Search

One of the least understood aspects of prion diseases is the structure of infectious prion protein aggregates. Here we report a high-resolution cryo-EM structure of amyloid fibrils formed by human prion protein with Y145Stop mutation that is associated with a familial prion disease. This structural insight allows us not only to explain previous biochemical findings, but also provides direct support for the conformational adaptability model of prion transmissibility barriers.

The electrochemical oxygen reduction reaction (ORR) provides a green route for decentralized H2 O2 synthesis, where a structure-selectivity relationship is pivotal for the control of a highly selective and active two-electron pathway. Here, we report the fabrication of a boron and nitrogen co-doped turbostratic carbon catalyst with tunable B-N-C configurations (CNB-ZIL) by the assistance of a zwitterionic liquid (ZIL) for electrochemical hydrogen peroxide production. Combined spectroscopic analysis reveals a fine tailored B-N moiety in CNB-ZIL, where interfacial B-N species in a homogeneous distribution tend to segregate into hexagonal boron nitride domains at higher pyrolysis temperatures. Based on the experimental observations, a correlation between the interfacial B-N moieties and HO2 - selectivity is established. The CNB-ZIL electrocatalysts with optimal interfacial B-N moieties exhibit a high HO2 - selectivity with small overpotentials in alkaline media, giving a HO2 - yield of ≈1787 mmol gcatalyst -1 h-1 at -1.4 V in a flow-cell reactor. ispartof: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION vol:61 issue:37 ispartof: location:Germany status: published

ispartof: JOURNAL OF CATALYSIS vol:407 pages:1-9 status: published

Surface charge pattern analysis on HVDC insulators is a difficult task, which requires a comprehensive understanding of the physical mechanisms of surface charging. This paper provides a review on surface charge patterns and related models published within the past 30 years. In addition, based on the field-dependent charging theory, the research differences of various surface charge patterns obtained by previous researchers are explained. Difficulties and future prospects in modeling of surface charging phenomenon are also discussed. This paper may be used as a reference for the analysis of charge accumulation patterns and it would be helpful to researchers to compare and understand charge accumulation results published by earlier researchers.

Photocatalytic method has been intensively explored for Cr(VI) reduction owing to its efficient and environmentally friendly natures. In order to obtain a high efficiency in practical application, efficient photocatalysts need to be developed. Here, ZnIn2S4/SnS2 with a three-dimensional (3D) heterostructure was prepared by a hydrothermal method and its photocatalytic performance in Cr(VI) reduction was investigated. When the mass ratio of SnS2 to ZnIn2S4 is 1:10, the ZnIn2S4/SnS2 composite exhibits the highest photocatalytic activity with 100% efficiency for Cr(VI) (50 mg/L) reduction within 70 min under visible-light irradiation, which is much higher than those of pure ZnIn2S4 and SnS2. The enhanced charge separation and the light absorption have been confirmed from the photoluminescence and UV-vis absorption spectra to be the two reasons for the increased activity towards photocatalytic Cr(VI) reduction. In addition, after three cycles of testing, no obvious degradation is observed with the 3D heterostructured ZnIn2S4/SnS2, which maintains a good photocatalytic stability.

Three dimensional microporous zeolites have attracted much attention in catalysis because of their large BET surface area and abundant pores. Herein, Ti-MCM-41 zeolites with different molar ratio of Si/Ti were synthesized, and the surface acidity and active sites were adjusted by the modification of basic-earth metal oxides, and noble metal nanoparticles. The photocatalytic activity and selectivity were evaluated by the reduction of CO2 to CH4 and CO. The results indicated that the efficiency and selectivity of CO2 photoreduction to CH4 of Ti-MCM-41 zeolites were 93 ppm g−1 h−1 and 29% in the ratio Si/Ti = 10 under keeping the zeolite structure, and which is much higher than that of P25 with the value of 24 ppm g−1 h−1 and 23%. When the surface of Ti-MCM-41 zeolites was modified by different basic-earth metal oxides, the photo-reduction activity of CO2 to CH4 increased about 1.5 times with MgO modification, and the selectivity of CO2 to CH4 improved to 42%. Moreover, the photoactivity and selectivity enhanced to 8835 ppm g−1 h−1 and 93% when the surface was further decorated by Pt nanoparticles, while the selectivity of CO2 to CO reached 94% when Pd was loaded. Our work reveal reasonably that adjusting the acidity and active site of the microporous zeolites is a highly efficient way to improve the photocatalytic efficiency of CO2 reduction.

Surface charging of spacers is one of the main factors restricting the industrialization of DC gas insulated lines (GILs). The effects of ion mobility, gas pressure and temperature on surface charge behavior are important issues to be clarified. In this paper, a selection method of ion mobility is reviewed and reconsidered. A multiphysics-coupled model considering ion mobility, species of ions, temperature, and gas pressure is investigated. A mathematical model of ion mobility under low and high electric fields is presented and the critical electric field strengths are calculated, based on the current density vs electric field strength. The results show that the two critical electric field strength have different characteristics with gas pressure and temperature. The ion mobility in SF 6 gas has a completely different calculation model in high electric field and low electric field, and these two ion mobilities are equal only at a specific temperature and gas pressure. This paper can provide a reference for the selection of ion mobility in DC GILs under conditions of temperature and pressure.

Sodium ion batteries (SIBs) have been extensively investigated as a promising alternative for lithium ion batteries (LIBs) owing to the readily available character of sodium, lower costs of battery systems, as well as a similar working mechanism to LIBs. However, this view turns out to be oversimplified; countless reviews especially in the last years contradict each other, and it is still a challenging task to design highly performing electrode materials for SIBs. Due to the larger radius of Na+, its lower covalent character, and the resulting changes in intercalation chemistry, sodium is far from being only the bigger relative of lithium, and the difference leads to altered loading curves, and the occurrence of a multiplicity of binding sites. An in-depth holistic understanding of the sodium storage mechanisms is needed to resolve the controversial discussions in the research community, ideally starting with unquestionable thermodynamic points. Here, taking a tutorial perspective, first the recent discussions on the storage mechanism of sodium in carbons are reviewed from an unorthodox viewpoint, namely addressing sodium uptake as a multifaceted adsorption process with an added electrochemical binding potential. This model is based on literature data. Afterward, challenges and perspectives revealed by such a model are discussed.

Amyotrophic lateral sclerosis and several other neurodegenerative diseases are associated with brain deposits of amyloid-like aggregates formed by the C-terminal fragments of TDP-43 that contain the low complexity domain of the protein. Here, we report the cryo-EM structure of amyloid formed from the entire TDP-43 low complexity domain in vitro at pH 4. This structure reveals single protofilament fibrils containing a large (139-residue), tightly packed core. While the C-terminal part of this core region is largely planar and characterized by a small proportion of hydrophobic amino acids, the N-terminal region contains numerous hydrophobic residues and has a non-planar backbone conformation, resulting in rugged surfaces of fibril ends. The structural features found in these fibrils differ from those previously found for fibrils generated from short protein fragments. The present atomic model for TDP-43 LCD fibrils provides insight into potential structural perturbations caused by phosphorylation and disease-related mutations., Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) patients have brain deposits with amyloid-like aggregates from large C-terminal fragments of the transactive response DNA-binding protein of 43 kDa (TDP-43). Here, the authors present the cryo-EM structure of amyloid fibrils generated from the complete C-terminal TDP-43 low complexity domain and they discuss the effects of disease-causing mutations and phosphorylation of specific Ser residues.

The photothermal catalysis has attracted much attention as a new catalytic method. Utilization of self-generated heat instead of external heating source is an ideal approach for improving the performance of catalysts. Herein, a novel urchin-like hollow TiO2 photothermal nano-catalyst with spatially separated Pt and RuO2 dual cocatalysts combine with carbon layer (denoted as RuO2/TiO2/Pt/C) is reported for catalytic hydrogen evolution under visible light irradiation. The photothermal catalytic performance of the as-prepared catalysts was evaluated in relation to structural characterizations and the thermal effect of the carbon layer. The sandwich nanostructure of carbon layer, Pt NPs and TiO2 layer effectively support and protect Pt NPs from agglomeration and deactivation of Pt active sites. The hot electrons generated from carbon layer can participate in the photocatalytic reaction. Furthermore, the enhanced visible light absorption performance of TiO2 is explained by narrowing the band gap due to a small amount of doping carbon and reducing the penetration-loss of light via constructing the hollow structure. As a result, the synergy between the spatially separated Pt/RuO2 NPs and the thermal effect with carbon layer greatly improve the catalytic performance of the TiO2-based catalyst for hydrogen production under visible light irradiation.

Prion diseases are neurodegenerative disorders that affect many mammalian species. Mammalian prion proteins (PrPs) can misfold into many different aggregates. However, only a small subpopulation of these structures is infectious. One of the major unresolved questions in prion research is identifying which specific structural features of these misfolded protein aggregates are important for prion infectivity in vivo. Previously, two types of proteinase K–resistant, self-propagating aggregates were generated from the recombinant mouse prion protein in the presence of identical cofactors. Although these two aggregates appear biochemically very similar, they have dramatically different biological properties, with one of them being highly infectious and the other one lacking any infectivity. Here, we used several MS-based structural methods, including hydrogen–deuterium exchange and hydroxyl radical footprinting, to gain insight into the nature of structural differences between these two PrP aggregate types. Our experiments revealed a number of specific differences in the structure of infectious and noninfectious aggregates, both at the level of the polypeptide backbone and quaternary packing arrangement. In particular, we observed that a high degree of order and stability of β-sheet structure within the entire region between residues ∼89 and 227 is a primary attribute of infectious PrP aggregates examined in this study. By contrast, noninfectious PrP aggregates are characterized by markedly less ordered structure up to residue ∼167. The structural constraints reported here should facilitate development of experimentally based high-resolution structural models of infectiosus mammalian prions.

Oil-soluble catalysts could be of special significance for reducing the viscosity of heavy crude oil, because of their good dispersion in crude oil and high catalytic efficiency toward aquathermolysis. Ferric oleate was synthesized and applied as catalyst in the aquathermolysis reaction of Shengli heavy oil. It was found that ferric oleate was more efficient for heavy oil cracking than Co and Ni oleates. Besides, it was superior to oleic acid and inorganic ferric nitrate and achieved the highest viscosity reduction rate of up to 86.1%. In addition, the changes in the components of Shengli heavy oil before and after aquathermolysis were investigated by elemental analysis, Fourier transform infrared spectrometry, and 1H nuclear magnetic resonance spectroscopy. Results indicated that ferric oleate contributed to a significant increase in the content of light components and decrease in the content of resin, N and S. The as-prepared ferric oleate showed good activity for reducing the viscosity and improving the quality of the heavy crude oil, showing promising application potential in aquathermolysis of heavy crude oil.

Constructing a 0D/2D heterojunction is an important way to ameliorate the charge separation for achieving efficient solar hydrogen production. In this study, zero-dimensional (0D) AgIn5S8 nanoparticles/two-dimensional (2D) layered ZnIn2S4 0D/2D heterojunction composite was designed and prepared via a facile two-step hydrothermal process. Anchoring the AgIn5S8 nanoparticles on the 2D layered ZnIn2S4 can shorten the charge-migration distance, provide abundant active sites and extend the visible-light absorption. Benefiting from those favorable properties, the AgIn5S8/ZnIn2S4 0D/2D heterojunction composite exhibits the highest H2 evolution rate of 949.9 μmol g−1 h−1 under visible light irradiation (λ > 420) when the weight ratio of AgIn5S8 to ZnIn2S4 is 30%, which is about 3.6 and 17.6 times higher than pure ZnIn2S4 and AgIn5S8, respectively. Photoluminescence (PL) and photocurrent response results indicate that the improved charge separation efficiency is a critical reason for the enhanced H2 evolution activity. This study suggests that constructing a 0D/2D heterojunction can provide an efficient way to improve the photocatalytic performance of semiconductor photocatalysts for solar hydrogen production.

Exploiting an efficient and noble-metal-free cocatalyst is highly desired for photocatalytic H2 evolution from water. Here, we synthesized the MoS2-RGO/ZnO composite photocatalysts via a facile two-step solvothermal process. Through optimizing of the MoS2 and reduced graphene oxide (RGO) cocatalyst component proportion, the 0.75 wt%5G95 M/ZnO composite photocatalyst shows the highest H2 production rate of 288.4 μmol g−1 h−1 when the amount of MoS2-RGO is 0.75 wt% and the weight ratio of RGO to MoS2 is 5:95, which is about 14.1 times higher than the pure ZnO. More importantly, the ternary MoS2-RGO/ZnO composite photocatalyst exhibits much higher H2 evolution activity than the Pt loaded ZnO under the same condition. The significant improvement in the H2 evolution activity is ascribed to the positive synergetic effect between MoS2 and RGO, which acts as a hydrogen evolution cocatalyst and a robust electron transport pathway, respectively. This study suggests that MoS2-RGO can serves as an efficient and noble-metal-free cocatalyst to improve the H2 production performance of ZnO by suppressing the electron-hole pairs recombination.

Developing an efficient dye-sensitized photocatalyst for photocatalytic H2 evolution from water is highly desired. In this study, a novel ternary g-C3N4/Pt/GO composite was synthesized via a facile liquid-phase sonochemical approach. Pt nanoparticles were firstly deposited on the surfaces and/or interlayer of g-C3N4 by chemical reduction, and then, GO was penetrated through ultrasonic treatment. This preparation method is facilitated to prohibit the agglomeration of g-C3N4 and GO because of their π–π stacking interaction and enhance electrons transport and the adsorption of dye molecules. The Eosin Y-sensitized ternary g-C3N4/Pt/GO composite shows the highest H2 production rate of 3.82 mmol·g−1·h−1 under the optimization conditions, which about 2.1 times and 7.7 times higher than the Eosin Y-sensitized binary g-C3N4/Pt and GO/Pt photocatalysts, respectively. The improved charge separation efficiency is the main reason for the enhancement in H2 evolution activity. The apparent quantum efficiency of hydrogen evolution for the Eosin Y-sensitized ternary g-C3N4/Pt/GO composite is up to 9.7% at 420 nm. Moreover, the sensitized g-C3N4/Pt/GO composite shows stable photocatalytic activity for H2 evolution under visible light irradiation. The effect of pH, g-C3N4/GO weight ratios, Pt loading amounts, dye concentrations, and different type dyes on the H2 evolution activity was also investigated in detail.

Z-scheme g-C3N4-TiO2 heterojunctions containing g-C3N4 nanosheets with different thickness were prepared by sintering the mixture of g-C3N4 and nanotube titanic acid (denoted as NTA) at different temperatures in air. As-prepared Z-scheme g-C3N4-TiO2 heterojunctions were characterized by X-ray diffraction, transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible light diffuse reflectance spectrometry, electron spin resonance, and photoluminescence spectrometry. Findings indicate that the annealing temperature has crucial effects on the visible-light photocatalytic activity (λ ≥ 420 nm) of the as-prepared Z-scheme g-C3N4-TiO2 heterojunctions. The Ti3+ and porous g-C3N4 nanosheets formed upon the calcination at 600 °C as well as the low concentration of bulk single-electron trapped oxygen vacancy are favorable to the transport of the photoexcited charge carriers. This, in association with the Z-scheme system, contributes to improving the photocatalytic activity of g-C3N4-TiO2 photocatalysts. As a result, g-C3N4-TiO2 photocatalyst prepared at 600 °C exhibits good photocatalytic activity towards the degradation of propylene and hydrogen generation by water-splitting under visible light irradiation.

Four kinds of nanosilica-supported metallic and metatitanic acid nanocatalysts were synthesised as potential phase transfer catalysts for enhancing heavy oil recovery via a liquid-reduction method. The catalysts were carried by water and transferred into oil phase, and the catalytic performance of catalysts for the aquathermolysis reaction and viscosity reduction of the extra-heavy oil recovered at Shengli Oilfield (Dongying, China) was investigated. At a mass fraction of 1%, an aquathermolysis reaction temperature of 150°C and an aquathermolysis time of 36 h, the as-synthesised silica/zero valence iron and nickel (denoted as SiO2/Fe/Ni) catalyst was able to reduce the apparent viscosity of the two kinds of heavy oils by 79.3 and 77.6%, showing promising application in the industrial production of heavy crude oil.

Oxygen vacancies play an important role in many photocatalytic reaction, and have attracted enormous attention from the scientists and engineers. The surface or bulk oxygen vacancies have a different function in the photo-reaction process. Herein, three different TiO2 nanoparticles possessing surface oxygen vacancies (SO) and/or bulk single-electron-trapped oxygen vacancy (SETOV) were fabricated by dehydration or reduction of different titania precursors. The three kinds of TiO2 nanoparticles were characterized systematically by XRD, TEM, Raman, XPS, ESR, TG, UV–vis DRS, and PL techniques. The photocatalytic reduction results of CO2 indicated that both the bulk SETOVs and surface oxygen vacancies contributed to the enhancement of the light absorption, while the surface vacancies facilitated to the separation of the photo-generated charge carriers, and on the contrast, the bulk SETOVs acted as the recombination center. The co-existence of the surface and bulk oxygen vacancies exhibited a synergistic effect to improve the photoreduction efficiency of CO2 to CH4. Through adjusting the ratio of the surface and bulk oxygen vacancies and analyzing the positron lifetime and relative intensity by positron annihilation, the photoreduction efficiency of CO2 improved with the increase of the ratio of surface oxygen vacancies to bulk SETOVs.

Shape-dependent ultrafine anatase TiO 2 nanocrystals coexposed with (001) and (101) facets are synthesized in isopropanol by the simple solvothermal strategy. Nanotube titanic acid (NTA) was used as the Ti precursor, and hydrofluoric acid was the shape-control reagent. The nanotubular structure of NTA facilitated HF to adsorb on/into NTA, and made the shape-controlled process to be more economical and easier. The ratio of (001) facets of the obtained decahedral TiO 2 nanocrystals can be adjusted from 5 to 51%, and the mean diameter of nanoparticles is about 10–30 nm. The samples are characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscope, ultraviolet-visible diffuse reflectance spectrum, N 2 adsorption-desorption isotherms, fluorescence and Raman spectroscopy. The truncated octahedral bipyramid TiO 2 nanocrystals with 51% (001) and 49% (101) facets exposing showed the highest photoactivity for CO 2 reduction to CH 4 . This remarkable photocatalytic efficiency is attributed to the surface heterojunction between (001) and (101) crystal facets, the small size and large surface area of the truncated octahedral bipyramid TiO 2 nanocrystals.

Specific interactions between scaffold protein SH3 and multiple ankyrin repeat domains protein 3 (Shank3) and synapse-associated protein 90/postsynaptic density-95&ndash, associated protein (SAPAP) are essential for excitatory synapse development and plasticity. In a bunch of human neurological diseases, mutations on Shank3 or SAPAP are detected. To investigate the dynamical and thermodynamic properties of the specific binding between the N-terminal extended PDZ (Post-synaptic density-95/Discs large/Zonaoccludens-1) domain (N-PDZ) of Shank3 and the extended PDZ binding motif (E-PBM) of SAPAP, molecular dynamics simulation approaches were used to study the complex of N-PDZ with wild type and mutated E-PBM peptides. To compare with the experimental data, 974QTRL977 and 966IEIYI970 of E-PBM peptide were mutated to prolines to obtain the M4P and M5P system, respectively. Conformational analysis shows that the canonical PDZ domain is stable while the &beta, N extension presents high flexibility in all systems, especially for M5P. The high flexibility of &beta, N extension seems to set up a barrier for the non-specific binding in this area and provide the basis for specific molecular recognition between Shank3 and SAPAP. The wild type E-PBM tightly binds to N-PDZ during the simulation while loss of binding is observed in different segments of the mutated E-PBM peptides. Energy decomposition and hydrogen bonds analysis show that M4P mutations only disrupt the interactions with canonical PDZ domain, but the interactions with &beta, N1&prime, remain. In M5P system, although the interactions with &beta, are abolished, the binding between peptide and the canonical PDZ domain is not affected. The results indicate that the interactions in the two-binding site, the canonical PDZ domain and the &beta, extension, contribute to the binding between E-PBM and N-PDZ independently. The binding free energies calculated by MM/GBSA (Molecular Mechanics/Generalized Born Surface Area) are in agreement with the experimental binding affinities. Most of the residues on E-PBM contribute considerably favorable energies to the binding except A963 and D964 in the N-terminal. The study provides information to understand the molecular basis of specific binding between Shank3 and SAPAP, as well as clues for design of peptide inhibitors.

A theoretical model considering the dynamic change of surface charge accumulation in transient and steady states is proposed. The surface charge accumulation under transient and steady states are simulated using three model spacers with different volume conductivities. The results show that on the convex surface of a spacer, when the volume conductivity is lower than 2 × 10−18 S/m, the hetero-polarity charge accumulated on the spacer surface is dominant, while the homo-polarity charge accumulated on the surface is dominant when the conductivity is higher than 6 × 10−17 S/m. The surface charge density is non-uniformly distributed, and the time duration of the transient process of the surface charge density at different positions on the spacer surface is different, due to the distribution of electric field lines. It is hopefully that the content of this paper can provide reference for the mechanism study of gas-volume interface charge transport and the preparation of HVDC spacers.

Iron(II) phthalocyanine (FePc) is immobilized on graphene sheets to form a graphene(G)/iron(II) phthalocyanine hybrid (G/FePc) by the π–π stacking method. The resultant hybrids are characterized by UV–vis absorption spectra, FTIR, Raman spectra, BET, TEM, SEM and XRD. The result suggests that the interaction between graphene and FePc follows a donor-acceptor mode and the loading of FePc on graphene sheets not only facilitates the dispersion of FePc on graphene but also promotes the exfoliation of the graphene sheets. These samples are tested for photocatalytic degradation of phenol under visible light irradiation (λ ≥ 420 nm). And the photocatalytic activity of graphene, which is not presented when graphene individually acts on phenol, is greatly enhanced because of the π–π stacking interaction when FePc loaded on graphene. The G/FePc hybrid containing 25 wt.% FePc (G/FePc-0.25) exhibits the best photoactivity among the different loading content of FePc, whose degradation rate for phenol achieves 77.1% in the presence of H2O2 under visible light irradiation for 3 h.

The controlled modification of the inner and outer surfaces of hollow nanostructures with dual cocatalysts possessing redox ability is a key factor for improving the charge carrier separation efficiency and surface catalytic reaction efficiency of a catalyst. Herein, a novel hollow urchin-like TiO2 nanomaterial with Pt loaded on the inner surface and RuO2 on the outer surface is reported. The Pt acts as the electron capture centre and is responsible for the reduction reaction, whereas the RuO2 acts as the hole-trapping centre for the oxidation reaction. Compared to nanospheres, the urchin-like structures have a larger specific surface area. Moreover, the as-prepared TiO2 contained numerous single-electron oxygen vacancies (Vo·). The synergy between the highly dispersed catalytic material and spatially separated dual cocatalysts, characterised by hollow structures, a large specific surface area, and oxygen vacancies, greatly increased the activity of the catalyst. When Pt (0.5 wt%) is loaded on the inner surface of the nanomaterials, the hydrogen evolution rate is as high as 2045.1 μmolg−1h−1; moreover, it further improves to 3904.0 μmolg−1h−1 when RuO2 is loaded on the outer shell.

An economic and effective Pt-based alloy cocatalyst has attracted considerable attention due to their excellent catalytic activity and reducing Pt usage. In this study, PtNi alloy cocatalyst was successfully decorated on the g-C3N4/GO hybrid photocatalyst via a facile chemical reduction method. The Eosin Y-sensitized g-C3N4/PtNi/GO-0.5% composite photocatalyst yields about 1.54 and 1178 times higher hydrogen evolution rate than the Eosin Y-sensitized g-C3N4/Pt/GO-0.5% and g-C3N4/Ni/GO-0.5% samples, respectively. Mechanism of enhanced performance for the g-C3N4/PtNi/GO composite was also investigated by different characterization, such as photoluminescence, transient photocurrent response, and TEM. These results indicated that enhanced charge separation efficiency and more reactive sites are responsible for the improved hydrogen evolution performance due to the positive synergetic effect between Pt and Ni. This study suggests that PtNi alloy can be used as an economic and effective cocatalyst for hydrogen evolution reaction. Graphical abstractA significant enhancement of photocatalytic H2 evolution is realized over the Eosin Y-sensitized g-C3N4/PtNi/GO composite with PtNi alloy as an efficient cocatalyst.

An economic and effective Pt-based alloy cocatalyst has attracted considerable attention due to their excellent catalytic activity and reducing Pt usage. In this study, PtNi alloy cocatalyst was successfully decorated on the g-C3N4/GO hybrid photocatalyst via a facile chemical reduction method. The Eosin Y-sensitized g-C3N4/PtNi/GO-0.5% composite photocatalyst yields about 1.54 and 1178 times higher hydrogen evolution rate than the Eosin Y-sensitized g-C3N4/Pt/GO-0.5% and g-C3N4/Ni/GO-0.5% samples, respectively. Mechanism of enhanced performance for the g-C3N4/PtNi/GO composite was also investigated by different characterization, such as photoluminescence, transient photocurrent response, and TEM. These results indicated that enhanced charge separation efficiency and more reactive sites are responsible for the improved hydrogen evolution performance due to the positive synergetic effect between Pt and Ni. This study suggests that PtNi alloy can be used as an economic and effective cocatalyst for hydrogen evolution reaction. Graphical abstractA significant enhancement of photocatalytic H2 evolution is realized over the Eosin Y-sensitized g-C3N4/PtNi/GO composite with PtNi alloy as an efficient cocatalyst.

Nanotubular titanic acid (denoted as NTA) was calcined in air to generate TiO2 containing a large amount of single-electron-trapped oxygen vacancy (abridged as SETOV and denoted as V0 ). Resultant V0 self-modified (or self-doped) TiO2 (denoted as V0 –TiO2), visible light responsive but photocatalytically inactive under visible-light irradiation, was grafted with Fe(III) nanoclusters via an impregnation method to afford Fe(III)–V0 –TiO2 possessing visible-light phtocatalytic activity. The photocatalytic performance of as-prepared Fe(III)–V0 –TiO2 photocatalysts was evaluated and compared with that of N-doped TiO2, and the experimental results were further discussed based on density functional theory calculations. Results reveal that grafting Fe(III) leads to nearly no changes in the crystalline structure as well as morphology and grain size of V0 –TiO2 but results in good visible-light photocatalytic performance for the photodegradation of gaseous propylene under visible-light irradiation. This is because the grafted Fe(III) nanoclusters act as efficient electron trapping centers to significantly enhance the electron transfer from oxygen vacancy state and the conduction band of TiO2 to the adsorbed oxygen, thereby inducing the rapid separation of the photogenerated electrons and holes. Besides, the photocatalytic activity of Fe(III)–V0 –TiO2 photocatalysts is dependent on the dosage of grafted Fe(III), and it is critical to maintain a good matching between the energy level of V0 and surface-grafted Fe(III) cocatalyst so as to facilitate fast and efficient charge transfer. Thanks to the good availability, low cost, and nontoxicity, Fe as the cocatalyst could find promising applications in the development of high-performance photocatalysts.

Bi-doped TiO2 photocatalysts were prepared by a hydrothermal method using nanotube titanic acid as the Ti precursor. The samples were characterized by X-ray diffraction, transmission electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. Methyl orange (MO) was used as a model contaminant to evaluate the visible light photocatalytic activity of the Bi-doped TiO2 samples. We found that the Bi ions did not incorporate into the TiO2 lattice but instead existed in the form of BiOCl. The obtained BiOCl-composited TiO2 samples exhibited remarkable photocatalytic activity under visible light irradiation for the photodegradation of MO. The sample obtained when the Bi/Ti molar ratio was 1% and the hydrothermal treatment temperature was 130 °C (BTO-130-1) showed the highest photocatalytic activity. Moreover, a possible mechanism was proposed and the enhanced photocatalytic activity was discussed. The as-prepared catalyst also showed high photocatalytic activity for the photodegradation of 4-chlorophenol.

Chitosan-poly(vinyl alcohol)/bentonite (CTS-PVA/BT) nanocomposites with high adsorption selectivity for Hg(II) ions were synthesized by introducing BT into the CTS-PVA polymer matrix. The structure and morphology of the nanocomposites were characterized by XRD, FTIR and SEM, etc. The BT content has great influence on microstructure of the nanocomposites. BT is in the exfoliated state in the polymer matrix when the BT content is less than 7%. Whereas some of BT tends to be intercalated by CTS and an intercalate-exfoliated nanostructure is formed as the BT content is beyond 7%. Some of BT particles disperse as tactoids in the polymeric matrix and a flocculated-intercalated nanostructure is formed with further increasing the BT content. The nanocomposites possess a mesoporous structure with a narrow size distribution and BT can effectively enhance the thermal stability. The nanocomposites have high adsorption capacity and selectivity for Hg(II) ions. The adsorption capacities for Hg(II) ions with a BT content of 0%, 10%, 30% and 50% are 460.18, 455.12, 392.19 and 360.73. mg/g, respectively, which are much higher than that for Cu(II), Cd(II) and Pb(II) ions. Interestingly, BT can improve the adsorption selectivity of the nanocomposites for Hg(II) ions. In addition, the nanocomposites can effectively remove Hg(II) of different mercuric salts with various initial concentrations and pH.

The aim of this study was to investigate the effect of single- and multidose administration of the ethanol extract of danshen on in vivo CYP3A activity in healthy volunteers. A sequential, open-label, and three-period pharmacokinetic interaction study design was used based on 12 healthy male individuals. The plasma concentrations of midazolam and its metabolite 1-hydroxymidazolam were measured. Treatment with single dose of the extract caused the meanCmaxof midazolam to increase by 87% compared with control. After 10 days of the danshen extract intake, the mean AUC0–12,Cmax, andt1/2of midazolam were decreased by 79.9%, 66.6%, and 43.8%, respectively. The mean clearance of midazolam was increased by 501.6% compared with control. The in vitro study showed that dihydrotanshinone I in the extract could inhibit CYP3A, while tanshinone IIA and cryptotanshinone could induce CYP3A. In conclusion, a single-dose administration of the danshen extract can inhibit intestinal CYP3A, but multidose administration can induce intestinal and hepatic CYP3A.

Two kinds of one-dimensional (1D) nano-structured silver titanates, (Ag,H)2Ti4O9-nanowire (ATW) and (Ag,H)2Ti4O9-nanorod (ATR), were prepared by treating sodium titanate nanowires (STW) and titanic acid nanorods (TAR), respectively with molten AgNO3 through the ion-exchanged method. STW, TAR, ATW, and ATR all belong to the monoclinic crystallinity systems, and their band gaps are 3.6, 3.5, 2.8, and 2.8 eV, respectively. Interestingly, all of the four photocatalysts show strong and fast adsorption abilities for methylene blue (MB) and Alizarin Red S (ARS) dyes. MB and ARS can be adsorbed by the silver titanates completely within 5 and 10 min, respectively. The photocatalytic activities of the two kinds of silver titanates were evaluated by degradation of the MB and ARS dye solutions with high concentration, and by the decomposition of gaseous isopropyl alcohol (IPA) under visible light (λ ≥ 410 nm) irradiation. After the adsorption–desorption equilibrium, MB and ARS could be degradated almost completely within 60 and 80 min, respectively. In addition, the mineralization yield of IPA on ATW reached 80% after 6.5-h irradiation. The high photocatalytic activities of the silver titanates may be due to their large BET surface areas and strong adsorption abilities. Moreover, both of the silver titanates showed good stabilities in the long-time-run photocatalytic reactions.

Different-shaped one-dimensional (1D) titanic acid nanomaterials (TANs) were prepared by hydrothermal synthesis. By changing the reaction temperature (120, 170 and 200 °C), three kinds of 1D TAN, short-nanotubes (SNT), long-nanotubes (LNT), and nanorods (NR), were obtained. The obtained TANs were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), and solid-stated diffuse reflectance UV–vis spectra (UV–vis DRS) techniques. Based on these 1D TAN, Eosin Y-sensitized Pt-loaded TAN were prepared by the in situ impregnation and photo-reduction method. Their photocatalytic activity for hydrogen generation was evaluated in triethanolamine (TEOA) aqueous solution under visible light irradiation ( λ ≥ 420 nm). The results indicated that the morphology difference led to a significant variation of photocatalytic performance for hydrogen generation, with the activity order as follows: Eosin Y-sensitized Pt-loaded LNT > Eosin Y-sensitized Pt-loaded NR > Eosin Y-sensitized Pt-loaded SNT. The experimental conditions for photocatalytic hydrogen generation such as Pt loading content, the mass ratio of Eosin Y to TAN, and so on, were optimized. As a result, the highest apparent quantum yields of hydrogen generation for Eosin Y-sensitized Pt-loaded SNT, LNT, and NR were 6.65, 17.36, and 15.04%, respectively. The stability of these photocatalysts and the reaction mechanism of the photocatalytic hydrogen generation are also discussed in detail.