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Carbon-based membranes are in the limelight as novel and high-performance materials for various applications. In this study, microporous carbon membranes were synthesized on porous alumina via a hydrothermal method from aqueous glucose solutions. The operating time and temperature for the hydrothermal treatment by evaluating the surface microstructure of the as-prepared membranes using various techniques like scanning electron microscopy (SEM) and electron probe microanalyzer mapping (EPMA). The SEM micrographs and the EPMA results indicate that the membranes formed were also deposited in the interiors of the porous alumina. A carbon membrane with few pinholes was prepared via a hydrothermal treatment at 200 °C for 5 h. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analyses suggest that the obtained membranes are composed of amorphous carbon, including hydroxy groups. The result of the gas transmission rate (GTR) measurement indicates that the pore size of the amorphous carbon membranes had pores with a diameter of ∼0.3 nm. The ideal gas selectivities for H2/N2, N2/CH4, and H2/SF6 were over Knudsen theoretical values, showing approximately 7.0, 9.5, and 13.5, respectively.

Chemical reactions can be efficiently carried out in microfluidic devices using a small amount of solution, meaning that fewer resources are required and less liquid waste is generated, making them...

This paper reports on the effect of Ti substitution on the thermal expansion behavior of Zr2-xTixS0.9P2O12-δ. The solid solubility limit of Ti in Zr2-xTixS0.9P2O12-δ was approximately x = 0.7 and could be classified into two types of Zr2-xTixS0.9P2O12-δ: x = 0–0.38 and x = 0.46–0.7. The all-Ti-substituted Zr2-xTixS0.9P2O12-δ had a smaller lattice volume than Zr2S0.9P2O12-δ. Zr2-xTixS0.9P2O12-δ (x = 0–0.38) showed a similar thermal expansion behavior to Zr2S0.9P2O12-δ, but Zr2-xTixS0.9P2O12-δ (x = 0.46–0.70) was less deformable than Zr2-xTixS0.9P2O12-δ (x = 0–0.38). In other words, Ti has two effects: reduction of the lattice constant and inhibition of the phase transition. Zr1.62Ti0.38S0.9P2O12-δ had the smallest lattice volume among the chemical compositions with a dynamic phase transition and had the lowest αv value of −114 ppm/K at 393–453 K.

A sensitized thermal cell is a new thermal energy device based on a dye-sensitized solar cell; thermally excited carriers in a semiconductor are used instead of photon-excited carriers in a dye. In...

Plasmonic photothermal conversion on metal nanostructures has attracted much attention because of its quick response and its local effects. In this work, we built an in-situ two-dimensional tempera...

The demand for the fabrication of nanostructures consisting of metal and dielectric is increasing with the development of new plasmonic optics. Since 1997, the presenter has produced various dielectric nanostructures by the bottom-up method and reported their optical and electrochemical properties such as light propagation in two-dimensional polystyrene colloidal crystals[1], the electron emission of diamond nanorods arrays[2], photochemical micro beakers composed of TiO2[3], etc. The advantages of the bottom-up method are that you can easily try various materials in addition to being able to easily perform experiments at the laboratory level. In this presentation, we will report about the various nanostructures fabricated using thermal dewetting process of metal/dielectric interface[4], focusing on the application to the plasmonic color pigment and microfluid devices. 1 Chem. Commun. 2004, 506. 2 Chem. Lett. 2000, 29, 534. 3 Chem. Lett. 1997, 925. 4 Nanoscale Adv., 2020, 2, 2271.

Titanium-doped hydroxyapatite (Ti-HAp, (Ca10-2x, Tix, hx) (PO4)6(OH)2, h: defect in Ca site) and hydrox- yapatite (HAp, Ca10(PO4)6(OH)2) powders were modified with an ethanol solution of molybdenyl acety- lacetonate (MoO2(C5H8O2)2) using chemisorption calcination cycle (CCC) technique, which provides metal oxide clusters. Their photocatalytic activity under UV illumination was evaluated by the decompo- sition of gaseous 2-propanol. The photocatalytic activity of the Mo-modified Ti-HAp samples increased concomitantly with increasing Mo concentration up to 0.72% against P. The highest photocatalytic activ- ity of Mo-modified Ti-HAp was about 13 times higher than that of Ti-HAp. The signal appearance of Mo (V) in electron spin resonance spectra and the decrease of photoluminescence intensity suggest electron transfer from the Ti-hybridized band to the MoOx cluster, which suppresses recombination of the pho- toinduced electron and hole pairs. The photocatalytic activity of Mo-modified HAp samples was attribu- ted to HOMO–LUMO excitation of MoOx cluster.

Using hydrothermal processing, we prepared cerium–bismuth solid solution oxide powder ((Ce0.73, Bi0.27)O2-δ, CBO) with brownish yellow color, a fluorite-type crystal structure, and decomposition activity on 2-naphthol in water at 50–75 °C in the dark. The contribution of the Mars – van Krevelen (MvK) mechanism was inferred from the activation energy and the valence change of Ce ion before and after decomposition. Photocatalysis by visible light illumination increased the CBO decomposition activity. Modification of MnOx onto the CBO provided higher decomposition activity on 2-naphthol in the dark or under visible light. The activation energy and the valence difference indicated that the dark activity was imparted by the MvK mechanism of MnOx. A contribution by oxygen diffusion in CBO was inferred as enhancing the MvK mechanism. The decomposition activity was obtained even at 30 °C. A synergistic effect achieved by the combination of CBO with MnOx was inferred from calculation of the reaction constants. Results also show that MnOx modification extended the CBO photon absorption range.

Sensitized thermal cells (STCs) are a new green power generation system operated by heating without a cooling temperature part. Here, we suggest Ag2S-sensitized thermal cells working at a low temperature (below 200 °C) and have a stylish sheet form. TiO2 was used for the electron transport layer, and ferrocene/ferricinium ions dissolved in dimethyl sulfoxide was selected for the redox couple ions. The Ag2S STCs generated power under light irradiation and at 90 °C in the dark. Electrochemical measurements and ICP-MS (inductively coupled plasma–mass spectrometry) indicated that thermally excited carriers caused the redox reaction and power generation occurred with heating. This result is an example of the first STC where the semiconductor part is less than a micrometer in size, not only improving the volume density of STC but also showing the possibility of STC with design awareness including flexibility.

Titanium-doped hydroxyapatite (Ti-HAp, (Ca10-2x, Tix, □x) (PO4)6(OH)2, □: defect in Ca site) powders were modified with a CaMoO4 aqueous solution. Then their photocatalytic activity under UV illumination was evaluated by the decomposition of gaseous 2-propanol. The crystal structure, morphology, light absorption, and specific surface area were almost unchanged by the modification, but small clusters were deposited onto the Ti-HAp surface. The photocatalytic activity of the Mo-modified samples increased concomitantly with increasing Mo concentration until 0.5% against Ti. The highest photocatalytic activity of Mo-modified Ti-HAp was about nine times higher than that of Ti-HAp. Computer modeling revealed that the contribution of MoO42− doping into the Ti-HAp structure plays no important role in the activity increase. A Mo(V) signal appeared by UV illumination in electron spin resonance spectra of Mo-modified Ti-HAp. The Mo modification decreased the photoluminescence intensity. These results suggest that photoinduced electrons can transfer from the Ti-hybridized band to the cluster, thereby improving the carrier separation efficiency and engendering higher photocatalytic activity.

You can find thermal energy everywhere in the world, including geothermal energy. Here we report an amazing battery that could supply power semi-permanently by simply burying the cell in a heat source and turning the switch on and off. We examined the discharge termination process of a sensitized thermal cell (STC), a new thermal energy conversion system for generating electrical power from heat previously reported by the authors. To observe this termination process, we constructed a new STC system using a narrow-bandgap semiconductor, germanium (Ge), and surprisingly found that the battery characteristics were restored after discharging by placing or burying the battery in a heat source. This discovery should bring us closer to solving global energy problems.

Amorphous precursor was synthesized hydrothermally and heated to 900 °C for 4 h to obtain a single-phase Zr 2 (WO 4 )(PO 4 ) 2 crystal with a specific surface area of approximately 11 m 2 /g. The crystallographic parameters were experimentally estimated and the resulting approximate values used for density-functional-theory calculations. The indirect band-gap energy was calculated to be approximately 3.7 eV, in good agreement with the experimental value. Finally, the photocatalytic activity of Zr 2 (WO 4 )(PO 4 ) 2 was investigated that revealed its high adsorption capacity for 2-propanol, decomposing it into acetone and CO 2 .

Concept The semiconductor-sensitized thermal cell (STC) is a new method for converting heat directly into electric power using dye-sensitized solar cells (DSSC). In the STC, the dye of DSSC was replaced with a semiconductor to allow the system to operate using heat instead of light.1 The number of thermally excited charges in a semiconductor is determined by the Fermi-Dirac distribution2; for example, Ge generates a number of thermally excited charges that exceeds the number of photons in room light at 80 ˚C. STC is expected as a powerful energy-harvesting device for wide applications such as IoT devices, distribution power sources, etc. Previous Results As the STC demonstration, liquid display was operated at 80 ˚C and Bluetooth devices was operated in the heat of asphalt.3 The biggest issue of STC is the power restore phenomena “in” heat. Initially, it was thought that the STC would stop generating electricity when it reached a chemical equilibrium at the set temperature. However, when the distance between the electrodes is close, the discharge performance restores when the circuit switch is turned off. In this presentation, we will focus on this recovery and electrochemically investigate what kind of phenomenon causes the recovery. Methods and Results To examine the recovery phenomenon, we focused on the electrolyte thickness. The STCs consist of three layers, an electrolyte layer sandwiched with a semiconductor working electrode and a counter electrode. We fabricated 4 different Ge-STCs with different electrolyte thicknesses and examined their electrochemical properties. Fluorine-doped tin oxide (FTO) was used for the counter electrode. The CuCl, CuCl2 and LiCl in PEG600 was used for the electrolyte.4 The 0.78, 1, 2 and 3 μL of the electrolyte were used when the thicknesses of the electrolyte were 85, 114, 228 and 342 μm, respectively, to eliminate the difference in the contact area of the electrode/electrolyte. The obtained cells were named according to their corresponding electrode distances (Cell-85, -114, -228 and -342). As a result, the cell with the narrowest electrode spacing and the lowest electrolyte mass discharged the longest (Figure). In the presentation, we will report these phenomena and electrochemical impedance analysis in detail. References (a) Matsushita, S.; Araki, T.; Mei, B.; Sugawara, S.; Inagawa, Y.; Nishiyama, J.; Isobe, T.; Nakajima, A., A sensitized thermal cell recovered using heat. J. Mater. Chem. A 2019, 7, 18249-18256; (b) Matsushita, S.; Tsuruoka, A.; Kobayashi, E.; Isobe, T.; Nakajima, A., Redox reactions by thermally excited charge carriers: towards sensitized thermal cells. Mater. Horiz. 2017, 4, 649–656. Inagawa, Y.; Isobe, T.; Nakajima, A.; Matsushita, S., Ag2S-Sensitized Thermal Cell. J. Phys. Chem. C 2019, 123 (19), 12135-12141. Kohata, H.; Obinata, M.; Ikeda, T.; Sekiya, H.; Mei, B.; Wang, Y.; Mizukoshi, K.; Isobe, T.; Nakajima, A.; Matsushita, S., Power Generation at Room Temperature -How to Design of the Sensitized Thermal Cell-. Research Square 2021, 384614. (a) Ikeda, T.; Sekiya, H.; Kohata, H.; Isobe, T.; Nakajima, A.; Matsushita, S., Role of the ions in the Ge/(CuCl, CuCl2 and LiCl)/FTO-sensitized thermal cell. J. Electroanal. Chem. 2021, 895, 115413; (b) Matsushita, S.; Sugawara, S.; Ikeda, T.; Araki, T.; Sekiya, H.; Kohata, H.; Isobe, T.; Nakajima, A., Fermi Level Dependence of a Working Electrode on the Open Circuit Voltage in a Sensitized Thermal Cell. Chem. Lett. 2020, 49 (9), 1013-1016. Figure 1

Efficient and low-cost thermal energy-harvesting systems are needed to solve the global energy problem. Here, we suggest a new energy conversion system for generating electric power from heat without a cooling element. This device is a sensitized thermal cell (STC) based on a dye-sensitized solar cell. A semiconductor is used instead of the dye, and as a result, this system can work by using heat instead of light. To prove the efficacy of this system, we focused on an organic perovskite. This material has been used in a sensitized solar cell, and recent calculations show that it can generate several thermally excited charges at temperatures over 60 °C. Thus, if this perovskite cell can generate electric power with both light irradiation and thermal excitation, the STC concept would be perfectly proven, and the device succeeds thanks to the careful analysis of the perovskite’s unstableness. This is the dawn of the three-dimensional utilization of heat.

The effective utilisation of thermal energy is crucial to a world aiming at sustainable development goals. The sensitised thermal cell (STC) is a new thermal energy conversion technology, which was reported in 2017, for generating electricity via the redox reactions of electrolyte ions with thermally excited carriers The effective utilisation of thermal energy is crucial to a world aiming at sustainable development goals. The sensitised thermal cell (STC) is a new thermal energy conversion technology, which was reported in 2017, for generating electricity via the redox reactions of electrolyte ions with thermally excited carriers in semiconductors. STC is attracting attention as a technology that could affect oil prices globally. Here, we report the successful construction of STC, which discharges and recovers well at room temperature, by studying the interelectrode and ion diffusion distances. The fabricated STC is thinner than 0.5 mm and can be rendered flexible. Further, STCs, which possess a power generation capacity of 0.1 mA, 100 mV per 1 mm2 area, and shall be installed “in” internet-of-things (IoT) devices, drainage pipes, and walls in the future.in semiconductors. STC is attracting attention as a technology that could affect oil prices globally. Here, we report the successful construction of STC, which discharges and recovers well at room temperature, by studying the interelectrode and ion diffusion distances. The fabricated STC is thinner than 0.5 mm and can be rendered flexible. Further, STCs, which possess a power generation capacity of 0.1 mA, 100 mV per 1 mm2 area, and shall be installed “in” internet-of-things (IoT) devices, drainage pipes, and walls in the future.

The effective utilisation of thermal energy is crucial to a world aiming at sustainable development goals. The sensitised thermal cell (STC) is a new thermal energy conversion technology, which was reported in 2017, for generating electricity via the redox reactions of electrolyte ions with thermally excited carriers in semiconductors. STC is attracting attention as a technology that could affect oil prices globally. Here, we report the successful construction of STC, which discharges and recovers well at room temperature, by studying the interelectrode and ion diffusion distances. The fabricated STC is thinner than 0.5 mm and can be rendered flexible. Further, STCs, which possess a power generation capacity of 0.1 mA, 100 mV per 1 mm2 area, and shall be installed “in” internet-of-things (IoT) devices, drainage pipes, and walls in the future.

The sensitized thermal cell (STC) is a battery that can convert heat directly into electric power at low environmental temperatures (100°C or lower). It can be buried in the ground and generate electricity directly from the Earth’s crust. This STC was originally suggested by the authors in 2017 (Mater. Horiz., 2017,4, 649-656), and media in different continents and countries, including Europa, the United States, Asia, Arab, and Africa, reported the STC as a sensational technique that can directly affect the oil price. The most valuable feature of the STC is, after the electricity generation was stop, the reaction could restart with a simple flip of an on/off switch in the external circuit after the electricity generation was stopped. These batteries could be, for example, buried in a geothermal spot and work as a power plant.

Graphical abstract, Two cerium molybdates (Ce2Mo3O12 and γ-Ce2Mo3O13) were prepared using either polymerizable complex method or hydrothermal process. The obtained powders were almost single-phase with different cerium valence. Both samples were found to have antiviral activity against bacteriophage Φ6. Especially, γ-Ce2Mo3O13 exhibited high antiviral activity against both bacteriophage Φ6 and SARS-CoV-2 coronavirus, which causes COVID-19. A synergetic effect of Ce and molybdate ion was inferred along with the specific surface area as key factors for antiviral activity.

Efficient and low-cost thermal energy-harvesting systems are needed to solve the global energy problem. Here, we suggest a new energy conversion system for generating electric power from heat without a cooling element. This device is a sensitized thermal cell (STC) based on a dye-sensitized solar cell. A semiconductor is used instead of the dye, and as a result, this system can work by using heat instead of by light. This STC was created that generates electricity by “placing” or “burying” the cell in a heat source. In this invited talk, we will present the latest results of the STC research.

We report a method to modulate spontaneously formed microwrinkle patterns on a metal-capped elastomer surface by introducing lithographic patterns (structures) on the original surface as spatial triggers for directed wrinkling. The lithographic patterns are designed to have approximately the same lateral length scales as the characteristic wavelength of the microwrinkles by utilizing self-assembled two-dimensional microsphere arrays with hexagonal packing as a lithographic mask. When the lateral periodicity of the lithographic pattern is close to the wavelength of wrinkles, a novel directional order originating from the hexagonal packing of microspheres is induced. Otherwise, the wrinkle crests tend to form along the small ridges of the lithographic structure. The compression direction-dependent and reversible ordering of wrinkle patterns by compressive strain is also found for patterns with directional order.

Efficient and low-cost thermal energy-harvesting systems are crucial to solve the global energy problem. A new energy conversion system for the generation of electric power directly from heat energy is described herein. The device is a sensitized thermal cell (STC) based on a dye-sensitized solar cell. In the established system, thermally-excited electrons in a semiconductor were utilized instead of photon-excited electrons in a dye. Consequently, the STC generated electricity by “placing” or “burying” the cell in the heat source. The present study summarized the recent results of the STC and the difference between photo excitation and thermally excitation.

Powders of cerium (Ce)-substituted and tungsten (W)-substituted La2Mo2O9 (LMO) were prepared using polymerizable complex method. Their antiviral and antibacterial performances were then evaluated using bacteriophage Qβ, bacteriophage Φ6, Escherichia coli, and Staphylococcus aureus. The obtained powders, which were almost single-phase, exhibited both antiviral and antibacterial properties. Effects of dissolved ions on their antiviral activity against bacteriophage Qβ were remarkable. A certain contribution of direct contact to the powder surface was also inferred along with the dissolved ion effect for antiviral activity against bacteriophage Φ6. Dissolved ion effects and pH values suggest that both Mo and W are in the form of polyacids. Antiviral activity against bacteriophage Φ6 was improved by substituting Ce for La in LMO. Similarly to LMO, Ce-substituted LMO exhibited hydrophobicity. Inactivation of alkaline phosphatase enzyme proteins was inferred as one mechanism of the antiviral and antibacterial activities of the obtained powders., Graphical abstract Unlabelled Image, Highlights • Ce and W were partially substituted in La2Mo2O9 (LMO). • These powders inactivated E. coli, S. aureus, bacteriophage Qβ, and bacteriophage Φ6. • Inactivation of alkaline phosphatase enzyme proteins on these materials was confirmed. • Antiviral activity against bacteriophage Φ6 of LMO was improved by substituting Ce. • Hydrophobicity and UV shielding performance were also confirmed for this material.

Plasmonic color is an elegant color resulting from light absorption and emission induced by collective oscillation of free electrons in a metal and enables unprecedented new color expression. In particular, Al plasmonic color is highly desirable because of the low cost and high stability of Al. Here, we report a new cost-effective, wide-area fabrication method for an Al metal–insulator–metal (MIM) plasmonic nanostructure using a vapor deposition and sintering process.

This paper proposes Kelvin probe force microscopy (KFM) as a new measurement method of plasmon phenomenon. The surface potential of two arrays, namely, a monomeric array and a tetrameric array, of gold nanodiscs (600 nm diameter) on a silicon substrate fabricated by electron beam lithography was investigated by KFM with the view point of irradiation light wavelength change. In terms of the value of the surface potential, contrasting behaviour, a negative shift in the monomeric disc array and a positive shift in the tetrameric disc array, was observed by light irradiation. This interesting behaviour is thought to be related to a difference in localised plasmons caused by the disc arrangement and was investigated from various viewpoints, including Rayleigh anomalies. Finally, this paper reveals that KFM is powerful not only to investigate the plasmonic behaviour but also to predict the electron transportation.

The relation between surface homogeneity and internal fluidity for a droplet sliding on a surface tilted at acute and obtuse angles was investigated using two hydrophobic fluoroalkylsilane (FAS) coatings with different roughness. The coatings (FAS-smooth and FAS-rough) were prepared on an Si substrate using chemical vapor deposition or soaking methods and were tilted at 35° or 145°. Sliding velocity of water droplets on the surface tilted at 145° was greater than that tilted at 35° for both coatings. For 35° tilting, the dominant mode of the sliding velocity was slipping for FAS-smooth, whereas rolling governed the entire sliding velocity for FAS-rough. The slipping mode was more important than the rolling one for both coatings when they were tilted at 145°. The change of slipping velocity was more remarkable than that of rolling one for both coatings between 35° and 145° tilting. Results show that the difference in gravity direction and contact area of the droplets contributed to this tilt angle dependence of the sliding velocity. When a droplet slid down with acceleration on FAS-smooth surface, the coefficient of the viscous drag force correlated with the velocity ratio (Utotal/Uslip).

Optical tweezers are powerful and flexible tools for manipulating micrometre-sized objects. Recently, metal nanostructures are gathering attention to trap nanometre-sized objects to utilize their p...