Journal of the Korean Ceramic Society

An, Byung-Gi; Kim, Hong-Rae; Chang, Young Wook; Park, Jae-Gwan; Pyun, Jae-Chul

doi: 10.1007/s43207-021-00141-5pmid: N/A

Cadmium sulfide (CdS) is an II–VI semiconductor with a direct bandgap of 2.4 eV; it has been used for various applications, such as nonlinear optical devices, flat-panel displays, light-emitting diodes, lasers, logic gates, transistors, photoresistors, solar cells, infrared waveguides, and splitters. CdS nanostructures have been synthesized through two different routes: (1) vapor-phase growth and (2) liquid-phase growth. The vapor-phase growth system can yield highly pure single-crystal nanostructures, and liquid-phase growth has been carried out through chemical or electrochemical reactions in solution with templates. The fabricated nanostructures of CdS showed a relatively low work function, high refractive index, excellent transport properties, good chemical capability, thermal stability, high electronic mobility, and piezoelectric properties. For these reasons, CdS photosensors have been produced using various nanostructures of CdS, such as nanorods, nanoribbons, and nanowires. For the fabrication of CdS nanowire photosensors, many different approaches have been demonstrated to connect nanostructures in devices and circuits using various techniques, such as dry transfer, wet transfer, and contact printing. Each method has practical advantages and drawbacks in the implementation of nanostructures in devices. In this article, the synthesis of CdS nanostructures and the fabrication of photosensors based on the CdS nanostructures are reviewed.

Kim, In Yea; Ko, Jaehwan; Ahn, Tae-Young; Cheong, Hae-Won; Yoon, Young Soo

doi: 10.1007/s43207-021-00152-2pmid: N/A

Fossil fuels are widely used around the world, resulting in adverse effects on global temperatures. Hence, there is a growing movement worldwide towards the introduction and use of green energy, i.e., energy produced without emitting pollutants. Korea has a high dependence on fossil fuels and is thus investigating various energy production and storage technologies for producing and using green energy. Renewable energy technologies are essential for producing green energy, and energy storage technologies are necessary for its effective use. In Korea, the renewable energy technologies of most interest are solar power generation and fuel cells, followed by energy storage, transportation. This review intends to provide information about the energy materials currently being researched to develop these energy technologies.Graphical abstract[graphic not available: see fulltext]

Oh, Won-Chun; Biswas, Md Rokon Ud Dowla

doi: 10.1007/s43207-021-00116-6pmid: N/A

In this investigation, 3D shaped BiVO4-GO composites have been set up with various proportions of BiVO4 by an altered hydrothermal strategy. This example is described by X-ray diffraction (XRD), Scanning electron microscopy (SEM), FT-IR, UV–Vis diffuse reflectance spectra (DRS), Raman spectroscopy, transmission electron microscopy (TEM) procedures and UV–Vis spectroscopy. BiVO4 could cover well on the outside of graphene sheets. BiVO4-GO composites with a reasonable expansion measure of BiVO4 indicated higher photocatalytic movement than plain BiVO4 toward fluid stage corruption of methylene blue (MB), texbrite BAC-L and texbrite NFW-L under obvious light illumination.

Kim, Sung-Eun; Lee, Hong-Sub

doi: 10.1007/s43207-021-00139-zpmid: N/A

Resistive RAM (ReRAM) is a promising candidate for next-generation non-volatile memory; it uses resistive switching behavior by electrochemical migration of oxygen vacancies inside of transition metal oxides. Controlling the oxygen content of the resistive switching material is required during the film deposition step for resistive switching to occur. This study Pledemonstrated an electric field-assisted photochemical metal–organic deposition (EFAPMOD) method for controlling the oxygen content of amorphous phase TiOx thin film, a commonly used material for ReRAM. Various voltages (0, + 10, + 15, + 20 V) were applied using a specially designed photomask coated with a transparent conductive oxide film during the photochemical reaction by UV irradiation. As a result, the oxygen content at the film top surface could be controlled according to the magnitude of applied voltage. This effect was confirmed by X-ray photoelectron spectroscopy (XPS) and I–V characteristic measurement. The applied positive voltage induced high oxygen content at the top interface of the TiOx film, and the local region possessing high oxygen content (high resistance) induced a resistive switching event. The TiOx amorphous film formed by EFAPMOD + 20 V showed stable and consistent resistive switching behavior.

Lee, Dong-Kyu; Wee, Sung-Jun; Jang, Kyung-Jun; Han, Mi-Kyung; Surendran, Subramani; Cho, Sung Yong; Kim, Joon Young; Lee, Sang-Kyu; Sim, Uk

doi: 10.1007/s43207-021-00142-4pmid: N/A

The electrochemical approach for the feasible ammonia production via N2 fixation is well-thought-out to be an eco-friendly strategy to replace the polluting Haber Bosch process. However, the impeding activation barrier of strong N≡N and the competing hydrogen evolution reaction constrain the Faradaic efficiency of the electrochemical nitrogen reduction reaction. Therefore, the implication of innovative strategies for designing an active electrocatalyst remains a crucial criterion to deliver operational efficiencies during electrochemical reactions. This study proposes a unique fabrication of three-dimensional (3D)-architectured electrodes encompassed with cobalt-rich tungsten carbide (Co-WC) as an electrocatalyst using a 3D-printing technique for the efficient electrochemical nitrogen reduction reaction. Here, the cobalt acts as a binder between tungsten carbide particles after sintering, and the particles are bonded to each other. The 3D-printing process generates 3D-architectured Co-WC electrodes with an average particle size of 1–3 µm through precise control of printing parameters. The electrochemical performance of the 3D-architectured Co-WC electrode reveals a better selectivity for N2 reduction under ambient condition. Substantially, the 3D-architectured Co-WC electrodes demonstrate an improved ammonia yield rate of 34.61 μg h−1 cm−2 and Faradaic efficiency of 2.12% at an applied potential − 0.6 V (vs. RHE). 3D-printing techniques can be an effective design method for manufacturing 3D-architectured active material with superior performance and selectivity.

Kumar, Aniket; Kim, In-Ho; Mathur, Lakshya; Kim, Ho-Sung; Song, Sun-Ju

doi: 10.1007/s43207-021-00143-3pmid: N/A

With the ever-growing demand for clean and viable energy sources, the possibility and need to use a multifunctional energy system having integrated energy storage and conversion capacity has been intensified in current times. To fulfill this requirement, a search for an active material having an efficient bifunctional capacity of both hydrogen evolution reaction (HER) and supercapacitor is an essential requirement. The metal polyphosphate with the advantage of abundance, environmental friendliness, low cost, and reliable activity make it an emerging class of novel material for the present research. Herein, for the first time, the comparison of the amorphous and crystalline form of tin polyphosphate-based electrode was assessed toward hydrogen evolution reaction and supercapacitor. Considering the synergistic influence of abundant tin polyphosphate and the three-dimension structure of nickel substrate, we unswervingly deposited well-defined hierarchical in-situ amorphous SnPxOy and ex-situ crystalline SnPxOy over Ni foam using the one-step hydrothermal route. Impressively, amorphous SnPxOy/NF electrode required less over the potential of the only 100 mV with Tafel slope of 50 mV dec−1 to attain a current density of 10 mA cm−2 in comparison to crystalline SnPxOy/NF electrode showing over the potential of the only 170 mV with Tafel slope of 80 mV dec−1 to attain the same current density in 1 M KOH. Additionally, we investigated this electrode in a supercapacitor and found that amorphous SnPxOy/NF delivers a good specific capacitance of 580 F g−1 at a current density of 1 A g−1, greater rate capability, and cyclic stability. Hopefully, this study may demonstrate a promising technique for the preparation of ample, low-cost electrodes for future applications in both HER and supercapacitors applications.

Patil, Deepak Rajaram; Park, Sung Hoon; Patil, Seema; Kumar, Ajeet; Ryu, Jungho

doi: 10.1007/s43207-021-00144-2pmid: N/A

Magnetoelectric (ME) laminates consisting of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT)-based single crystals have recently attracted significant interest owing to their excellent piezoelectric properties. Particularly, ME laminates with d15-mode single crystals exhibit the strongest ME coupling, but the fabrication of ME laminates with 15 shear modes is challenging. Herein, we propose the generation of a stretch–shear mode (d15-mode) by clamping the opposite ends of the top and bottom magnetostrictive layers in symmetric ME laminates. Two different shear-stress-induced ME laminates were fabricated using Metglas/Galfenol as magnetostrictive layer, and 15-PMN-PZT as a piezoelectric layer. The ME laminates were studied under two different conditions, unclamped and clamped. Under unclamped condition, Galfenol/15-PMN-PZT/Galfenol (Metglas/15-PMN-PZT/Metglas) laminate showed maximum αME value of 1.71 V/cm∙Oe (0.62 V/cm∙Oe), while under clamped condition, Galfenol/d15-PMN-PZT/Galfenol (Metglas/15-PMN-PZT/Metglas) laminate exhibited an enhanced αME value of 2.40 V/cm∙Oe (0.87 V/cm∙Oe), indicating successful generation of the stretch–shear mode. Under clamped condition, αME was enhanced by 140% compared with the that of the unclamped case, suggesting a 40% (0.25 V/cm∙Oe) contribution from the pure shear ME voltage coefficient along with the longitudinal extension contribution.

Noori, R.; Alizadeh, Parvin; Afghahi, S. S. S.

doi: 10.1007/s43207-021-00145-1pmid: N/A

In this study, different initial compositions of Y-Si-Al-O-N system were selected in such a way that the sintered phase structures to be obtained as α-SiAlON, β-SiAlON and α/β SiAlON with various amounts of dissolution in each of these phases. Sintering parameters for all samples were the same and applied by SPS technique. Densification and phase transformation progress at lower temperature and shorter period resulting in a fine-grained structure because of high heating rate along with inducing the pulsed current. Dielectric properties of samples were investigated within the considered 8.2–12.4 GHz frequency range. In the case that the additives were not participated as solutes in the structure of Si3N4 and aggregated in the amorphous form at grain boundaries, dielectric constant was decreased; otherwise, when they were dissolved in the structure, it led to enhancement of bond length in Si3N4 and change of its covalent feature into ionic feature associated with increase of dielectric constant. Examination of dielectric loss peak revealed that by increase of amount of dissolution, the resonance peak shifts to lower frequencies indicating the longer natural period of corresponding dipoles which may be caused by increase of bond length and decrease of its strength.

Park, Ji Yeon; Kim, Daejong; Lee, Hyeon Guen; Kim, Weon-Ju

doi: 10.1007/s43207-021-00146-0pmid: N/A

The SiCf/SiC composite tubes were manufactured by three different manufacturing methods: rotation CVI (chemical vapor infiltration), nanorod-assisted CVI, and forced CVI, and the C-ring compression strength of the tubes was evaluated. In the rotation CVI method, the supply route of the source gas greatly influenced the formation of a homogeneous microstructure, and supplying gas from both directions of the tube could improve the microstructure homogeneity. The longer the gas supply time from the inside to the outside, the better was the C-ring strength. In the nanorod-assisted CVI method, the existence of SiC nanorods increased the strength by 25% (338–429 MPa) and the macro-pore fraction by 44% (7.6% to 3.4%) compared to the conventional CVI tube. In tubes with large diameters (100 mm and 150 mm) made of forced CVI, meaningful strength values were measured even at values outside the range of 1 < b/t < 2, which is the boundary condition of the C-ring strength in standard test method. Therefore, further evaluation is necessary.

Pimchan, Patcharaporn; Tana, Pornpan; Jansawang, Natchanok

doi: 10.1007/s43207-021-00147-zpmid: N/A

The hybrid materials (HBs) of metal (II)-8-hydroxyquinoline complexes, namely Coq2, Niq2 and Znq2 (Mq2), in the mesoporous silica were prepared, as well as their optical properties were investigated. The mesoporous silica (MCM) was synthesized by colloidal reaction of sodium silicate solution from the rice husk. After that the HBs was prepared by the solid–solid reactions between mesoporous silica, transition metals and 8-hydroxyquinoline. The incorporation of HBs were characterized by SEM, FT–IR, AAS, as well as PL. The photoluminescence maxima and intensities of the HBs varied depending on the spectro-chemical series and electron configuration as well as microstructure of metal complexes and mesoporous characteristics. The photoluminescence of the products increased in the order of Coq2@MCM < Znq2@MCM < Niq2@MCM. The host mesoporous silica improves photoluminescence properties such that the PL intensities of Mq2 complexes into MCM were higher than those of the free complexes because mesoporous silica can reduce the luminescence quenching and enhance the complete metal-to-ligand charge transfer of metal complexes. Especially, the Niq2 and Znq2 in the mesoporous silica revealed the excellent photoluminescence property.