Multichannel Single-Photon Emissions with On-Demand Momentums by Using Anisotropic Quantum Metasurfaces.

Photon momentums and their control are important for carrying quantum information and increasing information capacities. It is a great challenge to freely control multiple momentums of single photons based on only phase-dependent schemes in isotropic metasurfaces because exact manipulations of interference phases and precise alignments between quantum emitters and metasurfaces are involved. Here, an anisotropic metasurface, in which anisotropic rather than isotropic nanoscatterers are arranged anisotropically, is proposed to freely control multiple momentums of single photons. In the metasurfaces, the phase-independent and phase-dependent schemes are used to independently control spin angular momentums (SAMs) and linear momentums (LMs), respectively. The phase-independent scheme allows robust alignment between quantum emitters and metasurfaces. The anisotropic design amends geometrical phases for oblique emissions, providing larger ranges (up to 53°) for tailoring LMs. In experiments, three-channel single-photon emissions with independent SAMs and LMs are demonstrated. The introduction of anisotropic nanoscatterers and anisotropic arrangements of nanoscatterers is a more general design method for metasurfaces, and it could provide more flexibility to freely and efficiently tailor single-photon emissions.

Synthesis of Vanadium Doped Lanthanum Bismuthate Nanorods for Enhanced Photocatalytic Activity.

Vanadium doped lanthanum bismuthate nanorods with vanadium ratio of 1%, 3%, 5% and 10 wt.% were fabricated through the hydrothermal method using sodium orthovanadate as vanadium source. Vanadium doped lanthanum bismuthate nanorod products were analyzed by scanning electron microscopy, X-ray diffraction pattern and diffuse reflection spectrum. X-ray diffraction patterns show that vanadium in the vanadium doped lanthanum bismuthate nanorods exists as triclinic Bi23V4O44.5 and monoclinic LaVO4 phases. Scanning electron microscopy observations show that the size and micro-morphology of the vanadium doped products are closely relative to the vanadium mass ratio. The length of the vanadium doped nanorods decreases and the morphology changes from nanorods to irregular nanoparticles with increasing the vanadium mass ratio. Solid UV-vis diffuse reflectance measurement shows that the bandgap value of the doped lanthanum bismuthate nanorods is narrowed from 2.37 eV to 2.25 eV after the vanadium doping ratio is increased from 1% to 10%. The doped lanthanum bismuthate nanorods illustrate enhanced photocatalytic performance for methylene orange (MO) removal with the irradiation of sunlight. The catalytic performance for MO removal depends on the irradiation time, vanadium content and dosage of the nanorods. The doped lanthanum bismuthate nanorods with the vanadium mass ratio of 10% possess the best MO catalytic degradation performance.

A Review on Ternary Bismuthate Nanoscale Materials.

BACKGROUND: Bismuth-containing nanoscale materials exhibit great application potential in catalysts, optical devices, electron devices, photo-electric devices and sensors owing to their good catalytic, optical, electric, photoelectric and sensing performance. Special research interest has been devoted to ternary bismuthate nanoscale materials due to their special layered structure, large specific surface area, excellent optical, catalytic, electrical and electrochemical performance. Therefore, it is essential to synthesize novel ternary bismuthate nanoscale materials for practical application. METHODS: The article reviews the recent progress and patents on the ternary bismuthate nanoscale materials. The recent progress and patents on the synthesis and application of the ternary bismuthate nanoscale materials are discussed. The possible development direction of the ternary bismuthate nanoscale materials for the synthesis and application is also analyzed. RESULTS: The ternary bismuthate nanoscale materials including zinc bismuthate, copper bismuthate, barium bismuthate, silver bismuthate, sodium bismuthate, lanthanum bismuthate nanoscale materials can be synthesized by hydrothermal route, sol-gel route, solvothermal decomposition route and ionexchange method. The ternary bismuthate nanoscale materials exhibit great application promising in the fields of photocatalysts, sensors and batteries. CONCLUSION: Large-scale synthesis of ternary bismuthate nanoscale materials at low cost, doping and combination using different nanoscale materials are important research directions for future research.