health. CIS/ZnS QDs hydrophilized by adsorbing 3-mercaptopropionic acid on their surfaces can be used in the aqueous film fabrication process. In this work, the aqueous electrophoretic deposition (EPD) of the hydrophilized QDs with silicone-modified acrylic resin nanoparticles was performed to fabricate fluorescent nanocomposite films. The hydrophilized QDs and resin nanoparticles were simultaneously dispersed in basic aqueous solutions due to electrostatic repulsion resulting from their negatively charged surfaces. Transparent films were obtained on a transparent conductive substrate at the anode side by the EPD. They showed yellow fluorescence of the QDs. The thickness increased with increasing the deposition time; however, hemispherical holes attributed to oxygen gas generated by water electrolysis were observed at the longer time. The electron microscopy revealed that the films were densely and homogeneously deposited. The QDs were dispersed around the resin nanoparticles without aggregation. The fluorescence (FL) quantum yield was 43%. The optical absorption peak and FL intensity of the QDs increased accompanied by the film growth. The nanocomposite film showed good heat resistance at 80-120 °C for 5 h; therefore, the prepared films have feasibility in white light-emitting diode (LED) applications. A lightening device structured with the obtained EPD film placed on a blue LED successfully emitted white light. In addition, the flexibility of the nanocomposite film was demonstrated. The aqueous EPD method would be one of the suitable methods for the industrial production of fluorescent QD films. This technique can be applied to other hydrophilic fluorescent QDs with charged surfaces. Realization of various fluorescent QD films would expand the application possibilities.

Functionalization of the NiTi Shape Memory Alloy Surface through Innovative Hydroxyapatite/Ag-TiO2 Hybrid Coatings.

The objective of this research was to develop a surface modification for the NiTi shape memory alloy, thereby enabling its long-term application in implant medicine. This was achieved through the creation of innovative multifunctional hybrid layers comprising a nanometric molecular system of silver-rutile (Ag-TiO2), known for its antibacterial properties, in conjunction with bioactive submicro- and nanosized hydroxyapatite (HAp). The multifunctional, continuous, crack-free coatings were produced using the electrophoretic deposition method (EPD) at 20 V/1 min. Structural and morphological analyses through Raman spectrometry and scanning electron microscopy (SEM) provided comprehensive insights into the obtained coating. The silver within the layer existed in the form of nanometric silver carbonates (Ag2CO3) and metallic nanosilver. Based on DTA/TG results, dilatometric measurements, and high-temperature microscopy, the heat treatment temperature for the deposited layers was set at 800 °C for 2 h. The procedures applied resulted in the creation of a new generation of materials with a distinct structure compared with the initial nanopowders. The resulting composite layer, measuring 2 μm in thickness, comprised hydroxyapatite (HAp), apatite carbonate (CHAp), metallic silver, silver oxides, Ag@C, and rutile exhibiting a defective structure. This structural characteristic contributes significantly to its heightened activity, influencing both bioactivity and biocompatibility properties.

Research of chitosan coatings deposited by electrophoretic deposition method at various voltage and time parameters

The aim of this research is to estimate the electrophoretic deposition main parameters, such as voltage and time duration, that will provide optimal characteristics of the surface layer. Chitosan coatings were synthesized on biomedical Ti13Zr13Nb alloys at 20 V and 30 V and with deposit times of 2min, 5 min, 10 min, and 15 min. Evaluation of the coating was performed by using Scanning Electron Microscope (SEM), Energy-Dispersive Spectroscopy (EDS), Laser-Induced Breakdown Spectroscopy (LIBS), Atomic Force Microscopy (AFM), drop shape analyzer and nanoscratch tester. Homogeneous and continuous coatings are obtained for 2 min and 5 min, regardless of the voltage. Defects in form of bubbles are observed only for 20 V during 10 min, 20 V during 15 min, and 30 V during 10 min. All of the coatings show hydrophilic behavior. The critical loads for delamination range are between 100 mN and 300 mN. It is concluded, that the optimal coating for orthopedic implants is obtained at 20 V, 5 min, because of homogeneity, a contact angle supporting osseointegration and the best adhesion. The optimal one for implant in contact with blood is obtained at 20 V, 2 min, because it is homogenous and shows the lowest hydrophilicity, which should limit the thrombogenicity of the coating.

Fabrication of three dimensional graphene/carbon nanotube/copper foam field emitter by electrophoretic deposition and its emission properties

In this paper, the graphene/carbon nanotubes/copper foam (GR/CNTs/CuF) three-dimensional field emitters were prepared by electrophoretic deposition (EPD). For comparison, the graphene/copper foam (GR/CuF) and carbon nanotubes copper foam (CNTs/CuF) field emitters were also prepared by the same way and characterized by the several different methods. The turn on electrical field (Eon) of composite materials of GR/CNTs/CuF was obtained to be 0.85 V/μm. Threshold electric field (Eth) is 1.52 V/μm. The composite of GR/CNTs/CuF have a large contact area, a lower volume resistance and lower contact resistance, which is more easy to electron transport. The root of the CNTs or the fold tip of GR is fixed in the interlaced composite, and the tip or fold forms a stable micro tip emission structure, which enhanced the field strength factor. The field emission performances are significantly better than that of individual GR/CuF or CNTs/CuF field emitter. The GR/CNTs/CuF as 3D field emitters were prepared by EPD method with low cost and easy manipulation, which provided a good way for a large-scale preparation of composite field emitters.

Reinforcement of carbon fibers: γ-irradiation induced microporous modulation and surface defect repairing with graphene quantum dots

Due to the presence of numerous defects both internally and on the surface, carbon fiber exhibits mechanical properties far below theoretical predictions. Finding a rapid and effective method for reinforcing the matrix remains a challenge. To address this, we have conducted structural reinforcement of carbon fiber by improving the orientation of internal micropores and eliminating surface defects. On the one hand, we subjected the carbon fiber to a dose of 100 kGy of gamma-ray irradiation in the air. After testing, the mechanical properties of the carbon fiber improved by 5.59%. Analysis using techniques such as small-angle x-ray scattering revealed that gamma rays can slightly alter the orientation of the fiber’s internal micropores and enhance graphitization to some extent. On the other hand, we introduced graphene quantum dots (GQDs) onto the surface of the carbon fiber using electrostatic spraying and electrophoretic deposition techniques to fill the defect sites. Compared to untreated carbon fiber, the mechanical properties improved by 10.65% and 9.40% when GQDs were grafted using electrophoretic deposition and electrostatic spraying methods, respectively. This improvement can be attributed to the adsorption of GQDs on the surface of the carbon fiber, which disperses stress during tensile loading and delays fracture. Finally, grafting of GQDs onto the surface of gamma-irradiated carbon fibers by electrophoresis improved the mechanical properties of the carbon fibers by 15.53% compared to unmodified carbon fibers. This work provides a more comprehensive perspective for repairing carbon fiber structures.

Mechanical properties of SiCf/SiC composites with h‐BN interphase formed by the electrophoretic deposition method

AbstractSilicon carbide fiber–reinforced silicon carbide (SiCf/SiC) composites have been expected to be used as next‐generation heat resistant structural materials with high reliability. The fiber/matrix interface for SiCf/SiC composites plays an important role for toughening and strengthening, and it is important to form the optimal interphase for SiCf/SiC composites. In this study, hexagonal‐boron nitride (h‐BN), which shows better oxidation resistance than carbon, was selected as the interphase for SiCf/SiC composites, and h‐BN coating was formed on low‐conductive SiC fibers by the electrophoretic deposition (EPD) method using flaked h‐BN suspension prepared by wet‐jet milling. Unidirectional SiCf/SiC composites with the BN interphase formed by the EPD method were prepared by polymer impregnation and pyrolysis (PIP) method, and their mechanical properties were evaluated. The uniform h‐BN interphase was successfully formed on the low‐conductive SiC fibers by EPD when thin polypyrrole (Ppy) coating, that is, conductive polymer, was formed on the SiC fibers. The h‐BN coating became denser by heat‐treatment at 1000°C, and the h‐BN coating deposited tightly on the SiC fibers was confirmed. It was demonstrated that the SiCf/SiC composites with the uniform and relatively dense h‐BN interphase formed by EPD using flaked h‐BN particles exhibited pseudo‐ductile fracture behavior with large amount of fiber pullout and higher fracture energy.

Cu- and Ce-doped MnCo2O4 spinel coatings on ferrite interconnects by electrophoretic deposition

MnCo2O4 spinel coating is considered as one of the most promising protective coatings on the surface of ferritic stainless steel interconnects in solid oxide fuel cells (SOFCs). And the doping of metallic elements and active rare earth elements may further improve the electrical conductivity and antioxidant properties of spinel coatings. In this work we firstly prepare the Cu-doped and Ce-doped MnCo2O4 spinel coatings (abbreviated as MCCu, MCCe) on the surface of SUS430 substrate by Sol-Gel and electrophoretic deposition methods. The optimal doped ratio of Cu and Ce based on the results of oxidized mass gain and area-specific resistance (ASR) tests are determined respectively. Then we deposit Cu-Ce co-doped MnCo2O4 spinel coatings (abbreviated as MCCuCe) accordingly. The successful deposition of the target modified spinel coating on the substrate surface is confirmed using SEM-EDS, XRD, XPS characterization. The performance test results of the MCCuCe coating on the SUS430 surface show that the mass gain after 500 h oxidation at 800 °C in air is 1.3564 × 10−3 mg cm−2, and the ASR at 800 °C after 500 h oxidation is 9.80mΩ cm2, which is much lower than those of the bare SUS430 substrate and the substrate with deposited MnCo2O4 spinel coating. And the MCCuCe protective coating plays a better role in preventing the diffusion of Cr from the substrate. Further analysis prove that the doping Cu mainly contributes to the electrical conductivity and adhesion to the substrate while the doping Ce mainly improve the anti-oxidation and Cr diffusion resistance. This work determines the optimal doped ratio of Cu and Ce and provides a simple way to prepare the Cu-Ce co-doped MnCo2O4 spinel coatings on the ferritic interconnects, which effectively improve comprehensive performances of MnCo2O4 spinel coatings and helps to accelerate the industrial application of SUS430 ferrite in the SOFCs.

EPD method for thin films on solar cells

Electrophoretic deposition (EPD) deposits thin films, with simple yet efficient deposition of nanomaterial. This work deposited photoanodes of zinc oxide on fluoride-doped tin oxide (FTO) decorated with tin chloride, changing the applied tension between 30 V, 40 V, and 50 V. Afterwards, the sandwiched photoanodes (Sn/ZnO/FTO) were assembled on dye solar cells, for photovoltaic tests. The results demonstrated a better short current density for the 30 V (10 % Sn/ZnO), at about 6.32 mA/cm2, and incident photocurrent efficiency (IPCE) of 12.5 %.

Ag2O@UiO-66 new thin film as p-n heterojunction: permanent photoreduction of hexavalent Cr.

The new nanosphere Ag2O@UiO-66 thin-film was synthesized on a stainless steel mesh surface via an electrophoretic deposition method, and is used as an effective and low-cost photocatalyst using visible light. The synthesized nanocomposite was used to perform photo-reduction of Cr(vi) ions under white light irradiation. The best removal rate (72% after 15 minutes) was obtained by the film with 0.034 grams of deposited composite having relative percentages of Ag2O : UiO-66 of 70 : 30. The interesting obtained results confirm that the p-n heterojunction of the composite is the main cause of the desired charge separation and the photoreduction speed increase. In the following, the resulting compounds were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmittance electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy diffraction X-ray spectroscopy (EDAX) and the Brunauer, Emmett, and Teller (BET) method. Scavenging studies performed in the presence of familiar scavengers confirmed that superoxide radicals (˙O2-) and dissolved oxygen gas have a significant role in the photocatalytic reduction process.

Ti3C2Tx@polyaniline/epoxy coating based on cathodic electrophoretic deposition with effective corrosion inhibition effect for corrosion protection on P110 steel

Polyaniline-coated Ti3C2Tx particles (TPi) endowed the electrophoretic deposited epoxy coating with efficient physical shielding and corrosion inhibition capacities to improve the corrosion protection ability. Ti3C2Tx of few/single layers was prepared and TPi particles were synthesized by in-situ polymerization of polyaniline on Ti3C2Tx surface. Characterization results indicated the successful synthesis of TPi material. TPi/epoxy coating was prepared on P110 steel sheet through cathodic electrophoretic deposition method, and the protection ability was tested by electrochemical impedance spectroscopy (EIS) and saline immersion test. EIS results of the complete coating showed that impedance modulus at low frequency (0.01 Hz) of TP7 coating was 3.92 × 108 Ω cm2 after soaking for 20 d, which was higher than 2.82 × 106 Ω cm2 of neat epoxy coating (NEP), indicating better protection performance. The results of impedance spectrum of scratched coating showed that TP7 coating had obvious corrosion inhibition effect, which was attributed to the passivation effect of polyaniline to promote the conversion of loose corrosion products into dense layers. This research provided a new approach to apply Ti3C2Tx into the electrophoretic deposited epoxy coating with corrosion inhibition effect.