Influence of fluoride on f-f transitions of Eu in LiEuM2O8 (M=Mo, W)

The influence of fluoride on the luminescence of LiEuM₂O₈ (M=Mo, W) was studied. LiEuMo₂O₈ and LiEuW₂O₈ formed the whole range of solid solutions, which emitted intense red luminescence under the excitations by 395, 465 and 535 nm wavelengths. When doped with fluoride, the materials also formed solid solutions and the luminescent intensity was remarkably enhanced. The phosphor with optimized compositions in this system would be a promising red component for solid-state lighting devices based on GaN light-emitting diodes.     

The Effect of SiO2 Addition on the Grain Size and Photocatalytic Activity of TiO2 Thin Films

The uniform transparent TiO₂/SiO₂ nanometer composite thin films were prepared via sol-gel method on the soda lime glass substrates, and were characterized by X-ray photoelectron spectroscopy (XPS), FTIR spectroscopy, UV-VIS spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and BET surface areas. It was found that the addition of SiO₂ to TiO₂ thin films could suppress the grain growth of TiO₂ crystal and increase the hydroxyl content of the surface of TiO₂ films. The photocatalytic activity of the as-prepared TiO₂/SiO₂ composite thin films increases for SiO₂ content of less than 5 mol%.     

Low-temperature fabrication and photocatalytic activity of clustered TiO2 particles formed on glass fibers

Clustered anatase phase TiO₂ particles were uniformly formed on the surface of glass fibers by a liquid phase deposition (LPD) method at 60 °C using TiF₄ and H₃BO₃ as the precursors. The clustered TiO₂ particles deposited on the glass fibers and as a photocatalyst these particles not only have a larger surface area than TiO₂ thin films, but also can avoid the disadvantages of using TiO₂ powders encountered in air purification or water treatment. The photocatalytic activity of the sample was evaluated by the photocatalytic oxidation of nitrogen monoxide (NO) in the gaseous phase. The deposition conditions and chemical composition of the clustered TiO₂ particles were discussed. It was found that the clustered TiO₂ particles that formed on the glass fibers obviously showed photocatalytic activity without high-temperature calcination. A formation mechanism was proposed to account for the formation of TiO₂ clustered morphology on the glass fibers.     

Characterization of mesoporous nanocrystalline TiO2 photocatalysts synthesized via a sol-solvothermal process at a low temperature

Nanocrystalline TiO₂ samples with mesoporous structure were prepared via a solvothermal treatment of surfactant-stabilized TiO₂ sols. The samples were obtained from media of different acidities including nitric acid, deionized water, and ammonia (denoted as HT-1, HT-2 and HT-3, respectively). These samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N₂-sorption (BET surface area), micro-Raman spectroscopy, infrared absorption spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of the samples were tested by the self-photosensitized degradation of an azo dye, Mordant Yellow 10 (MY), in aqueous solution under visible light irradiation. The results reveal that all three samples have high surface area and are pure anatase phase. The sample prepared in nitric acid medium possesses the most ideal mesoporous structure and also exhibits a blue shift in the Raman spectrum. All three samples show much higher photocatalytic activity than the commercial P-25. The activity order of the three samples is HT-1>HT-2>HT-3.     

A simple and general method for the synthesis of multicomponent Na2V6O16.3H2O single-crystal nanobelts

Multicomponent Na2V6O16.3H2O (barnesite) single-crystalline nanobelts were synthesized by a direct reaction-crystallization growth of bulk V2O5 and NaF powders under hydrothermal treatment without using any templates or catalysts. This new strategy could be extended to prepare other one-dimensional multicomponent nanomaterials including ammonium, alkali-metal or alkali-earth metal vanadium oxide bronzes and other transition metal oxyfluorides. This is an efficient and mild solution method with clear advantages over the traditional high-temperature approach for the large-scale production of 1D multicomponent nanomaterials. The applicability of this approach toward the preparation of other inorganic systems, such as tungstates and molybdates, will be explored.     

A Renal‐Clearable Duplex Optical Reporter for Real‐Time Imaging of Contrast‐Induced Acute Kidney Injury

Despite its high morbidity and mortality, contrast‐induced acute kidney injury (CIAKI) remains a diagnostic dilemma because it relies on in vitro detection of insensitive late‐stage blood and urinary biomarkers. We report the synthesis of an activatable duplex reporter (ADR) for real‐time in vivo imaging of CIAKI. ADR is equipped with chemiluminescence and near‐infrared fluorescence (NIRF) signaling channels that can be activated by oxidative stress (superoxide anion, O₂^.?) and lysosomal damage (N‐acetyl‐β‐d ‐glucosaminidase, NAG), respectively. By virtue of its high renal clearance efficiency (80 % injected doses after 24 h injection), ADR detects sequential upregulation of O₂^.? and NAG in the kidneys of living mice prior to a significant decrease in glomerular filtration rate (GFR) and tissue damage in the course of CIAKI. ADR outperforms the typical clinical assays and detects CIAKI at least 8 h (NIRF) and up to 16 h (chemiluminescence) earlier.     

可见光铋系光催化剂的研究进展

当前工业发展导致了严重的能源和环境危机,光催化为这一难题提供了有效的解决方案.然而在实际应用中,传统氧化物光催化剂宽的带隙限制了它的可见光吸收,于是窄带隙光催化剂成为了研究的热点.其中铋系光催化剂以其高的可见光光催化活性引起了人们的广泛关注.因此本文介绍了铋系光催化剂的种类、制备、形貌、复合、性能等方面的研究现状,并展望了含铋可见光催化剂发展前景.     

Tailored Zwitterionic Hemicyanine Reporters for Early Diagnosis and Prognostic Assessment of Acute Renal Failure

Drug-induced renal failure (DIRF) poses a serious medical complication with high mortality risk. However, early diagnosis or prognosis of DIRF remain challenging, as current methods rely on detecting late-stage biomarkers. Herein we present a library of zwitterionic unimolecular hemicyanines (ZCs) available for constructing activatable reporters to detect DIRF since its initial stage. Zwitterionic properties of these probes are achieved through interspersedly integrating alkyl sulfonates and quaternary ammonium cations onto hemicyanine skeleton, which result in record low plasma protein binding (<5 %) and remarkable renal clearance efficiencies (≈96 %). An activatable reporter ZCRR is further developed by masking the optimal candidate ZC6 with a tetrapeptide specifically cleavable by caspase-8, an initiating indicator of apoptosis. In living mice with cisplatin-induced DIRF, systematically administered ZCRR efficiently accumulates in kidneys and responds to elevated caspase-8 for near-infrared fluorescence signals ‘turn-on’, enabling sensitive detection of intrarenal apoptosis 60 h earlier than clinical methods, and precise evaluation of apoptosis remediation effects by different medications on DIRF mice. As it's urinary excretable, ZCRR also allows for remote detection of DIRF and predicting renoprotective efficacy through in vitro optical urinalysis. This study thus presents unimolecular renal clearable scaffolds that are applicable to developing versatile activatable reporters for renal diseases management.     

Preparation and photocatalytic behavior of MoS2 and WS2 nanocluster sensitized TiO2

A new approach has been developed for the fabrication of visible light photocatalysts. Nanoclusters of MoS2 and WS2 are coupled to TiO2 by an in situ photoreduction deposition method taking advantage of the reducing power of the photogenerated electrons from TiO2 particles. The photocatalytic degradation of methylene blue and 4-chlorophenol in aqueous suspension has been employed to evaluate the visible light photocatalytic activity of the powders. The blue shift in the absorption onset confirms the size quantization of MS2 nanoclusters, which act as effective and stable sensitizers, making it possible to utilize visible light in photocatalysis. Quantum size effects alter the energy levels of the conduction and valence band edges in the coupled semiconductor systems, which favors the interparticle electron transfer. In addition, the coupled systems are believed to act in a cooperative manner by increasing the degree of charge carrier separation, which effectively reduces recombination.     

Facile fabrication and characterization of hierarchically porous calcium carbonate microspheres

Higher-order porous calcite microspheres exhibiting high specific surface areas, unusual morphologies and textures were fabricated by a simple precipitation reaction of CaCO3 in the presence of PSMA as a crystal modifier.