We prepared a new p–n heterojunction photocatalysts p-CuBi2O4/n-NaTaO3 by a simple grinding–annealing method. The photocatalysts showed high photocatalytic activity under visible-light irradiation. ...Display omitted
► A novel p–n heterojunction photocatalyst p-CuBi2O4/n-NaTaO3 was prepared. ► The photocatalyst was prepared by a simple and safe grinding–annealing method. ► High activity for the photodegradation of MB under visible light irradiation.
In this study, a series of p-CuBi2O4/n-NaTaO3 heteronanostructures were synthesized with the grinding–annealing method. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and UV–vis diffuse reflectance spectroscopy (DRS). The photocatalysts exhibit enhanced photocatalytic activity for methyl blue dye degradation under visible-light irradiation. The highest photocatalytic degradation efficiency was observed when the sample calcined at 500°C with 50wt.% CuBi2O4 content. On the basis of the calculated energy band positions, the mechanism of enhanced photocatalytic activity was discussed.
•AgI/Bi2WO6 was synthesized using a deposition–precipitation method.•AgI/Bi2WO6 displays better photocatalytic activity than AgI and Bi2WO6.•Good visible-light photocatalytic activity is based on ...electron–hole separation between AgI and Bi2WO6.
In this study, a series of AgI/Bi2WO6 heterojunction photocatalysts were synthesized with deposition–precipitation method. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), UV–vis diffuse reflectance spectroscopy (DRS). The photocatalysts exhibited enhanced photocatalytic activity on the RhB dye degradation under visible-light irradiation. The 58.5% AgI/Bi2WO6 sample was observed to have the highest photocatalytic degradation efficiency. Based on the calculated energy band positions, the mechanism of enhanced photocatalytic activity was discussed.
In this study, a series of AgI/Bi sub(2)WO sub(6) heterojunction photocatalysts were synthesized with deposition-precipitation method. The photocatalysts were characterized by X-ray diffraction ...(XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), UV-vis diffuse reflectance spectroscopy (DRS). The photocatalysts exhibited enhanced photocatalytic activity on the RhB dye degradation under visible-light irradiation. The 58.5% AgI/Bi sub(2)WO sub(6) sample was observed to have the highest photocatalytic degradation efficiency. Based on the calculated energy band positions, the mechanism of enhanced photocatalytic activity was discussed.
Paired electrosynthesis is a promising technology with the potential to generate value‐added products at both electrodes in a cost‐effective manner. Herein, 3D vanadium nitride (VN) and Pd/VN hollow ...nanospheres are successfully fabricated and coupled to carry out simultaneous electrocatalytic oxidation (ECO) and electrocatalytic hydrogenation (ECH) of 5‐hydroxymethylfurfural (HMF) into 2, 5‐furandicarboxylic acid (FDCA) and 2,5‐bishydroxymethyl‐tetrahydrofuran (DHMTHF), respectively. VN shows excellent ECO performance with high HMF conversion (≥98%), FDCA selectivity (≥96%), and faradaic efficiency (≥84%) after a stability test, and Pd/VN achieves high ECH selectivity for DHMTHF at ≥88% and an HMF conversion of ≥90%, with a faradaic efficiency of ≥86%. VN and Pd/VN incorporated into a membrane electrode assembly in a paired electrolysis system shows potential for large‐scale biomass conversion and upgrading. Theoretical calculations reveal that the higher performance of VN for the production of ECO can be attributed to its lower d‐band center level relative to the Fermi level compared to that of V2O5, which favors HMF chemisorption and activation. This study paves the way for developing paired electrosynthesis technologies with the potential for biomass utilization and energy conversion.
A paired electrolysis system is employed for simultaneous electrocatalytic oxidation of 5‐hydroxymethylfurfural to 2, 5‐furandicarboxylic acid and electrocatalytic hydrogenation to 2, 5‐bishydroxymethyl‐tetrahydrofuran using VN and Pd/VN as electrocatalysts with excellent activity. This strategy opens up a new avenue for biomass utilization and energy conversion.
To evaluate the effectiveness and safety of a cancer pain information platform combined with semi-implantable intrathecal drug delivery systems among the patients with refractory cancer pain under a ...“home analgesia” model. This was a retrospective study. A total of 49 patients underwent semi-implantable intrathecal drug delivery systems with patient-controlled analgesia in conjunction with the establishment of a cancer pain information platform. Numeric rating scales (NRS), Bruggrmann comfort scale (BCS), high-quality sleep duration, and opioid-related adverse effects were recorded at various time points and analyzed: the day on admission (T0), the day of discharge (T1), 30 days post-discharge (T2), 60 days post-discharge (T3), 90 days post-discharge (T4), 120 days post-discharge (T5), 150 days post-discharge (T6), 180 days post-discharge (T7), and the day before death (T8). Compared with T0, NRS significantly decreased and BCS significantly increased at T1 to T8 time points ( P < .05). However, NRS and BCS did not show differences at T1 to T8 time points ( P > .05). The duration of high-quality sleep was significantly extended, and the incidence of opioid-related adverse effects was significantly reduced. Postoperative complications included 1 case of cerebrospinal fluid leakage, 3 cases of infection at the butterfly needle insertion site, 6 cases of hospital readmission for equipment malfunction, and no cases of respiratory depression. Eleven patients continued standardized antitreatment after IDDS surgery. The mean survival time for all patients was 135.51 ± 102.69 days, and the survival rate at T7 was 30.61%. The cancer pain information platform combined with semi-implantable IDDS is beneficial for the pain management of refractory cancer patients under the “home analgesia” model, improving their quality of life.
Electrocatalytic Ammonia Synthesis Process on the Mo2TiC2 MXene.
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•Nineteen different possible pathways (five association pathway and fourteen dissociation pathway) analyzed by DFT ...calculation and Gibbs free energy calculation.•Valid N2-philicity, N≡N triple bond of the N2 molecule (the optimal distance) is sufficiently activated, from 1.11 Å to 1.268Å•Mo2TiC2 MXene can reduce the overpotential by changing the reaction pathway.•Mo2TiC2 as an ordered, double transition metals carbides is an eligible electrocatalyst for the NRR
Electrocatalytic ammonia synthesis provides an energy-efficient alternative to the Haber−Bosch process. The aim is to find promising electrocatalysts which are able to change the reaction pathway and reduce the overpotential. Here, based on density functional theory, a comprehensive mechanism study of the N2 activation and NH3 synthesis on the Mo2TiC2 MXenes is presented. For catalytic reaction mechanism, nineteen different possible pathways are screened for the lowest overpotential, where the corresponding potential-determining step are compared by Gibbs free energy calculation. The result reveals Mo2TiC2 MXenes exhibit both valid N2-philicity and high catalytic activity for electrocatalytic ammonia synthesis through a dissociation mechanism with a low overpotential of 0.26 V. Further, the competing reaction of H2 evolution is simultaneously suppressed which shows a relatively high potentials of 0.74 V. This study shows a brand new material for catalyzing NH3 synthesis under ambient conditions and provides the theory background to reduce the overpotential by changing the reaction pathway.
Arbitrary image stylization by neural networks has become a popular topic, and video stylization is attracting more attention as an extension of image stylization. However, when image stylization ...methods are applied to videos, unsatisfactory results that suffer from severe flickering effects appear. In this article, we conducted a detailed and comprehensive analysis of the cause of such flickering effects. Systematic comparisons among typical neural style transfer approaches show that the feature migration modules for state-of-the-art (SOTA) learning systems are ill-conditioned and could lead to a channelwise misalignment between the input content representations and the generated frames. Unlike traditional methods that relieve the misalignment via additional optical flow constraints or regularization modules, we focus on keeping the temporal consistency by aligning each output frame with the input frame. To this end, we propose a simple yet efficient multichannel correlation network (MCCNet), to ensure that output frames are directly aligned with inputs in the hidden feature space while maintaining the desired style patterns. An inner channel similarity loss is adopted to eliminate side effects caused by the absence of nonlinear operations such as softmax for strict alignment. Furthermore, to improve the performance of MCCNet under complex light conditions, we introduce an illumination loss during training. Qualitative and quantitative evaluations demonstrate that MCCNet performs well in arbitrary video and image style transfer tasks. Code is available at https://github.com/kongxiuxiu/MCCNetV2 .
A series of transition metals have strong interaction with MXene, the more charge transferred, the stronger energy is.
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•Strong-interaction mechanisms of transition metals-MXene were ...identified both electronically and geometrically.•Both adsorption energy and substitution energy are linearly with bond distances.•The adsorption energies and bader charge were proved to be linearly related.•Volcano-curve law markedly appears between substitution energies and bader charges.
Chemical modification of MXenes, as an effective strategy to improve the electronic harmony with other materials, paves huge impetus to their practically industrial application. In this study, by means of Density Functional Theory (DFT) calculations, the adsorption and substitution of single transition metal atoms (M = 3d (Fe, Co, Ni, Cu, Zn), 4d (Ru, Rh, Pd, Ag, Cd), 5d (Os, Ir, Pt, Au, Hg)) on Ti3C2 MXene have been systematically investigated. It is found that the adsorption (adsorption energies Ead = −1.05 ∼ −7.98 eV) of single metal atoms on Ti3C2 are much stronger than those on graphene and graphyne. Interestingly, via a series of electronical structure calculations, we found good linear correlation between Ead and chemically properties (such as the average bond distances dM-Ti, the bader charge and the d-electron centre of metal), shedding light on the harmonic effect of doping metals both electronical and geometrically. In other words, the stronger adsorption, shorter bond distance, more bader charge, less negative d-electron centre. While for the substitution of single metal atom on Ti3C2, a linear relationship is also found except that the volcano curve are formed between the substitution energies and bader charges. Moreover, the charge transfer decrease firstly and then increase in both first and third layer. Generally, single-atom adsorption or substitution is a feasible method to improve the functionalization Ti3C2 MXene.
Electrocatalytic ammonia synthesis under mild conditions is an attractive and challenging process in the earth's nitrogen cycle, which requires efficient and stable catalysts to reduce the ...overpotential. The N2 activation and reduction overpotential of different Ti3C2O2-supported transition metal (TM) (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ru, Rh, Pd, Ag, Cd, and Au) single-atom catalysts have been analyzed in terms of the Gibbs free energies calculated using the density functional theory (DFT). The end-on N2 adsorption was more energetically favorable, and the negative free energies represented good N2 activation performance, especially in the presence Fe/Ti3C2O2 (−0.75 eV). The overpotentials of Fe/Ti3C2O2, Co/Ti3C2O2, Ru/Ti3C2O2, and Rh/Ti3C2O2 were 0.92, 0.89, 1.16, and 0.84 eV, respectively. The potential required for ammonia synthesis was different for different TMs and ranged from 0.68 to 2.33 eV. Two possible potential-limiting steps may be involved in the process: (i) hydrogenation of N2 to *NNH and (ii) hydrogenation of *NH2 to ammonia. These catalysts can change the reaction pathway and avoid the traditional N–N bond-breaking barrier. It also simplifies the understanding of the relationship between the Gibbs free energy and overpotential, which is a significant factor in the rational designing and large-scale screening of catalysts for the electrocatalytic ammonia synthesis.
The overpotential of electrolytic ammonia synthesis is determined by the Gibbs free energies of two potential-limiting steps N2 + H+ → NNH (ΔG1) and NH2 + H+ → NH3 (ΔG2).
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