Triboelectric nanogenerator based on electrodeposited Ag octahedral nano-assemblies

The tremendous potential of triboelectric generators-TENGs for converting mechanical energy into electrical energy places them as one of the most promising energy harvesting technologies. In this work, the fabrication of enhanced performance TENGs using Ag octahedron nano-assemblies on ITO as electrodes significantly increases the electric charge collection of the induced tribocharges. Thereby, nanostructured electrical contacts coated with Ag macroscale nano-assemblies with octahedral features were obtained by the electrodeposition technique on flexible PET/ITO substrates. Consequently, the nanostructured triboelectric generator-TENG exhibited 65 times more maximum output power, and almost 10 times more open circuit output voltage than that of a TENG with non-nanostructured contacts passing from μW to m W capabilities, which was attributed to the increment of intrinsic interface states due to a higher effective contact area in the former. Likewise, output performances of TENGs also displayed an asymptotic behavior on the output voltage as the operating frequency of the mechanical oscillations increased, which is attributed to a decrement in the internal impedance of the device with frequency. Furthermore, it is shown that the resulting electrical output power can successfully drive low power consumption electronic devices. On that account, the present research establishes a promising platform which contributes in an original way to the development of the TENGs technology.

Effects of laser energy on the surface quality and properties of electrodeposited zinc-nickel-molybdenum coatings

As a substitute for toxic cadmium coatings in the aerospace industry,zinc-nickel coatings have excellent application prospects,and their properties can be improved by adding molybdenum.In this study,laser-assisted electrodeposition is used to improve the surface quality and properties of Zn–Ni–Mo coatings,with investigation of how laser energy in the range of 0–21.1μJ affects their element content,surface morphology,crystal phase,microhardness,residual internal stress,and corrosion resistance.The laser irradiation accelerates the electrodeposition,refines the grain size,improves the hydrogen adsorption,and reduces the residual tensile stress,and a laser energy of 15.4μJ gives the highest Ni and Mo contents and the lowest Zn content,as well as the optimum surface morphology,microhardness,residual internal stress,and corrosion resistance of the coating.

Electrodeposited 3D hierarchical NiFe microflowers assembled from nanosheets robust for the selective electrooxidation of furfuryl alcohol

A robust and green strategy for the selective upgrading of biomass-derived platform chemicals towards highly valuable products is important for the sustainable development.Herein,the efficient electrocatalytic oxidation of biomass-derived furfuryl alcohol(FFA)into furoic acid(FurAc)catalyzed by the electrodeposited non-precious NiFe microflowers was successfully reached under the low temperature and ambient pressure.The 3D hierarchical NiFe microflowers assembled from ultrathin nanosheets were controllably synthesized by the electrodeposition method and uniformly grown on carbon fiber paper(CFP).Electrochemical analysis confirmed that NiFe nanosheets more preferred in the selective oxidation of FFA(FFAOR)than oxygen evolution reaction(OER).The linear sweep voltammetry(LSV)in FFAOR displayed a clear decrease towards lower potential,resulting in 30 mV reduction of overpotential at 20 mA cm^(-2) compared with that of OER.The optimal catalyst Ni_(1)Fe_(2) nanosheets exhibited the highest selectivity of FurAc(94.0%)and 81.4%conversion of FFA within 3 h.Besides,the influence of various reaction parameters on FFAOR was then explored in details.After that,the reaction pathway was investigated and rationally proposed.The outstanding performance for FFAOR can be ascribed to the unique structure of 3D flower-like NiFe nanosheets and oxygen vacancies,resulting in large exposure of active sites,faster electron transfer and enhanced adsorption of reactants.Our findings highlight a facile and convenient mean with a promising green future,which is promising for processing of various biomass-derived platform chemicals into value-added products.

Developing high photocatalytic antibacterial Zn electrodeposited coatings through Schottky junction with Fe3+-doped alkalized g-C_(3)N_(4) photocatalysts

Pure Zn coatings easily lose their protective performance after biofouling because they have no antibacterial effect under visible light.In this study,we fabricate a new antibacterial Zn composite coating using electrodeposition to couple Fe3+-doped alkalized g-C_(3)N_(4)(AKCN-Fe)into an existing Zn coating and show that the AKCN-Fe enhances antibacterial property of the Zn coating under visible light.We attribute this enhancement to the high photocatalytic performance,high loading content,and good dispersion of AKCN-Fe.In addition,the photocatalytic antibacterial mechanism of the composite coating is supported by scavenger experiments and electron paramagnetic resonance(EPR)measurements,suggesting that superoxide(·O_(2)^(-))and hydroxyl radical(·OH)play main and secondary roles,respectively.

Investigation of Formation Process of the Chrome-free Passivation Film of Electrodeposited Zinc

The feasibility was investigated to substitute chrome-free passivation treatment of electrodeposited zinc in a titanium bath for chromate passivation treatment. The formation mechanism of the chrome-free passivation film was further analyzed. The surface mor- phologies and the elemental compositions of the treated samples with varied immersion times were observed by scanning electron mi- croscopy （SEM） and determined by energy dispersion spectrometry （EDS）, respectively. The electrode potential of the sample surface was recorded in the film formation process. The changes of the electrode potential are in accordance with that of SEM and EDS of the sample surface. The results of X-ray photoelectron spectroscopy （XPS） show the chrome-free passivation film composed ofZnO, SiO2, TiO2, Zn4Si207（OH）2, and SrF2. The anode zinc dissolution and the local pH value increase due to the cathode hydrogen ion reduction process result in the formation of the chrome-free passivation film. The macro-images of the chrome-free passivation films formed on electrodeposited zinc show that the color of the film changes from blue to iridescence with the increase of the immersion times.

Microstructure and magnetic properties of electrodeposited Gd-Co alloy films

Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The electroreduction of Co^2＋ and Gd^3＋ was investigated by cyclic voltammetry. The reduction of Co^2＋ is an irreversible process. Gd^3＋ cannot be reduced alone, but it can be inductively co-deposited with Co^2＋. Both the Gd content and microstructure of the prepared Gd-Co alloy films can be controlled by the deposited potential. The content of Gd was analyzed using an inductively coupled plasma emission spectrometer （ICPES）, and the microstructure was observed by scanning electron micrograph （SEM）. The films were crystallized by heat-treatment at 823 K for 30 s in Ar atmosphere, and then were investigated by XRD. The hysteresis loops of the Gd-Co alloy films were measured by a vibrating sample magnetometer （VSM）. The experimental results reveal that the deposited Gd-Co alloy films are amorphous, while the annealing causes the samples to change from amorphous to polycrystalline, thus enhancing their magnetocrystalline anisotropy and coercivity. Moreover, the magnetic properties of the Gd-Co alloy films depend strongly on the Gd content.

Effect of rubrene:P3HT bilayer on photovoltaic performance of perovskite solar cells with electrodeposited ZnO nanorods

Improved photovoltaic performance of perovskite solar cells is demonstrated through the synergistic effect of electrodeposited ZnO nanorods and rubrene：P3HT bilayer as electron and hole-transporting layers,respectively. Highly crystalline ZnO nanorods were obtained by electrochemical deposition in a chloride medium. Additionally, rubrene interlayer was able to passivate or cover the grain boundaries of perovskite film effectively that led to reduced leakage current. A perovskite solar cell optimized with ZnO nanorods and rubrene：P3HT bilayer achieved a maximum efficiency of 4.9% showing reduced hysteresis behavior compared with the device having P3HT as the only hole-transporting layer. The application of longer nanorods led to better perovskite infiltration and shorter charge carrier path length. These results highlight the potential of electrodeposited ZnO nanorods and rubrene：P3HT bilayer as charge selective layers for efficient perovskite solar cells.

Effects of the Composition of Electrodeposited Fe-Ni-P Alloy on the Thermostability and Magnetic Properties

The magnetic properties, structure defects of electrodeposited Fe-Ni-P alloys with various compositions and the thermostability at amorphous state have been studied by DSC, positron annihilation and electronic integrating instrument methods. The results show that the thermostability of amorphous Fe-Ni-P alloys increases with Fe content. Emergence and recrystallization of stable phases defer as the P content of the coating increases. The minimum H-c, B-r and P-h occur at 9.4 P (wt pet) content. Maximum H-c, B-r and P-h occur at the weight ratio of Fe to Ni equaling to 1/9.

Structure and characteristics of electrodeposited RE-Ni-W-P-B_4C-PTFE composite coatings

Hardness, friction and wear characteristics of electrodeposited RE Ni W P B 4C PTFE composite coatings were studied, and the reason for these fine characteristics was explained in respect of structure. The results show that 1) the structure of RE Ni W P B 4C PTFE composite coatings experiences a transformation process from amorphous to mixture then to crystal as the heat treatment temperature rises; 2) incorporating of B 4C greatly increases the hardness of the coating; 3) the wear resistance of the coating is best with heat treatment for 1?h at 300?℃, which is greatly superior to that of the other traditional coatings.

CYCLIC OXIDATION OF Ni-La_2O_3 COMPOSITE COATINGS ELECTRODEPOSITED ON NICKEL AND Fe26Cr STAINLESS STEEL

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Oxidation Behavior of Fe26Cr1Mo Stainless Steel in the Presence of Ni-La_2O_3 Electrodeposited Composite Film

The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an energy dispersive analytical X ray system(SEM/EDAX). The experimental results show that the oxide scale growing on Fe26Cr1Mo exposed at 900 ℃ spalled severely during cooling, while after the stainless steel was coated with the Ni La 2O 3 electrodeposited composite film, its high temperature cyclic oxidation resistance was significantly improved. The reason is that a La 2O 3 modified NiO scale, which has a superior adhesion to the substrate, was formed on the Fe26Cr1Mo stainless steel coated with Ni La 2O 3 composite film.

Properties of electrodeposited amorphous Fe-Ni-W alloy deposits

A new technique of electroplating amorphous Fe-Ni-W alloy deposits was proposed.The structure and morphology o Fe-Ni-W alloy deposit were detected by XRD and SEM.The friction and wear behavior of Fe-Ni-W alloy deposit were studied and compared with that of chromium deposit.The corrosion properties against 5% sodium chloride,5% sulfuric acid and 5% sodium hydroxide were also discussed.The experimental results indicate that Fe-Ni-W alloy deposits have superior properties against wea than hard chromium deposits under dry sliding condition.Under oil sliding condition,except their better wear resistance,the deposits can protect their counterparts against wear.The deposits plated on brass and AISI 1045 steel show good behavior against corrosion o 5% sodium chloride,5% sulfuric acid and 5% sodium hydroxide.The bath of electroplating amorphous Fe-Ni-W alloy deposits is environmentally friendly and would find widely use in industry.

MICROSTRUCTURE OF ELECTRODEPOSITED Ni-W-P-SiC COMPOSITE COATINGS

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Corrosion resistance of electrodeposited RE-Ni-W-P-SiC composite coating

Immersion experiment results show that corrosion rate of the as deposited RE Ni W P SiC composite coating in HCl solutions increases with the rise of HCl concentration. On the contrary, the corrosion rate of the composite coating after heat treatment decreases with increasing HCl concentration. The corrosion rates of the composite coatings in as deposited state and after heat treatment in H 2SO 4 and H 3PO 4 solutions respectively decrease with the rise of H 2SO 4 and H 3PO 4 concentrations. The corrosion rate of the composite coating as deposited in FeCl 3 solutions decreases with increasing FeCl 3 concentration, while the rate of the composite coating after heat treatment increases with the rise of FeCl 3 concentration. The corrosion rate of 316L stainless steel in the corrosion media of H 2SO 4, HCl, H 3PO 4 and FeCl 3 solutions at different concentrations increases with rising concentration. In addition, the corrosion rate of 316L stainless steel in the corrosion media of H 2SO 4, HCl, H 3PO 4 and FeCl 3 solutions respectively is much greater than that of the RE Ni W P SiC composite coating as deposited and after heat treatment in the same corrosion media. [

STUDY ON PROPERTIES OF PULSE ELECTRODEPOSITED RE-Ni-W-P-SiC COMPOSITE COATINGS

The effects of pulse frequency f and duty cycle r on the deposition rate, composition, morphology, and hardness of pulse electrodeposited RE （rare earth）-Ni-W-P-SiC composite coatings have been studied. The results indicate that pulse current can improve the deposition rate of RE-Ni-W-P-SiC composite coatings; W, P, and SiC contents in the coating decrease with the increase of pulse frequency and reach the lowest value at f = 33Hz, whereas the RE content in the composite coatings increases with the increase of pulse frequency. SiC content decreases with the increase of duty cycle, W content reaches the lowest value, and P content reaches the highest value at r = 0.4; pulse current and RE can lead to smaller size of the crystalline grains; however, the effects of different pulse frequency and duty cycle on the morphologies of RE-Ni-W-P-SiC composite coatings are not obvious. The hardness of RE-Ni-W-P-SiC composite coatings is the highest when the duty cycle is at 0.6 and 0.8 and pulse frequency is at 50Hz. At the same pulse frequency, the hardness of RE-Ni-W-P-SiC composite coatings at r= 0.8 is higher than that at r= 0.6.

Solid state interfacial reactions in electrodeposited Ni/Sn couples

Ni/Sn couples, prepared by sequentially electroplating Ni layers and Sn layers on metallized Si wafers, were employed to study the microstructures and growth kinetics of Ni-Sn intermediate phases, when the Ni/Sn couples were aged at room temperature or armealed at temperatures from 150 to 225℃ for various times. The results show that the NiSn phase and Ni3Sn4 phase are formed, respectively, in the aged couples and annealed couples. The Ni3Sn4 layer is continuously distributed between the Ni and Sn sides in the annealed Ni/Sn couples. The Ni3Sn4 growth follows parabolic growth kinetics with an apparent activation energy of 39.0 kJ/mol.

Microstructure of electrodeposited RE-Ni-W-P-SiC composite coating

The components and microstructure of the RE Ni W P SiC composite coating were analyzed by means of EPXDS, SEM and XRD. The results showed that the composite coating containing 5%～14%RE, 4%～7%SiC, 12%～15%P and 5%～6%W was obtained by use of appropriate bath composition and plating conditions. The as deposited composite coating is amorphous and it becomes mixture when the temperature is raised from 200 ℃ to 400 ℃. However, the composite coating is crystal when the temperature is over 400 ℃. Scanning electron microscopy indicates that the heat treatment temperature has no effect on the surface morphologies of the RE Ni W P SiC composite coating. This is to say that the composite coating has a better heat stability of microstructure and high temperature oxidation.

Preparation and tribological performance of electrodeposited Ni-TiB_2-Dy_2O_3 composite coatings

TiB2 and Dy2O3 were used as codeposited particles in the preparation of Ni-TiB2-Dy2O3 composite coatings to improve its performance. Ni-TiB2-Dy2O3 composite coatings were prepared by electrodeposition method with a nickel cetyltrimethylammonium bromide and hexadecylpyridinium bromide solution containing TiB2 and Dy2O3 particles. The content of codeposited TiB2 and Dy2O3 in the composite coatings was controlled by adding TiB2 and Dy2O3 particles of different concentrations into the solution, respectively. The effects of TiB2 and Dy2O3 content on microhardness, wear mass loss and friction coefficients of composite coatings were investigated. The composite coatings were characterized by X-ray diffraction （XRD）, inductively coupled plasma-atomic emission spectrometer （ICP-AES） and scanning electron microscopy （SEM） techniques. Ni-TiBE-Dy2O3 composite coatings showed higher microhardness, lower wear mass loss and friction coefficient compared with those of the pure Ni coating and Ni-TiB2 composite coatings. The wear mass loss of Ni-TiB2-Dy2O3 composite coatings was 9 and 1.57 times lower than that of the pure Ni coating and Ni-TiB2 composite coatings, respectively. The friction coefficient of pure Ni coating, Ni-TiB2 and Ni-TiB2-Dy2O3 composite coatings were 0.723, 0.815 and 0.619, respectively. Ni-TiBE-Dy2O3 composite coatings displayed the least friction coefficient among the three coatings. Dy2O3 particles in composite coatings might serve as a solid lubricant between contact surfaces to decrease the friction coefficient and abate the wear of the composite coatings. The loading-bearing capacity and the wear-reducing effect of the Dy2O3 particles were closely related to the content of Dy2O3 particles in the composite coatings.

Electrodeposited NiSe2 on carbon fiber cloth as a flexible electrode for high-performance supercapacitors

A flexible electrode of nickel diselenide/carbon fiber cloth(NiSe/CFC) is fabricated at room temperature by a simple and efficient electrodeposition method. Owing to NiSecharacter of nanostructure and high conductivity, the as-synthesized electrodes possess perfect pseudocapacitive property with high specific capacitance and excellent rate capability. In three-electrode system, the electrode specific capacitance of the NiSe/CFC electrode varies from 1058 F gto 996.3 F gat 2 A gto 10 A grespectively, which shows great rate capability. Moreover, the NiSeelectrode is assembled with an active carbon(AC) electrode to form an asymmetric supercapacitor with an extended potential window of 1.6 V. The asymmetric supercapacitor possesses an excellent energy density 32.7 Wh kgwith a power density 800 W kgat the current density of 1 A g. The nanosheet array on carbon fiber cloth with high flexibility, specific capacitance and rate capacitance render the NiSeto be regarded as the promising material for the high performance superconductor.

ELECTRODEPOSITED NiSCo ALLOY USED AS HYDROGEN EVOLUTION REACTION CATHODE IN WATER ELECTROLYSIS

NiSCo catalytic cathodes were obtained by electrodeposition in a typical Watt cell with addition of NH2CSNH2 and CoCl2. Using CoCl2 concentration, current density, temperature and pH value as main factors, an orthogonal experiment was designed to determine the optimum technological conditions according to HER overpotentials. The optimum technological conditions were obtained from the minimum HER overpoten-tial-70mV. The corresponding electrochemical parameters (Tafel slope b, exchange current density io) were determined by steady-state polarization curves. The content of S, Co and its microstructure were measured by EPMA and XRD.