There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

BiOCl single-crystalline nanosheets with exposed {001} and {010} facets were selectively synthesized via a facile hydrothermal route. The resulting BiOCl single-crystalline nanosheets with exposed {001} facets exhibited higher activity for direct semiconductor photoexcitation pollutant degradation under UV light, but the counterpart with exposed {010} facets possessed superior activity for indirect dye photosensitization degradation under visible light.

Synthesis and Facet-Dependent Photoreactivity of BiOCl Single-Crystalline Nanosheets

Synthesis, Luminescent Properties, and Biomedical Applications Shili Gai,†,‡ Chunxia Li,† Piaoping Yang,*,‡ and Jun Lin*,† †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China ‡Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin, 150001, P. R. China

Recent Progress in Rare Earth Micro/Nanocrystals: Soft Chemical Synthesis, Luminescent Properties, and Biomedical Applications

Heterogeneous photocatalysis that employs photo-excited semiconductor materials to reduce water and oxidize toxic pollutants upon solar light irradiation holds great prospects for renewable energy substitutes and environmental protection. To utilize solar light effectively, the quest for highly active photocatalysts working under visible light has always been the research focus. Layered BiOX (X = Cl, Br, I) are a kind of newly exploited efficient photocatalysts, and their light response can be tuned from UV to visible light range. The properties of semiconductors are dependent on their morphologies and compositions as well as structures, and this also offers the guidelines for design of highly-efficient photocatalysts. In this review, recent advances and emerging strategies in tailoring BiOX (X = Cl, Br, I) nanostructures to boost their photocatalytic properties are surveyed.

Engineering BiOX (X = Cl, Br, I) nanostructures for highly efficient photocatalytic applications

Progress in discovery and structural design of color conversion phosphors for LEDs

Bismuth oxychloride (BiOCl) sub-microcrystals with tunable morphologies from nanoflakes to hollow microspheres (HMSs) have been synthesized by hydrolyzing a hierarchical precursor (BiCl3) in a solution of water and ethanol with the addition of poly(vinylpyrrolidone) (PVP) and citric acid. The obtained BiOCl possessed sub-microcrystals from single crystals to polycrystals. The formation of the nestlike and hollow structure was found to be induced by citric acid and PVP. The crystal growth and morphology control of BiOCl were explored. Interestingly, citric acid was utilized both as a crystal-growth-inducing agent and a structure-directing agent. The morphology and compositional characteristics of BiOCl were investigated by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Raman, and UV–vis spectra. The photocatalytic activities of BiOCl with different structures have also been investigated by the degradation of Rhodamine-B (RhB) dye under ultraviolet light irradia...

BiOCl Sub-Microcrystals Induced by Citric Acid and Their High Photocatalytic Activities

An efficient red phosphor, BaMoO4:Pr3+, has been fabricated by a convenient solid-state method. A strong red emission centered at 643 nm corresponding to the 3P0→3F2 transition of Pr3+ is observed under 430–500 nm excitation. In addition, improvement of the intensity of the red emission has been achieved by adding an alkali chloride to the BaMoO4:Pr3+ phosphor samples, this being explained by a charge compensation mechanism. The influence of the sintering temperature on the luminescence properties of the phosphors is also discussed.

/pdf/synthesis-and-characterization-of-new-red-phosphors-for-h1get490cs.pdf

Synthesis and characterization of new red phosphors for white LED applications

Silicon is regarded as a promising next-generation anode material to replace carbon-based materials in lithium–ion batteries. However, the poor conductivity and dramatic volume changes of Si anode materials lead to their low initial coulombic efficiency and unsatisfactory cycling stability. Herein, highly crystalline B-doped porous Si (B-doped pSi) nanoplates were designed and prepared via the air-oxidation demagnesiation of Mg2Si from p-type Si wafers. Doping with B greatly decreased the resistance and surface oxidation compared to the raw materials, and the high-temperature synthetic process resulted in high crystallinity. As a result, the obtained material exhibits a high initial coulombic efficiency of 89% and a superior rate capability of 1107 mA h g−1 at 6.4 A g−1. Furthermore, the unique porous plate-like structure provides free space for the volumetric expansion of Si, which results in good cycling performance (reversible capacity of 1500 mA h g−1 at 2 A g−1 after 300 cycles) in the B-doped porous Si.

Boron-doped porous Si anode materials with high initial coulombic efficiency and long cycling stability

Hollow/flower-like BiOI microspheres have been prepared through a facile precipitation route in a water–ethanol mixed solution with the assistance of PVP and citric acid (CA) at low temperature (70 °C) The obtained products were characterized by a range of methods such as XRD, FESEM, TEM, UV-vis, DRS, PL and nitrogen sorption A three-stage growth mechanism of such hierarchical hollow/flower-like microstructures has been proposed by observing the XRD analysis and FESEM of the intermediate products at different reaction times Interestingly, the structure of BiOI from hollow to flower-like could be obtained by only adjusting the different amounts of reagents in the reaction system The photocatalytic activities of the hollow/flower-like microspheres were evaluated by the degradation of RhB under visible-light irradiation, compared with the nanoplate sample and P25 Although the hollow BiOI microspheres had a higher specific surface area, the flower-like BiOI microspheres exhibited much higher adsorption and photocatalytic activities than the former This controllable morphology method and particular properties of BiOI hierarchical microstructures could be used to synthesize bismuth-based semiconductors or other structure-controllable materials and to explore remarkable potential applications of their photocatalytic degradation ability

Controllable synthesis of hollow/flower-like BiOI microspheres and highly efficient adsorption and photocatalytic activity

A dual-emitting luminescent lanthanide/transition heterometal-organic frameworks of Eu/Zr-MOF was synthesized by incorporation of Eu 3+ ions into NH 2 -UiO-66 under microwave irradiation condition. The multiband fluorescence derived from the characteristic emission of Eu 3+ and linker-to-cluster (Eu- oxo or Zr- oxo) charge transfer (LCCT) transition was fabricated. By combination of the luminescent property with the intrinsic porosity and open sites of amine group to bind target analytes, the Eu/Zr-MOF exhibited small molecules-dependent luminescence enhancement and quench effects. Notably, a drastic enhancement of fluorescent at 465 nm induced by formaldehyde was observed. Thus, a ratiometric fluorescent sensing for formaldehyde was performed based on the intensity ratio of two emission bands at 465 and 615 nm for Eu/Zr-MOF. Under the excitation of 365 nm, the increase in intensity ratio of the two emission bands was nearly linearly proportional to the amount of formaldehyde. By this Eu/Zr - MOF sensor, the detection limit of formaldehyde was 0.2 mg/L. This sensing mechanism was ascribed to the binding interaction of free amino groups in Eu/Zr-MOF with the guest. An added electron transfer from amino group containing lone pair electrons to the positively charged formaldehyde leads to a drastic enhancement of luminescence at about 465 nm, while the characteristic emission of Eu 3+ at 615 nm enhances slightly. These studies demonstrate that the strategy of multiband emissive heterometal-MOFs can be served as a facile method to fabricate sensitive and specific fluorescent probes of polluting organic small molecules.

Xibin Yu

Papers

BiOCl Sub-Microcrystals Induced by Citric Acid and Their High Photocatalytic Activities

Synthesis and characterization of new red phosphors for white LED applications

Boron-doped porous Si anode materials with high initial coulombic efficiency and long cycling stability

Controllable synthesis of hollow/flower-like BiOI microspheres and highly efficient adsorption and photocatalytic activity

Dual-Emitting Fluorescence of Eu/Zr-MOF for Ratiometric Sensing Formaldehyde