Hydrogen energy is a promising source of renewable and clean energy for various industries, such as chemical, automobile, and energy industries. Electrolysis of water is one of the basic methods for the production of hydrogen energy. However, the high overpotential of the oxygen evolution reaction (OER) in water electrolysis has hindered the effective production of hydrogen using this method. Thus, the development of high-efficiency non-precious metal-based electrocatalysts for OER is extremely significant. In this study, we adopted a one-step hydrothermal method to fabricate Ni-based catalysts with N/Sdual doped graphene oxide/carbon nanotube (GO/CNT) supports using thiourea ( CH4N2S) and urea as the S source and the N source. It was observed that the amount of thiourea utilized in the synthesis of the catalyst affected the morphology, composition, and the electrochemical properties of the catalyst. For a GO/CNT-to-thiourea mass ratio of 1:10, the catalyst exhibited the highest activity, where the OER overpotential was 320 mV at a current density of 10 mA/cm2. This was attributed to the high specific surface area, high conductivity, and fast electron transport channels of the N/S-dual doped GO/ CNT composite. Furthermore, sulfurization of the Ni particles to form nickel sulfide played a significant role in enhancing the catalytic performance.

In this work, a simple nonenzymatic glucose sensor has been proposed based on coconut shell charcoal (CSC) modified nickel foil as working electrode in a three-electrode electrochemical cell. Charcoal was prepared by the pyrolysis of coconut shells. The most important advantages of coconut shells are cost-effectiveness and their abundance in nature. The morphology and phase of the CSC powder were characterized by scanning electron microscopy and X-ray diffraction. The electrochemical performance of the CSC powder coated Nickel foil electrode was investigated by cyclic voltammetry and chronoamperometry. The sensor shows a higher sensitivity of 2.992 mA cm−2 mM−1 in the linear range of 0.5–5.5 mM and slightly lower sensitivity of 1.1526 mA cm−2 mM−1 in the range of 7–18.5 mM glucose concentration with a detection limit of 0.2 mM. The anti-interference property of CSC powder also was investigated and found that the response of interfering species was less significant compared to glucose response. The proposed sensor offers good sensitivity, wide linear range, and a very low response to interfering biomolecules.

Abstract In this study, we investigated that the activated carbon (AC)-based supercapacitor and introduced SIFSIX-3-Ni as a porous conducting additive to increase its electrochemical performances of AC/SIFSIX-3-Ni composite-based supercapacitor. The AC/SIFSIX-3-Ni composites are coated onto the aluminum substrate using the doctor blade method and conducted an ion-gel electrolyte to produce a symmetrical supercapacitor. The electrochemical properties of the AC/SIFSIX-3-Ni composite-based supercapacitor are evaluated through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge tests (GCD). The AC/SIFSIX-3-Ni composite-based supercapacitor showed reasonable capacitive behavior in various electrochemical measurements, including CV, EIS, and GCD. The highest specific capacitance of the AC/SIFSIX-3-Ni composite-based supercapacitor was 129 F g−1 at 20 mV s−1.

Vertically oriented nickel nanowire arrays with a different diameter and length are synthesized in porous anodic aluminium oxide templates by an electrodeposition method. The pore diameters of the templates are adjusted by controlling the anodization conditions and then they are utilized as templates to grow nickel nanowire arrays. The nickel nanowires have the average diameters of approximately 25 and 260 nm and the crystal structure, morphology and microstructure of the nanowires are systematically investigated using XRD, FE-SEM and TEM analysis. The nickel nanowire arrays show a magnetic anisotropy with the easy axis parallel to the nanowires and the coercivity and remanence enhance with decreasing a wire diameter and increasing a wire length.

Investigation of influence the morphology of initial powder particles, application pore-formers for sintering of nickel powders and application of flux for sintering of aluminum was made. Using different methods was prepared material with size of porous in wide range size of pores (). Using the flux for gravity sintering of aluminum in air atmosphere was manufactured porous material with porosity about 45%..

Laser additive direct deposition of metals is a new rapid manufacturing technology, which combines with computer aided design, laser cladding and rapid prototyping. The advanced technology can build fully-dense metal components directly from CAD files with neither mould nor tool. Based on the theory of this technology, a promising rapid manufacturing system called "Laser Metal Deposition Shaping (LMDS)" is being developed significantly. The microstructure and mechanical properties of the LMDS-formed samples are tested and analyzed synthetically. As a result, significant processing flexibility with the LMDS system over conventional processing capabilities is recognized, with potentially lower production cost, higher quality components, and shorter lead time.

제1세대 니켈계 단결정 초합금인 CMSX 6를 사용하여 셀렉타법으로 진공 정밀주조하여 단결정을 제작하였다. 주형온도 약 1500˚C, 주입온도 약 1630˚C와 용탕 주입 직후 주형을 2.5mm/분 속도로 하강시켜 단결정을 성장시켰다. 단결정 주조조직에서 기지와 공정조직은 γ' 석출물(Ni3(Al, Ti)) 모양과 크기에 따라 각각 모두 두영역으로 구분되었으며, 공정조직의 Ti함랗은 기지보다 높았다. 즉, EPMA 및 CBED 분석 등으로 γ' 석출물을 분석한 결과, 기지내의 γ'은 크기가 0.5~0.7μm 이하이며 화학조성상 Ni3Al에 가까웠으며 격자구조도 Ll2를 나타내었다. 반면에 공정조직에 가까울수록 γ' 크기는 1.0μm보다 컸으며, 모양도 판상형의 거대한 모양으로 바뀌었다. 화학조성 또한 Ni3Ti에 가까웠으며 격자구조도 D O24를 나타내었으므로 수지상과 공정조직의 γ' 석출물은 화학조성 및 격자구조가 상이함을 알 수 있었다.