A novel visible-to-near-infrared (visible-to-NIR) light-driven photocatalyst was prepared by loading a dibenzo-BODIPY-phenothiazine conjugate dye 1 as a panchromatic photosensitizer on hierarchical ...porous TiO2 (HPT) semiconductor. The sensitizer 1, which absorbed visible light at 638 and 440 nm with molecular extinction coefficients (ε) of 1.23 × 105 and 1.80 × 104 M–1 cm–1, respectively, in THF due to the dibenzo-BODIPY and phenothiazine-based D−π–A systems, respectively, showed panchromatic absorption up to 780 nm when deposited on the Pt/HPT photocatalyst to produce Pt/HPT500/1. The photocatalytic activities were investigated in the presence of ascorbic acid as a sacrificial agent in phosphate buffer solution under irradiation with λ > 400 nm using a 300 W Xe lamp at 100 mW cm–2 light intensity. After 10-h irradiation, the system achieved a remarkable catalytic activity for the production of H2 with a turnover number (TON) value of 11100. The sustained activity was suggestive after two sequences of 10-h illumination-period, whereas we found somewhat decrease in the photoactivity for the third run, although a TON value of 5650 still remained. The apparent quantum yields were evaluated by monitoring H2 production for each monochromatic light irradiation (λ = 420, 530, 600, 670, 700, and 750 nm). They were found to be consistent with the absorption profile, proving the panchromatic hydrogen generation sensitized by 1. The active absorption band of dye 1 in the entire visible-to-NIR spectrum led to production of a dye-sensitized photocatalytic system with a light-to-fuel efficiency of 6.96% in the initial irradiation period. This study provides important information for the development of metal-free organic photosensitizers with a wide spectral response up to the NIR region for photocatalytic water-splitting H2 production.
Dye-sensitized photoelectrochemical cells (DSPECs) composed of a new near-infrared BODIPY dye D1 that is co-deposited with a ruthenium water oxidation catalyst C1 have been fabricated. The devices at ...pH 7.2 showed an excellent Faradaic efficiency of H
production (65.8%) that was 5.4 times larger than that of a triphenylamine photosensitizer D2 and C1-coadsorbed cell.
The highest theoretical efficiency of double junction solar cells is predicted for architectures with the bottom cell bandgap (Eg) of approximately 0.9–1.0 eV, which is lower than that of a typical ...Si cell (1.1 eV). Cu(In,Ga)(Se,S)2 (CIGS) solar cells exhibit a tunable Eg depending on their elemental composition and depth profile. In this study, various CIGS solar cells with Eg ranging from 1.02 to 1.14 eV are prepared and a spectrum splitting system is used to experimentally demonstrate the effect of using lower-Eg cells as the bottom cell of two-junction solar cells. The four-terminal tandem cell configuration fabricated using a mixed-halide perovskite top cell (Eg = 1.59 eV; stand-alone efficiency = 21.0%) and CIGS bottom cell (Eg = 1.02 eV; stand-alone efficiency = 21.5%) with a 775-nm spectral splitting mirror exhibits an efficiency of 28.0% at the aperture area of 1 cm2.
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•CIGS bottom solar cells with Eg ranging from 1.02 to 1.14 eV are prepared•The lower the Eg of CIGS bottom cell, the higher PCE of PVK/CIGS tandem solar cell•PCE of 28% was demonstrated in a 1 cm2-sized PVK/CIGS 4-Terminal solar cell•The result can be utilized to design better tandem solar cell in the future
Inorganic Materials; Optical Materials; Materials Science; Materials Application; Energy Materials
At the J-PARC muon facility (MUSE), new beamlines started operation recently. H-line is a high-intensity pulsed muon beamline for fundamental physics experiments. The first beam of the H-line was ...delivered to its first branch (H1 area) in January 2022, where a precise measurement of the muonium hyperfine structure and a search for μ-e conversion will be conducted. Further extension of the second branch of the H-line for a muon g-2/EDM experiment and a transmission muon microscope project is also ongoing. In addition, the second branch of the surface muon beamline (S2 area of the S-line) was opened for a muonium 1S-2S spectroscopy experiment in FY2021. In this paper, the recent upgrade and present status of the J-PARC muon facility and its prospects are presented.
Much attention has been devoted to the synthesis of dyes that absorb near-infrared (NIR) radiation because of numerous demands for them as functional materials. Given that NIR sensitizers applicable ...to p-type dye-sensitized solar cell (DSSC) devices are extremely rare, π-extended dibenzo-BODIPY sensitizer 1 containing triphenylamine and nitrothiophene units was synthesized; the absorption spectrum of 1 showed an intense absorption band at 730 nm with a molar extinction coefficient of 7.14 × 104 M−1 cm−1. A p-type DSSC device with a 1-loaded NiO electrode was fabricated and its cell performance was investigated. It showed an open circuit voltage (VOC), a short circuit current density (JSC), and a fill factor (FF) of 79 mV, 0.61 mA cm−2, and 0.25, respectively. Consequently, the power conversion efficiency was 0.012%. Its performance was low, mainly owing to very fast recombination between the NiO and reduced dye at the surface of the electrode. However, EQE measurement showed that the 1-loaded p-type DSSC devices convert photons into current at wavelengths up to 850 nm, so further investigation to improve the cell performance is deserved.
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•A π-extended BODIPY dye 1 containing triphenylamine and nitrothiophene units was synthesized for the first time.•The dye 1 showed an intense absorption band at 730 nm with a molar extinction coefficient of 7.14 × 104 M−1 cm−1. .•The EQE measurement showed that a 1-loaded p-type DSSC devices convert photons into current at wavelengths up to 850 nm.
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 (
U
total
/
U
slip
).
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•We made transparent bulk composites using silica with ionic liquid or silicone oil.•Both composites we produced exhibited excellent water shedding property.•The ionic liquid ...composite was hydrophilic, but water-immiscible by hydrophobicity.•The hydrogen bond contribution was inferred from surface energy components.•Both composites exhibited good reconnection performance of the broken part.
We prepared transparent solid–liquid bulk composites by hybridizing porous silica with either an ionic liquid or a silicone oil, and investigated the reasons underlying the characteristic wetting behavior of the composite with the ionic liquid. The composite with the ionic liquid was hydrophilic, but it was immiscible in water, probably because of the hydrophobic effect. The contribution from the hydrogen bond component of the ionic liquid to the hydrophilicity was inferred from the division of surface energy components. The composite with the silicone oil was hydrophobic. Both composites exhibited small sliding angles and contact angle hysteresis on a water droplet. Spreading coefficients suggest that ionic liquid spreads at the water–solid interface in the composite. These properties simultaneously provide a water-shedding property and hydrophilicity on the composite with the ionic liquid. Both composites exhibited re-connection performance of the broken part with retention of their water shedding property.
Dye-sensitized photoelectrochemical cells (DSPECs) composed of a new near-infrared BODIPY dye
D1
that is co-deposited with a ruthenium water oxidation catalyst
C1
have been fabricated. The devices at ...pH 7.2 showed an excellent Faradaic efficiency of H
2
production (65.8%) that was 5.4 times larger than that of a triphenylamine photosensitizer
D2
and
C1
-coadsorbed cell.
Photo-induced water splitting to hydrogen and oxygen was shown to occur in a DSPEC with a near-infrared dye
D1
.
Fibrous TiO.sub.2 layer was formed on a metal Ti plate by soaking it in a KOH solution and subsequently firing it in air at 600 °C for 2 h. Hydrophobic solid-liquid bulk composite (SLBC) was prepared ...by impregnation of a commercial silicone-based oil into the fibrous TiO.sub.2 layer after coating with fluoroalkylsilane. Based on the spreading coefficients from interface energies, the topmost solid surface of the SLBC was covered by the oil film when a water-glycerin mixture droplet was placed on the surface. The mixture droplets slid down the SLBC with acceleration. Particle image velocimetry (PIV) analysis revealed rolling and slipping modes in the sliding of the mixture droplets on the SLBC surface. During sliding, the coefficient of the viscous drag force was correlated with the velocity ratio (U.sub.total/U.sub.slip). Results suggest that the estimation of the internal fluidity of the liquid droplet was feasible to some degree by evaluating the coefficient during droplet sliding with constant acceleration on the SLBC surface.
Fibrous TiO
2
layer was formed on a metal Ti plate by soaking it in a KOH solution and subsequently firing it in air at 600 °C for 2 h. Hydrophobic solid–liquid bulk composite (SLBC) was prepared by ...impregnation of a commercial silicone-based oil into the fibrous TiO
2
layer after coating with fluoroalkylsilane. Based on the spreading coefficients from interface energies, the topmost solid surface of the SLBC was covered by the oil film when a water–glycerin mixture droplet was placed on the surface. The mixture droplets slid down the SLBC with acceleration. Particle image velocimetry (PIV) analysis revealed rolling and slipping modes in the sliding of the mixture droplets on the SLBC surface. During sliding, the coefficient of the viscous drag force was correlated with the velocity ratio (
U
total
/
U
slip
). Results suggest that the estimation of the internal fluidity of the liquid droplet was feasible to some degree by evaluating the coefficient during droplet sliding with constant acceleration on the SLBC surface.
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