Facile construction of a robust CuS@NaNbO3 nanorod composite: A unique p-n heterojunction structure with superior performance in photocatalytic hydrogen evolution.

The construction of heterojunctions is commonly regarded as an efficient way to promote the production of hydrogen via photocatalytic water splitting through the enhancement of interfacial interactions. The p-n heterojunction is an important kind of heterojunction with an inner electric field based on the different properties of semiconductors. In this work, we reported the synthesis of a novel CuS/NaNbO3 p-n heterojunction by depositing CuS nanoparticles on the external surface of NaNbO3 nanorods, using a facile calcination and hydrothermal method. Through the screening of different ratios, the optimum hydrogen production activity reached 1603 µmol·g-1·h-1, which is much higher than that of NaNbO3 (3.6 times) and CuS (2.7 times). Subsequent characterizations proved semiconductor properties and the existence of p-n heterojunction interactions between the two materials, which inhibited the recombination of photogenerated carriers and improved the efficiency of electron transfer. This work provides a meaningful strategy to utilize the p-n heterojunction structure for the promotion of photocatalytic hydrogen production.

High-Efficiency, 80 mm Aperture Metalens Telescope.

Metalenses promise potential for a paradigm shift of conventional optical devices. However, the aperture sizes of metalenses are usually bound within hundreds of micrometers by the commonly used fabrication methods, limiting their usage on practical optical devices like telescopes. Here, for the first time, we demonstrate a high-efficiency, single-lens, refractive metalens telescope. We developed a mass production-friendly workflow for fabricating wafer-scale (80 mm aperture) metalenses using deep-ultraviolet (DUV) photolithography. Our metalens works in the near-infrared region with nearly diffraction-limited focal spot sizes and a high peak focusing efficiency of 80.84% at 1450 nm experimentally. Based on the metalens, we built a single-lens telescope and acquired images of the lunar surface, revealing its geographical structures. We believe our demonstration of the metalens telescope proves the exciting potential lying in the metasurfaces and could bring new possibilities for areas involving large optical systems, including geosciences, planetary observation, and astrophysical science.

Robust S-scheme hierarchical Au-ZnIn2S4/NaTaO3: Facile synthesis, superior photocatalytic H2 production and its charge transfer mechanism.

Designing Step-scheme (S-scheme) heterojunction with the directional charge transfer pathway has been considered as a promising strategy for realizing effective spatial separation of photo-generated carriers in a photocatalytic system by utilizing broadband solar energy. Herein, the novel and ternary S-scheme heterojunction photocatalysts were fabricated by embedding Au nanoparticles (NPs) on the surface of ZnIn2S4/NaTaO3 composites through a facile two-step hydrothermal method for the first time. As expected, it showed an enhanced hydrogen evolution rate of 11404 µmol g-1 h-1, which was approximately 58 and 10 times higher than that of the pristine NaTaO3 nanocubes (197 µmol g-1 h-1) and ZnIn2S4 microspheres (1180 µmol g-1 h-1) under simulated sunlight irradiation, respectively. An intimate heterojunction interface as well as Au nanoparticles as electron reservoir and reactive sites, which enhanced light absorption capacity and accelerated charge carrier separation, was answerable to the huge promotion in the photocatalytic performance. Most notably, XPS, EPR analysis and density functional theory (DFT) calculation results, revealed that the presence of strong interfacial electric fields promoted superior separation efficiency in the Au-ZnIn2S4/NaTaO3 S-scheme heterojunction. This innovative work may shed light on a more appealing and meaningful approach to modify sodium tantalate for the promising application in photocatalytic hydrogen generation.

Embedding indium nitride at the interface of indium-oxide/indium-zinc-sulfide heterostructure with enhanced interfacial charge transfer for high photocatalytic hydrogen evolution.

Enhancing the interfacial charge carriers transfer efficiency is important for designing photocatalysts with excellent hydrogen evolution performance. In this work, we have successfully constructed a In2O3@InN/ZnIn2S4 ternary heterostructure by embedding InN at the interface of thin-layered ZnIn2S4 and tubular In2O3 derived from metal-organic frameworks (MOFs) nanorods for the first time. The InN can not only adjust the energy band structure of In2O3, but also boost the photogenerated charge carriers transfer at the interface of In2O3 and ZnIn2S4. The optimum photocatalytic hydrogen evolution rate of In2O3@InN/ZnIn2S4 composite reaches 275 µmol/h (50 mg of catalyst) under simulated sunlight irradiation, which is obviously higher than pure In2O3 (12.5 times), ZnIn2S4 (2.5 times) and binary In2O3/ZnIn2S4 (1.8 times) photocatalysts. This work can offer a meaningful strategy to promote the interfacial charge separation in the heterostructure for excellent photocatalytic hydrogen evolution activity.

Chronic Effects of Foam Rolling on Flexibility and Performance: A Systematic Review of Randomized Controlled Trials.

The purpose of this study is to review the existing literature on chronic effects of foam rolling (FR) on flexibility and performance. Electronic databases were searched during January 2022 for topics related to FR. Included studies met the following criteria: (a) peer-reviewed articles written in English; (b) FR intervention of at least four weeks; (c) non-motorized FR device during intervention; (d) randomized controlled trial with existence of a control group; and (e) any lower body parameter related to flexibility, recovery, and performance. Nine studies met that criteria. Results revealed that chronic FR demonstrated conflicting results for improvement of flexibility. On the other hand, a majority of the articles in this review showed no beneficial effects of FR on performance. Lastly, the effect of FR on recovery is unclear. These findings suggest the need for further studies to establish the consensus about the long-term application of FR in flexibility, recovery, and performance.

Metasurface-Dressed Two-Dimensional on-Chip Waveguide for Free-Space Light Field Manipulation.

We show that a metasurface-coated two-dimensional (2D) slab waveguide enables the generation of arbitrary complex light fields by combining the extreme versatility and freedom on the wavefront control of optical metasurfaces with the compactness of photonic integrated circuits. We demonstrated off-chip 2D focusing and holographic projection with our metasurface-dressed photonic integrated devices. This technology holds the potential for many other optical applications requiring 2D light field manipulation with full on-chip integration, such as solid-state LiDAR and near-eye AR/VR displays.

SIproc: an open-source biomedical data processing platform for large hyperspectral images.

There has recently been significant interest within the vibrational spectroscopy community to apply quantitative spectroscopic imaging techniques to histology and clinical diagnosis. However, many of the proposed methods require collecting spectroscopic images that have a similar region size and resolution to the corresponding histological images. Since spectroscopic images contain significantly more spectral samples than traditional histology, the resulting data sets can approach hundreds of gigabytes to terabytes in size. This makes them difficult to store and process, and the tools available to researchers for handling large spectroscopic data sets are limited. Fundamental mathematical tools, such as MATLAB, Octave, and SciPy, are extremely powerful but require that the data be stored in fast memory. This memory limitation becomes impractical for even modestly sized histological images, which can be hundreds of gigabytes in size. In this paper, we propose an open-source toolkit designed to perform out-of-core processing of hyperspectral images. By taking advantage of graphical processing unit (GPU) computing combined with adaptive data streaming, our software alleviates common workstation memory limitations while achieving better performance than existing applications.

Emissive Pt(II) complexes bearing both cyclometalated ligand and 2-pyridyl hexafluoropropoxide ancillary chelate.

A new series of mono-cyclometalated Pt(II) complexes 1-4 with chelating 2-pyridyl hexafluoropropoxide as the ancillary ligand were synthesized. Single crystal X-ray diffraction studies were examined, giving evidence for the occurrence of pi pi stacking between the cyclometalated ligands, but a lack of intermolecular Pt ... Pt interaction. Among these complexes, the benzo[h]quinoline analogue 2a shows the greatest degree of pi pi stacking, which is also confirmed by the observation of additional, large Stokes shifted emission attributed to the aggregated counterparts in solid thin film. All these Pt(II) complexes are highly emissive in solid state, whereas except for 4-phenylquinazoline analogues 4a and 4b, complexes 1-3 in solution are subject to dominant radiationless deactivation induced, in part, by the solvent collision to the square planar Pt(II) framework. Electroluminescent OLEDs employing 2-phenylpyridine analogue 1b as the dopants were fabricated, rendering satisfactory performance data suited for future improvement.

An electron-transporting host material compatible with diverse triplet emitters used for highly efficient red- and green-electrophosphorescent devices.

A bifluorene analogue, T2N, containing a pyridyl moiety serves as both a host and an efficient electron-transporting material that is compatible with various heavy metal-containing red (Ir, Ru, Os, and Pt) and green (Ir) phosphors for highly efficient phosphorescent OLEDs possessing simple device architectures.

Pt(II) complexes with 6-(5-trifluoromethyl-pyrazol-3-yl)-2,2'-bipyridine terdentate chelating ligands: synthesis, characterization, and luminescent properties.

A series of Pt(II) complexes Pt(fpbpy)Cl (1), Pt(fpbpy)(OAc) (2), Pt(fpbpy)(NHCOMe) (3), Pt(fpbpy)(NHCOEt) (4), and [Pt(fpbpy)(NCMe)](BF(4)) (5) with deprotonated 6-(5-trifluoromethyl-pyrazol-3-yl)-2,2'-bipyridine terdentate ligand are prepared, among which 1 is converted to complexes 2-5 by a simple ligand substitution. Alternatively, acetamide complex 3 is prepared by hydrolysis of acetonitrile complex 5, while the back conversion from 3 to 1 is regulated by the addition of HCl solution, showing the reaction sequence 1-->5-->3-->1. Multilayer OLED devices are successfully fabricated by using triphenyl-(4-(9-phenyl-9H-fluoren-9-yl)phenyl) silane (TPSi-F) as host material and with doping concentrations of 1 varying from 7 to 100 %. The electroluminescence showed a substantial red-shifting versus the normal photoluminescence detected in solution. Moreover, at a doping concentration of 28 %, the device showed a saturated red luminescence with a maximum external quantum yield of 8.5 % at 20 mA cm(-2) and a peak luminescence of 47,543 cd m(-2) at 18.5 V.

Blue-emitting platinum(II) complexes bearing both pyridylpyrazolate chelate and bridging pyrazolate ligands: synthesis, structures, and photophysical properties.

A new Pt(II) dichloride complex [Pt(fppzH)Cl2] (1), in which fppzH = 3-(trifluoromethyl)-5-(2-pyridyl)pyrazole, was prepared by the treatment of a pyridylpyrazole chelate fppzH with K2PtCl4 in aqueous HCl solution. Complex 1 could further react with its parent pyrazole (pzH), 3,5-dimethylpyrazole (dmpzH), or 3,5-di-tert-butylpyrazole (dbpzH) to afford the monometallic [Pt(fppz)(pzH)Cl] (2), [Pt(fppz)(dmpzH)Cl] (3), [Pt(fppz)(dmpzH)2]Cl (4), or two structural isomers with formula [Pt(fppz)(dbpzH)Cl] (5a,b). Single-crystal X-ray diffraction studies of 2, 4, and 5a,b revealed a square planar Pt(II) framework, among which a strong interligand hydrogen bonding occurred between fppz and pzH ligands in 2. This interligand H-bonding is replaced by dual N-H...Cl interaction in 4 and both intermolecular N-H...O (with THF solvate) and N-H...Cl interaction in 5a,b, respectively; the latter are attributed to the bulky tert-butyl substituents that force the dbpzH ligand to adopt the perpendicular arrangement. Furthermore, complex 2 underwent rapid deprotonation in basic media to afford two isomeric complexes with formula [Pt(fppz)(mu-pz)]2 (6a,b), which are related to each other according to the spatial orientation of the fppz chelates, i.e., trans- and cis-isomerism. Similar reaction exerted on 3 afforded isomers 7a,b. Both 6a,b (7a,b) are essentially nonemissive in room-temperature fluid state but afford strong blue phosphorescence in solid state prepared via either vacuum-deposited thin film or 77 K CH2Cl2 matrix. As also supported by the computational approaches, the nature of emission has been assigned to be ligand-centered triplet pipi* mixed with certain metal-to-ligand charge-transfer character.

Luminescent platinum(II) complexes containing isoquinolinyl indazolate ligands: synthetic reaction pathway and photophysical properties.

New Pt(II) dichloride complexes [Pt(1-iqdzH)Cl2] (2a) and [Pt(3-iqdzH)Cl2] (2b), in which idqzH = 1- or 3-isoquinolinyl indazole, were prepared by treatment of the corresponding indazoles with K2PtCl4 in aqueous HCl solution. Despite their nonemissive nature, these complexes could react with excess indazole, sodium picolinate, and 3-trifluoromethyl-5-(2-pyridyl) pyrazole [(fppz)H] to afford the respective a and b series of luminescent complexes [Pt(1-iqdz)(L/\X)] and [Pt(3-iqdz)(L/\X)], where L/\X = 1-iqdz (1a), 3-iqdz (1b), pic (3a, 3b), and fppz (4a, 4b). Single-crystal X-ray diffraction studies of 1b, 2a, and 3b revealed a planar molecular geometry without notable intermolecular Pt...Pt contact in the solid crystal, a result of the steric repulsion imposed by the bulky indazole fragments. For coordination complexes 1, 3, and 4, photoluminescence in degassed CH2Cl2 revealed high quantum efficiency and short radiative lifetimes in the range of several microseconds. As supported by the spectral feature, the associated radiation lifetimes, and a computational approach based on time-dependent density function theory (TD-DFT), the origin of the emission is attributed to a mixed 3MLCT/3pipi transition. The TD-DFT approach further confirmed that, except for the series 1 complexes, the HOMO of 3-iqdz complexes 3b and 4b is much less located at the central Pt(II) atom than the HOMO orbitals of the respective 1-iqdz complexes 3a and 4a, leading to a smaller degree of MLCT contribution. Consequently, there are a blue-shifted emission signal and an inferior emission quantum yield for the 3-iqdz derivatives. OLED devices with a multilayer configuration of ITO/NPB/CBP:3a/BCP/Alq3/LiF/Al were fabricated using a CBP layer doped with various concentrations of 3a, ranging from 6% to 100%, within the emitting layer. The best device performance was realized using a 6% doping concentration, for which the external quantum yield of 4.93%, luminous efficiency of 12.19 cd/A, and power efficiency of 6.12 lm W-1 were observed at 20 mA/cm2, while a maximum luminescence as high as 20296 cd/m2 was also realized at 16 V, showing good prospect for the fabrication of Pt(II) based OLEDs.

Platinum(II) complexes with pyridyl azolate-based chelates: synthesis, structural characterization, and tuning of photo- and electrophosphorescence.

A new series of luminescent platinum(II) azolate complexes with a formula of [Pt(NwedgeN)(2)], in which NwedgeN = mppz (1), bppz (2a), bzpz (2b), bmpz (2c), bqpz (2d), fppz (3a), hppz (3b), bptz (4), hptz (5), were synthesized, and their photophyscial properties were examined. Single-crystal X-ray diffraction studies of 2c and 3b revealed a planar molecular geometry, in which the NwedgeN chelates adopt a trans configuration and show notable interligand C-H...N hydrogen bonding within the complex. Interesting intermolecular interactions were observed in the solid state. Complex 2c formed a slipped-stack structure with a Pt...Pt separation distance of 6.432 Angstroms, while complex 3b showed a columnar stacking with the molecules oriented in an alternating order in relation to the chain axis, giving a much reduced Pt...Pt distance of 3.442 Angstroms. The lowest absorption band for all complexes revealed strong state mixings between the singlet and triplet (MLCT and intraligand pipi) manifolds. Complexes 1 and 2 showed mixed (3)MLCT and (3)pipi phosphorescence in fluid solution. While radiationless deactivation was apparently dominant for complexes 3-5 in solution, resulting in rather weak emission, strong phosphorescence was observed in the room-temperature solid state with the peak wavelength being significantly red shifted compared to that in solution. The emission nature has been tentatively assigned to be (3)MMLCT in character. OLED devices with a multilayer configuration of ITO/NPB/CBP:2a/BCP/Alq(3)/LiF/Al were successfully fabricated using a CBP layer doped with various amount of 2a, ranging from 6 to 100%, as the emitting layer. A substantial red shift with increasing doping concentrations was observed in electroluminescence. With a neat film of 2a, the device showed a green emission with lambda(max) at 556 nm and an external QE of approximately 1.6% at a driving current of 20 mA. Similarly, for the device using a neat film of 3a, an electroluminescence centered at 616 nm with a slightly reduced external QE of approximately 2.1% was recorded. Aggregation of platinum(II) complexes in the solid state was proposed to account for the large red-shift in electroluminescence.