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Hydrogen peroxide (H2O2) photoproduction in seawater with metal-free photocatalysts derived from biomass materials is a green, sustainable, and ultra environmentally friendly way. However, most photocatalysts are always corroded or poisoned in seawater, resulting in a significantly reduced catalytic performance. Here, we report the metal-free photocatalysts (RUT-1 to RUT-5) with in-situ generated carbon dots (CDs) from biomass materials (Rutin) by a simple microwave-assisted pyrolysis method. Under visible light (λ ≥ 420 nm, 81.6 mW/cm2), the optimized catalyst of RUT-4 is stable and can achieve a high H2O2 yield of 330.36 µmol/L in seawater, 1.78 times higher than that in normal water. New transient potential scanning (TPS) tests are developed and operated to in-situ study the H2O2 photoproduction of RUT-4 under operation condition. RUT-4 has strong oxygen (O2) absorption capacity, and the O2 reduction rate in seawater is higher than that in water. Metal cations in seawater further promote the photo-charge separation and facilitate the photo-reduction reaction. For RUT-4, the conduction band level under operating conditions only satisfies the requirement of O2 reduction but not for hydrogen (H2) evolution. This work provides new insights for the in-situ study of photocatalyst under operation condition, and gives a green and sustainable path for the H2O2 photoproduction with metal-free catalysts in seawater. [ABSTRACT FROM AUTHOR]

Cerium‐based Metal‐Organic frameworks (Ce‐MOFs) are attracting increasing interest due to their similar structural features to zirconium MOFs. The redox behavior of Ce(III/IV) adds a range of properties to the compounds. Recently, perfluorinated linkers have been used in the synthesis of MOFs to introduce new characteristic into the structure. We report the synthesis and structural characterization of Ce(IV)‐based MOFs constructed using two perfluorinated alkyl linkers. Their structure, based on hexanuclear Ce6O4(OH)412+ clusters linked to each other by the dicarboxylate ions, has been solved ab‐initio from X‐ray powder diffraction data and refined by the Rietveld method. The crystallization kinetics and the MOF formation mechanism was also invesitigated by Synchrotron radiation with XAS spectroscopies (EXAFS and XANES). The MOFs present the same fcu cubic topology as observed in MOF‐801 and UiO‐66, and they showed good stability in water at different pH conditions. The electronic structure of these MOFs has been studied by DFT calculations in order to obtain insights into the density of states structure of the reported compounds, resulting in band gaps in the range of 2.8–3.1 eV. Their catalytic properties were tested both thermally and under visible light irradiation for the degradation of methyl orange (MO) dye. [ABSTRACT FROM AUTHOR]

Growth of Co film on SiO2/Si substrates with surface roughness of 0.5 nm and 1.6 nm have been studied in-situ using magneto-optical Kerr effect (MOKE) and transport measurements. In-situ measurements jointly suggest that the films grow via Volmer-Weber growth process and proceed via a nonmagnetic, superparamagnetic and a ferromagnetic phase formation on both the substrates. Islands are found to coalesce at film thicknesses ~ 0.6 nm and at ~ 1.5 nm with continuous film formation around film thickness ~1.5 nm and ~ 3.0 nm for smooth and rough substrates, respectively. Ferromagnetic long-range ordering i.e., appearance of magnetic hysteresis loop in both films is observed just after coalesce stage. Observed azimuthal angular dependence of coercivity confirmed the presence of a weak uniaxial magnetic anisotropy (UMA) in both the films, whereas difference in UMA with substrate roughness is interpreted in terms of combined effect of domain wall pinning and internal stresses in the films. Origin of much higher UMA in case of the Co film deposited on ripple patterned substrate of similar root mean square roughness is attributed to the modified long range dipolar stray fields on the surface.

Large-scale green tides in the Yellow Sea occurred for 13 consecutive years since 2007. The unusual co-occurrence of green tides and golden tides occurred in the Yellow Sea in 2017. The causative species are Ulva prolifera and/or Sargassum horneri. Previous studies on physiological response characteristics of U. prolifera and S. horneri are done in the laboratory mainly, and there is no in-situ comparative study in this regard. In this study, the in-situ physiological response characteristics of both species were measured. The results indicated that cyclic electron flow and antioxidant system play more important roles in protecting U. prolifera, while non-photochemical quenching is more important for adapting to the environment in S. horneri. U. prolifera has a stronger ability to utilize nutrients to rapidly increase its biomass under a suitable condition compared to S. horneri. [ABSTRACT FROM AUTHOR]

Dust explosion is short-lived, but dangerous. Time-resolved small angle X-ray scattering (SAXS) with synchrotron radiation is an effective method to study the microscopic dynamics of dust explosion, but it needs high beam flux, fast detector and appropriate explosion equipment. The pink beam SAXS beamline at the upcoming high energy photon source (HEPS in Beijing, China) will possess high beam flux as 1015 phs/s and equip new advanced fast integral detector, which will provide ideal conditions for time-resolved experiment. This study aims to preliminarily develop an explosion equipment to integrate into the SAXS instrument at HEPS in the early future. The main body of the equipment is a 20 L Siwek sphere (spherical shell) of stainless steel to serve as the chamber for dust explosion. The sphere has a pair of single crystal diamond windows that are used to horizontally pass synchrotron radiation X-rays with the beam path slightly below the centre of the sphere. The powder is sprayed from bottom into chamber of the sphere and ignited by the ignition rods extending from the top to the centre of the sphere. A corresponding control system is used to conveniently integrate and logically control the dust explosion and the corresponding SAXS signals collection. The feasibility and safety of the system have been verified at the 1W2B experimental station at the Beijing Synchrotron Radiation Facility (BSRF). [ABSTRACT FROM AUTHOR]

Organic-inorganic hybrid perovskites as promising light-harvesting materials have been the focus of scientific research and development of photovoltaics recently. Especially, metal halide perovskites currently become one of the most competitive candidates for the fabrication of solar cells with record certified efficiency over 25%. Despite the high efficiency, many fundamental questions remain unclear and need to be addressed at both the material and device levels, such as weaker stability, poorer reproducibility, easier degradation influenced by water, oxygen, thermal factors, and so on. Based on recent reports, interfacial engineering plays a crucial role in controlling the behavior of the charge carriers and in growing high quality, defect-free perovskite crystals, therefore helping to enhance device performance and operational stability. However, little attention has been paid to the interface interaction mechanism among carrier transport layers and perovskite active layer. It is extremely urgent to explore the perovskite interfaces in details and to find out how its interface structure is relative to the efficiency and hysteresis in perovskites solar cells. Based on the Shanghai Synchrotron Radiation Facility (SSRF), we have established an advanced perovskite photovoltaic device preparation and in-line test system, developed a series of unique surface diffraction analysis methods based on ex situ and in situ grazing incidence X-ray diffraction (GIXRD), and reported a large number of novel synchrotron radiation results on crystallization of the perovskite photovoltaics films. Our main investigations are aimed to deeply in-situ study the perovskite film growth dynamics using synchrotron radiation GIXRD technology in combination with a customized mini online glove box (c(H2O,O2)

Understanding the structure‐activity relationship of catalytic reactions at a molecular level still remains a great challenge. Herein, shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS) is employed to in‐situ study the catalytic hydrogenation of para‐nitrothiophenol (pNTP) on Pt‐based nanocatalysts with different size and composition. The nanocatalysts are assembled on pinhole‐free shell‐isolate nanoparticles (SHINs), which work as Raman amplifiers to enhance the Raman signals of species on the catalysts, allowing the in‐situ monitoring of catalytic reactions carried out on the catalysts. Using this strategy, we find that the catalytic activity of the Pt nanocatalysts shows a volcanic trend with the Pt size, and that PtM (M=Ni or Cu) bimetallic nanocatalysts display much higher performance compared with Pt due to better activation of the nitro group. This work demonstrates that SHINERS is a promising technique for in‐situ study of nanocatalysis thus can deepen the understanding of the behaviors of different catalysts. [ABSTRACT FROM AUTHOR]

Airflow disorder in inlet shafts and related crossheadings, caused by local natural ventilation pressure, is a complicated thermodynamic phenomenon. The conception of local natural ventilation pressure is proposed based on a simplified ventilation system. Airflow disorder principle is analyzed theoretically and verified by similar simulation experiment and in-situ study. Research results show that local natural ventilation pressure will form when average temperature difference or density difference of air-column exists among inlet shafts in an underground mine with exhaust ventilation. When changing in a large range, local natural ventilation pressure will cause airflow disorder in inlet shafts or related crossheadings. The research results have guiding significance for promoting the stability of ventilation system and improving the working environment of underground mines. [ABSTRACT FROM AUTHOR]

With the Pb doping content at Sr-site increasing, a series of Sr 1-x Pb x Li 2 Ti 6 O 14 (x = 0, 0.25, 0.50, 0.75, 1.0) are synthesized by a simple solid-state reaction. It is found that the reversible capacity and rate capability experience a parabolic course from SrLi 2 Ti 6 O 14 to PbLi 2 Ti 6 O 14 . Among all the as-prepared samples, Sr 0.5 Pb 0.5 Li 2 Ti 6 O 14 shows the best cycling and rate properties. It delivers an initial charge capacity of 163.2 mAh g −1 at 100 mA g −1 with the capacity retention of 96.08% after 100 cycles. In addition, it can also deliver a reversible capacity of 141.8 mAh g −1 at 700 mA g −1 . The superior electrochemical properties of Sr 0.5 Pb 0.5 Li 2 Ti 6 O 14 are attributed to the reduced charge transfer resistance and increased lithium-ion diffusion coefficient after doping. Besides, in-situ X-ray diffraction is also performed to investigate the lithium-ion insertion/extraction behaviors of SrLi 2 Ti 6 O 14 , Sr 0.5 Pb 0.5 Li 2 Ti 6 O 14 and PbLi 2 Ti 6 O 14 . The observed results confirm that Sr 0.5 Pb 0.5 Li 2 Ti 6 O 14 has good structural stability and reversibility for repeated lithium storage. [ABSTRACT FROM AUTHOR]

The formation of stereocomplex (SC) in enantiomeric poly(lactide)s via recrystallization of homocrystals was investigated by using simultaneous wide-angle and small-angle X-ray scattering. When the symmetric blend of poly( l -lactide) (PLLA) and poly( d -lactide) (PDLA) was heated from the glassy state at a slow heating rate (5 °C/min), predominant homocrystals were formed during heating (cold crystallization). Melting of homocrystals and crystallization of stereocomplex occurred almost simultaneously. In this case, the diffusion of PLLA and PDLA chains played an important role in determining the maximum attainable SC crystallinity. The crystallization behavior during annealing at different temperatures (185 °C, 195 °C and 225 °C) and subsequent cooling was further investigated to understand the effectiveness of annealing on the formation of stereocomplex. The stereocomplex content was unchanged during annealing at 185 °C and kept constant during cooling to room temperature. The SC crystallinity increased slightly during annealing at 195 °C and subsequently cooling. On the other hand, the content of SC increased during annealing at 225 °C and increased remarkably during cooling. A possible mechanism considering the diffusion of PLLA and PDLA chains was proposed. [ABSTRACT FROM AUTHOR]

Via Sr-site substitution, a series of Sr 0.95 M 0.05 Li 2 Ti 6 O 14 (M z+ = Na + , Cu 2+ , In 3+ ) are prepared as anode materials for lithium-ion batteries. It is found that the introduction of Na + , Cu 2+ or In 3+ into the crystal lattice can reduce the charge-transfer resistance and improve the lithium-ion diffusion coefficient of SrLi 2 Ti 6 O 14 . Especially for In 3+ -doping, it exhibits more obvious effect on these improvements. Furthermore, the substitution of Sr 2+ by In 3+ can also enhance the electronic conductivity via inducing a reduction of an equivalent number of Ti cations from Ti 4+ to Ti 3+ . As a result, Sr 0.95 In 0.05 Li 2 Ti 6 O 14 shows the best cycle and rate properties among all as-prepared samples. In addition, in-situ observation also proves that Sr 0.95 In 0.05 Li 2 Ti 6 O 14 is a zero-strain lithium storage compound during charge/discharge process. As a result, it delivers a lithium storage capacity of 136.4 mAh g −1 at 200 mA g −1 , 126.3 mAh g −1 at 400 mA g −1 and 121.0 mAh g −1 at 600 mA g −1 . In contrast, SrLi 2 Ti 6 O 14 only presents a charge capacity of 138.3 mAh g −1 at 200 mA g −1 , 120.3 mAh g −1 at 400 mA g −1 and 111.3 mAh g −1 at 600 mA g −1 . Therefore, In 3+ -doping is an effective method to enhance the electrochemical properties of SrLi 2 Ti 6 O 14 . [ABSTRACT FROM AUTHOR]

[Display omitted] • The present work describes a unique method to form the multilayer by combining oblique angle deposition (OAD) and normal angle deposition (NAD), to achieve strong magnetic anisotropy along with better high thermal stability in polycrystalline films. • Depositing several thin FeCo layers in between normally deposited FeCo layers, a strong uniaxial magnetic anisotropy (UMA) is produced in a thick FeCo multilayer structure; otherwise, FeCo is magnetically isotropic. • This method is applicable for any nanostructured magnetic material of polycrystalline or amorphous nature, where magnetocrystalline anisotropy is absent due to the absence of long-range structural order. • The present study provides a new method to produce a thin-film layered structure using single material with controlled morphology. This may have prominent implications for future technological devices, including optical devices or any kind of radiation absorbing devices where use of any single material is required, etc. Iron-Cobalt (FeCo) columnar, multilayered structure is prepared by depositing several thin FeCo layers by varying the angle between the surface normal and the evaporation direction as 0° (normal) and 60°(oblique), alternatively. In situ X-ray scattering and magneto-optical Kerr effect (MOKE) measurements established the evolution of magnetic properties with that of the morphology and structure of the multilayer. The strong shape anisotropy and compressive stress of nanocolumns in alternative FeCo layers resulted in a well-defined uniaxial magnetic anisotropy (UMA) with the easy axis of magnetization along the projection of the tilted nanocolumns in the film plane. The stress in the film provides minimization of magnetoelastic energy along the in-plane column direction, which couples with the columnar shape anisotropy energies and results in the preferential orientation of the magnetic easy axis along the oblique angle deposition direction in the film plane. Drastic reduction in the in-plane UMA after annealing at 450 °C is attributed to the merging of columns and removal of stresses after heat treatment. The present study opens a new pathway to produce magnetically anisotropic multilayer structures using single material and thus may have prominent implications for future technological devices. [ABSTRACT FROM AUTHOR]

In this study, the tensile behavior of Cr-coated zircaloy (Zr-4) for accident tolerant fuel claddings was investigated by in-situ observation and finite element (FE) analysis. The evolution of surface cracks in the Cr coating was experimentally observed, and the surface crack density was precisely predicted by the shear–lag model considering the effect of the residual stress. Moreover, the interfacial cracking behavior was numerically analyzed using the cohesive zone model. Finally, the interfacial fracture parameters of the coating system were evaluated based on the experimental results and FE calculations. The results exhibited that after the initiation, the surface crack density increased rapidly with the tensile strain, followed by a plateau stage under continuous tension. The fracture strength and interfacial shear strength of the Cr coating were evaluated as 382 MPa and 108 MPa, respectively. In addition, no interfacial spallation occurred under tension, indicating excellent interfacial adhesion properties of the Cr coating. However, a few short interfacial cracks were found to be initiated from the vertical crack tips, owing to the large local interfacial peeling and shear stresses. The FE analyses suggested that the lower limits of the interfacial fracture strength, σ 0 , and the fracture toughness, G c , of the Cr coating were in the range of 100 MPa–150 MPa and 100 J/m2–125 J/m2, respectively. Concurrently, σ 0 and G c for the entire Cr coating–Zr-4 substrate system were estimated to be generally large, i.e., above 250 MPa and 200 J/m2, respectively. • Detailed tensile cracking behavior of Cr coating was captured by in-situ observation. • Crack density evolution was precisely predicted by a modified shear-lag model. • Interfacial crack initiation and growth were predicted by the cohesive zone model. • Parameters of tensile strength, interfacial fracture strength and toughness were evaluated. [ABSTRACT FROM AUTHOR]