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TeO2 single crystal has drawn much attention in recent years due to its excellent acousto‐optic (AO) performance in the field of spectral imaging and optical processing. The optical properties of TeO2 single crystal are critical for the fabrication of AO devices. To improve the optical properties of the TeO2 single crystal, Mn4+ ions were doped into the TeO2 lattice. Herein, bulk TeO2 single crystal and TeO2:0.02Mn4+ single crystal have been successfully grown by a Bridgman method. Compared with the TeO2 single crystal, a 30% transmittance increase was observed in the TeO2:0.02Mn4+ single crystal. Furthermore, the TeO2:0.02Mn4+ single crystal shows a smaller extinction coefficient (≤0.01) in the Vis–NIR region, indicating less optical loss. The bandgap energy of TeO2:0.02Mn4+ was broadened from 3.360 to 3.635 eV. In addition, TeO2:0.02Mn4+ single crystal exhibits a higher refractive index (about 2.244), which indicates that TeO2:0.02Mn4+ single crystal is a potential medium for high‐efficiency AO devices. [ABSTRACT FROM AUTHOR]

The anion mixing strategy and equivalent substitution of functional groups are two effective and controllable methods to improve the probability of obtaining noncentrosymmetric (NCS) structures and optimizing nonlinear optical (NLO) performance. Herein, Pb2Ga3F6(SeO3)2X3·2H2O (X = Cl and Br) are discovered via cation group substitution and introduction of oxyfluoride [GaF4O2] octahedra. They are also the first examples possessing two kinds of halogen atoms in the hexagonal tungsten oxide (HTO) family. Pb2Ga3F6(SeO3)2Cl3·2H2O and Pb2Ga3F6(SeO3)2Br3·2H2O are isostructural and crystalize in the noncentrosymmetric trigonal space group R32, and they feature a three dimensional (3D) framework with HTO-type [Ga3F6(SeO3)2]∞ layers linked by [Pb2Br3]∞ layers. Owing to the effective arrangement of chemical functional units, Pb2Ga3F6(SeO3)2X3·2H2O exhibit strong SHG responses of 4.0–4.5 × KH2PO4 (KDP) and short UV cut-off edges of <300 nm, which are two essential parameters for NLO practical applications. The other physical and chemical properties of title compounds were evaluated in this work using IR spectroscopy, thermal parameter measurements, and theoretical calculations. [ABSTRACT FROM AUTHOR]

A series of lithium niobate crystals co-doped with uranium and indium was successfully grown by the modified vertical Bridgman method for the first time. With increasing In3+ ion doping concentration, the segregation coefficient of uranium and indium progressively deviated from 1. The structural refinement indicated that uranium ions with high valence preferred to occupy the Nb sites in LN: In, U crystals. LN: In2.0, U0.6 achieved multi-wavelength holographic writing with diffraction efficiency comparable to commercial crystals LN:Fe0.3, demonstrating a response time that was four times shorter than LN:Fe0.3. XPS analysis was employed to investigate the valence states of In3+ ions in LN: In2.0, U0.6, in which uranium ions presented three valences of +4, +5 and +6. Furthermore, the 'real threshold concentration' of In3+ ions in LN: In, U was calculated using the Li-vacancy model, which is consistent with the results obtained from the experimental study of the OH− absorption spectrum. Discussions on the photorefractive centers in LN: In, U are also provided. This study not only demonstrates the impact of doping In3+ ions on the growth of LN:U crystals, but also offers new insights into the photorefractive properties of LN in the visible band. [ABSTRACT FROM AUTHOR]

Antibacterial RBS@Cu:ZnO nanoparticles (NPs) were prepared by decorating Cu-doped ZnO NPs with Roussin's black salt (RBS), a nitric oxide (NO) precursor. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) tests indicated that the RBS@Cu:ZnO NPs were particulate matter with crystal morphology and nanoscaled sizes. X-ray diffraction (XRD) patterns revealed the wurtzite crystal structure of the NPs. Under irradiation of 543 nm laser, the RBS@Cu:ZnO NPs released NO in a controllable manner due to the decomposition of RBS. Cu-doped ZnO with a Cu/Zn molar ratio of 5% showed antibacterial activity in response to ultraviolet and visible light by photocatalysis. The doping of Cu enhanced the visible light absorption of ZnO by reducing its band gap. The RBS@Cu:ZnO NPs exhibited high antibacterial activity originating from the synergistic bacterial inhibitory effects of Cu-doped ZnO and released NO under visible laser irradiation. More importantly, the antibacterial activity could be controlled by adjusting the power output of laser irradiation. The RBS@Cu:ZnO NPs are promising antibacterial agents with potential applications in biomedicine and pharmaceutics. [ABSTRACT FROM AUTHOR]

Cu/N co-doped TiO2 nanopowder was prepared with a facile sol–gel method. In the absence of stabilizing agents, the co-doped nanopowder with nanoscaled particle sizes was obtained. Doping didn't change the anatase crystal structure of TiO2. Cuprite Cu2Cl(OH)3 formed in the co-doped nanopowder. Based on ultraviolet–visible (UV–vis) spectroscopy and X-ray photoelectron spectroscopy (XPS) data, the mechanisms of significantly improved photocatalytic activity of the co-doped nanopowder were discussed. The antibacterial evaluation and cytotoxicity test suggested the nanopowder inhibited bacteria significantly under visible light and had ultralow cytotoxicity. This work provided a promising antibacterial agent with potential biomedical applications. [ABSTRACT FROM AUTHOR]

Exploring highly efficient and stable halide perovskite‐based materials for photocatalytic CO2 reduction is a great challenge due to their poor intrinsic instability. Coincidentally, mesoporous molecular sieves have received tremendous attention as adsorbents, catalysts, and catalyst carriers. Herein, lead‐free double perovskite of Cs2AgBiBr6 (CABB) nanocrystals are grown in situ in MCM‐48 mesoporous molecular sieve for photocatalytic CO2 reduction. A remarkable performance is achieved by the CABB@MCM‐48 composite, which far exceeds that of pristine CABB. The mechanism of the photocatalytic CO2 reduction reaction is systematically investigated by the combination of in situ diffuse reflectance infrared Fourier transform spectra and density functional theory calculations. The result indicates that the molecular sieve can not only enhance the adsorption of CO2 molecules, but also promote the CO2 activation by reducing the energy barriers. This study provides some new insights into the design of excellent perovskite/molecular sieve‐based catalysts for solar fuel applications. [ABSTRACT FROM AUTHOR]