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A series of yellow-emitting La0.975−xGdxSr2AlO5:0.025Ce3+ phosphors have been synthesized by a solid-state reaction. All the samples retain the same tetragonal crystal structure, and the phosphors emit yellow emission with a peak maximum shifting from 540 nm to 556 nm, depending on the Gd/La ratio, when excited by 440 nm blue light. Their temperature dependent photoluminescence, fluorescence decay curves, and CIE values were also discussed. With increasing Gd/La ratio, the red-shift behaviors can be ascribed to the enhancing covalence, and the emission intensities first increased, then decreased, and finally increased to the maximum at x = 0.6. A white light-emitting diode (w-LED) lamp was fabricated based on the selected yellow-emitting La0.375Gd0.6Sr2AlO5:0.025Ce3+ phosphors combined with a 460 nm blue-emitting InGaN chip. The packaged w-LED lamp gave CIE chromaticity coordinates of (0.3562, 0.3660) with a warm color temperature of 4664 K and a color rendering index of 83. [ABSTRACT FROM AUTHOR]

Abstract: One dimensional rod shaped TiO2 nanostructures were successfully synthesized by a simple non-aqueous, alcoholysis based solvothermal process. Anatase TiO2 nanorods (TiO2 NRs) exhibited a surface area of 109.79m2/g with particle length and diameter of ~30–50nm and ~10–15nm (from SEM data), respectively. The photovoltaic performance of TiO2 nanorods based electrode was investigated in the dye-sensitized solar cell (DSSC). The device based on TiO2 NRs electrode exhibited an excellent short-circuit current density (J sc ) of 17.75mAcm−2 and an open-circuit voltage (V oc ) of 0.75V under 1Sun AM 1.5G solar light. Due to high dye loading, good light harvesting and fast electron transport, the optimal conversion efficiency (9.21%) of the DSSC fabricated from TiO2 NRs was significantly higher than that of the commercial DP-25 TiO2 nanoparticles based cell (6.43%). [Copyright &y& Elsevier]

Abstract: One dimensional TiO2 nanotube structure recently plays an important role in the application of dye sensitized solar cells (DSSCs) due to its faster electron transport. The fabrication of photoanode using the TiO2 nanotube structures mixed with the TiO2 nanoparticles was investigated to enhance the photovoltaic efficiency of DSSCs by increasing the surface area of electrode. In this work, self-organized and vertically-oriented TiO2 nanotube arrays (TNAs) covered with uniformly distributed TiO2 nanocubes (TNCs) were fabricated in a simple one-step anodization process. The X-ray diffraction patterns reveal that both TNAs and TNCs are in anatase phase. The scanning electron microscopy analysis demonstrates that the wall thickness and inner diameter of hexagonal close-packed TiO2 nanotubes from chemically polished Ti foils are 10–15 and 100–120nm, respectively, and the particle size of TNCs is 60–75nm. The DSSC fabricated by the mixed morphological TNAs with TNCs shows an enhanced photoconversion efficiency of ~63% than that of TNAs alone, due to the increase of both dye adsorption and electron transportation rate. [Copyright &y& Elsevier]

The funnel glass of the CRT monitor contains about 22–28% of lead oxide, of which lead is a highly toxic species and hazardous to the environment. This study proposes a process to form a protective layer of SiO2 film coating on the funnel glass to reduce the hazardous effect of lead leaching to the environment. The film coating benefits from the advantages of the sol–gel method. There are two key procedures of the stabilization technique, including the alkaline treatment and the formation of SiO2 coating from TEOS. The results show that the funnel glass powder treated with 10 M NaOH can produce a mushy layer on the surface. The mushy layer, which comprises OH− and water, can promote the formation of the SiO2 film layer on the surface of funnel glass powder. The conditions of the SiO2 film coating proposed in this study are: alkaline treatment by 10 M NaOH, the addition ratio of TEOS and funnel glass powder 2: 1, reaction temperature 40 °C, and reaction time 1.3 h. The EDS and ESCA results show that the Pb peak intensity on the surface of funnel glass decreases with the film coating. In the TCLP test, the leaching amount for Pb of the SiO2 film coated funnel glass powders is 0.7 mg/L, which is far lower than the standard in Taiwan EPA. Based on the experimental results, the formation mechanism of the SiO2 film layer on the surface of waste funnel glass powder is proposed. This study demonstrates that the SiO2 film coating is a potentially effective method to solve the problem of the waste funnel glass. [ABSTRACT FROM AUTHOR]

A molecular beam study of the Cl2+GaAs(s) reaction has been performed for surface temperatures in the range of 300–550 K. The gas phase neutral reaction products are identified by mass spectroscopy using electron bombardment ionization. Detailed analysis of the surface temperature dependence of the mass spectrum of the observed reaction products indicates that only three neutral reaction products are formed in this temperature range: GaCl3, AsCl3, and As4. At low (high) surface temperatures, only AsCl3 (As4) is observed. The ratio of the etching rates of Ga and As is independent of the surface temperature and within the range expected for stoichiometric etching. The change in the mode of As removal with surface temperature for the incident Cl2 flux implies that surface diffusion is important at surface temperatures above 400 K. [ABSTRACT FROM AUTHOR]

The controlled morphological TiO 2 particles have gained great importance in a wide variety of applications due to their promising physico-chemical properties. In this study, TiO 2 microstructures with various shapes to utilize as scattering layer in dye-sensitized solar cell (DSSC) applications were successfully synthesized via different hydrothermal conditions. The effects of the versatile preparation parameters including the amount of titania precursor and surfactant, the addition of ethanol/water, and the hydrothermal process temperature and time on the TiO 2 morphology were investigated. The structural and morphological analysis clearly shown that the preparation conditions played crucial roles in the morphology, particle size, and crystalline phase of the TiO 2 microparticles. Different kinds of shapes such as rice- (∼1.10 μm (l) and ∼0.41 μm (w)), star- (∼3.60 μm) and flower-like (3.75 μm) TiO 2 morphological structures were obtained. The morphology and size of the TiO 2 particles were mainly governed by the concentrations of titanium tetraisopropoxide (TTIP) precursor, amounts of tetramethylammonium hydroxide (TMAH) surfactant and hydrothermal temperatures and durations. The as-prepared rice-shaped TiO 2 was composed of mixed anatase and brookite binary phases, whereas the star- and flower-shaped TiO 2 microstructures were consisted of ternary anatase, rutile, and brookite crystalline TiO 2 phases. The three different rice-, star-, and flower-shaped TiO 2 microstructures were employed as scattering layers for photoanodes in DSSCs. Among them, the star-like TiO 2 photoanode based DSSC exhibited the highest power conversion efficiency of 9.56%, which was also better than those of the devices fabricated without scattering layer (a-TiO 2 , 8.38%) and with commercial P25 as scattering layer (a-TiO 2 /P25-TiO 2 , 8.52%) at the same film thickness of ∼14 μm. [ABSTRACT FROM AUTHOR]

Hole mobility is critical to the power conversion efficiencies of perovskite solar cells (PSCs). Organic small-molecule hole-transporting materials (HTMs) have attracted considerable interest in PSCs due to their structural flexibility and operational durability, but they suffer from modest hole mobility. On the other hand, inorganic HTMs with good hole mobility are inflexible in structural variation and exhibit unsatisfactory cell efficiency. In this study, a ligand BT28 and its zinc-based coordination complex BTZ30 were synthesized, characterized, and investigated as HTMs for PSC applications. The mixed-halide perovskites can be grown uniformly with large crystalline grains on both HTMs, which exhibit similar optical and electrochemical properties. However, it was discovered that the BTZ30-based solar cell exhibited an open-circuit voltage of 1.0817 V and a high short-circuit current density of 23.1392 mA cm -2 with a champion power conversion efficiency of close to 20 %. The performance difference between the two HTMs can be attributed to the difference in their hole mobilities, which is 63.31 % higher for BTZ30 than BT28. The comparison of non-metal and metal HTMs revealed the importance of considering hybrid structures to overcome some shortcomings associated with organic and inorganic HTMs and achieve high-performance PSCs., (© 2024 Wiley-VCH GmbH.)

Water splitting is promising, especially for energy and environmental applications; however, there are limited studies on the link between water splitting and cancer treatment. Upconversion nanoparticles (UCNPs) can be used to convert near-infrared (NIR) light to ultraviolet (UV) or visible (Vis) light and have great potential for biomedical applications because of their profound penetration ability, theranostic approaches, low self-fluorescence background, reduced damage to biological tissue, and low toxicity. UCNPs with photocatalytic materials can enhance the photocatalytic activities that generate a shorter wavelength to increase the tissue penetration depth in the biological microenvironment under NIR light irradiation. Moreover, UCNPs with a photosensitizer can absorb NIR light and convert it into UV/vis light and emit upconverted photons, which excite the photoinitiator to create H 2 , O 2 , and/or OH˙ via water splitting processes when exposed to NIR irradiation. Therefore, combining UCNPs with intensified photocatalytic and photoinitiator materials may be a promising therapeutic approach for cancer treatment. This review provides a novel strategy for explaining the principles and mechanisms of UCNPs and NIR-driven UCNPs with photocatalytic materials through water splitting to achieve therapeutic outcomes for clinical applications. Moreover, the challenges and future perspectives of UCNP-based photocatalytic materials for water splitting for cancer treatment are discussed in this review.

Hole transport materials (HTMs) with appropriate energy levels and comprehensive passivation effects help to obtain highly efficient and stable perovskite solar cells (PSCs). Electron-deficient character-induced HTMs can generate varying energy level alignments near the HTM/perovskite interface. Herein, we report the synthesis and investigation of two new dipolar HTMs, WWC103 and WWC105 , based on 2-(1,1-dicyanomethylene)rhodamine and 4-cynophenylacetonitrile acceptors, enabling high-efficiency mixed-cation mixed-halide perovskite solar cells. Apart from having different acceptors, these HTMs are built on a heterocyclic frame, which can provide passivation effects and improve the morphology of the perovskite layer. As a result, these dopant-free HTM-based solar cells show a high open-circuit voltage and good power conversion efficiency. Among both, the solar cell based on the HTM with 2-(1,1-dicyanomethylene)rhodamine exhibits a high open-circuit voltage of 1.09 V with a champion power conversion efficiency of over 20.51%. The improved performance of WWC103 over WWC105 (19.74%) is attributed to the new acceptor, which, in addition to providing good energy-level alignments and hole mobility, also holds the ability to passivate the defects. The findings suggest a new acceptor unit for constructing dopant-free HTMs for efficient PSCs.

Solar-driven water electrolysis to produce hydrogen is one of the clean energy options for the current energy-related challenges. Si as a photocathode exhibits a large overpotential due to the slow hydrogen evolution reaction (HER) kinetics and hence needs to be modified with a cocatalyst layer. MoS 2 is a poor HER cocatalyst due to its inert basal plane. Activation of the MoS 2 basal plane will facilitate HER kinetics. In this study, we have incorporated SnS 2 into MoS 2 ultrathin sheets to induce defect formation and phase transformation. MoS 2 /SnS 2 composite ultrathin sheets with a Sn 2+ state create a large number of S vacancies on the basal sites. The optimized defect-rich MoS 2 /SnS 2 ultrathin sheets decorated on surface-modified Si micro pyramids as photocathodes show a current density of -23.8 mA/cm 2 at 0 V with an onset potential of 0.23 V under acidic conditions, which is higher than that of the pristine MoS 2 . The incorporation of SnS 2 into 2H-MoS 2 ultrathin sheets not only induces a phase but also can alter the local atomic arrangement, which in turn is verified by their magnetic response. The diamagnetic SnS 2 phase causes a decrease in symmetry and an increase in magnetic anisotropy of the Mo 3+ ions.

Insulin, which is a hormone produced by the β-cells of the pancreas, regulates the glucose levels in the blood and can transport glucose into cells to produce glycogen or triglycerides. Insulin deficiency can lead to hyperglycemia and diabetes. Therefore, insulin detection is critical in clinical diagnosis. In this study, disposable Au electrodes were modified with copper(II) benzene-1,3,5-tricarboxylate (Cu-BTC)/leaf-like zeolitic imidazolate framework (ZIF-L) for insulin detection. The aptamers are easily immobilized on the Cu-BTC/ZIF-L composite by physical adsorption and facilitated the specific interaction between aptamers and insulin. The Cu-BTC/ZIF-L composite-based aptasensor presented a wide linear insulin detection range (0.1 pM to 5 μM) and a low limit of detection of 0.027 pM. In addition, the aptasensor displayed high specificity, good reproducibility and stability, and favorable practicability in human serum samples. For the in vivo tests, Cu-BTC/ZIF-L composite-modified electrodes were implanted in non-diabetic and diabetic mice, and insulin was quantified using electrochemical and enzyme-linked immunosorbent assay methods.

Metal-CO 2 rechargeable batteries are of great importance due to their higher energy density and carbon capture capability. In particular, Na-CO 2 batteries are potential energy-storage devices that can replace Li-based batteries due to their lower cost and abundance. However, because of the slow electrochemical processes owing to the carbonated discharge products, the cell shows a high overpotential. The charge overpotential of the Na-CO 2 battery increases because of the cathode catalyst's inability to break down the insulating discharge product Na 2 CO 3 , thereby resulting in poor cycle performance. Herein, we develop an ultrathin nanosheet MoS 2 /SnS 2 cathode composite catalyst for Na-CO 2 battery application. Insertion of SnS 2 reduces the overpotential and improves the cyclic stability compared to pristine MoS 2 . As shown by a cycle test with a restricted capacity of 500 mAh/g at 50 mA/g, the battery is stable up to 100 discharge-charge cycles as the prepared catalyst successfully decomposes Na 2 CO 3 . Furthermore, the battery with the MoS 2 /SnS 2 cathode catalyst has a discharge capacity of 35 889 mAh/g. The reasons for improvements in the cycle performance and overpotential of the MoS 2 /SnS 2 composite cathode catalyst are examined by a combination of Raman, X-ray photoelectron spectroscopy, and extended X-ray absorption fine structure analysis, which reveals an underneath phase transformation and changes in the local atomic environment to be responsible. SnS 2 incorporation induces S-vacancies in the basal plane and 1T character in 2H MoS 2 . This combined impact of SnS 2 incorporation results in undercoordinated Mo atoms. Such a change in the electronic structure and the phase of the MoS 2 /SnS 2 composite cathode catalyst results in higher catalytic activity and reduces the cell overpotential.

The use of red phosphors with low light-scattering loss could improve the luminous efficacy and color rendering of white-light-emitting diodes (LEDs). Thus, the discovery of such phosphors is highly desired. In this work, high-efficiency two-dimensional red-emitting K 2 TiF 6 :Mn 4+ (KTFM) were synthesized via an alcohol-assisted coprecipitation route. The synergistic effects of 1-propanol and hydrofluoric acid on the growth of KTFM microsheets (MSs) were studied through the first-principles calculations, which revealed that 1-propanol promoted the growth of KTFM MSs by preferentially adsorbing on the H-terminated K 2 TiF 6 (001) surface. The photoluminescence quantum efficiency (QE) of Mn 4+ -activated K 2 TiF 6 MSs was highly related to their size and thickness. The morphology-optimal KTFM MSs presented high internal QE (>90%), external QE (>71%), and thermal quenching temperature (102% at 150 °C relative to that at 25 °C). A prototype phosphor-converted LED with KTFM as the red-emitting component showed excellent color rendition ( R a = 91, R9 = 79) and high luminous efficacy (LE = 156 lm/w).

Narrow-band Mn 4+ -doped fluoride phosphors have become a research hotspot worldwide. In this study, we propose integrated surface modification processes to enhance the performance and stability of the luminescence properties of K 2 TiF 6 :Mn 4+ (KTF) phosphor. These integrated process are applied in the initial synthesis step, coating of the as-synthesized powder post-treatment process, and during the application of the phosphor in the white-light-emitting diode (WLED) device. Surface etching is conducted to remove impurities and small particles in KTF. Double-shell coating forms a stable protective layer outside the KTF. Atomic layer deposition is employed for the surface of the WLED device.

A new type of carbene-based ruthenium sensitizer, CB104, with a highly conjugated ancillary ligand, diphenylvinylthiophene-substituted benzimidazolepyridine, was designed and developed for dye-sensitized solar cell applications. The influence of the thiophene antenna on the performance of the cell anchored with CB104 was investigated. Compared with the dye CBTR, the conjugated thiophene in the ancillary ligand of CB104 enhanced the molar extinction coefficient of the intraligand π-π* transition and the intensity of the lower energy metal-to-ligand charge-transfer band. However, the incident photon-to-current conversion efficiency spectrum of the cell anchored with CB104 (0.15 mM) showed a maximum of 63 % at 420 nm. The cell sensitized with the dye CB104 attained a power conversion efficiency of 7.30 %, which was lower than that of the cell with nonconjugated sensitizer CBTR (8.92 %) under the same fabrication conditions. The variation in the performance of these two dyes demonstrated that elongating the conjugated light-harvesting antenna resulted in the reduction of short-circuit photocurrent density, which might have been due to the aggregation of dye molecules. In the presence of a coabsorbate, chenodeoxycholic acid, the CB104-sensitized cell exhibited an enhanced photocurrent density and achieved a photovoltaic efficiency of 8.36 %., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)