Solar‐driven syngas production by CO2 reduction provides a sustainable strategy to produce renewable feedstocks. However, this promising reaction often suffers from tough CO2 activation, sluggish ...oxidative half‐reaction kinetics and undesired by‐products. Herein, we report a function‐oriented strategy of deliberately constructing black phosphorus quantum dots‐ZnIn2S4 (BP/ZIS) heterostructures for solar‐driven CO2 reduction to syngas, paired with selectively oxidative C−N bond formation, in one redox cycle. The optimal BP/ZIS heterostructure features the enhanced charge‐carrier separation and enriched active sites for cooperatively photocatalytic syngas production with a tunable ratio of CO/H2 and efficient oxidation of amines to imines with high conversion and selectivity. This prominent catalytic performance arises from the efficient electronic coupling between black phosphorus quantum dots and ZnIn2S4, as well as the optimized adsorption strength for key reaction intermediates, as supported by both experimental and theoretical investigations. We also demonstrate a synergistic interplay between CO2 reduction and amine dehydrogenation oxidation, rather than simply collecting these two single half‐reactions in this dual‐functional photoredox system.
A function‐oriented strategy of engineering black phosphorus quantum dots‐ZnIn2S4 heterostructures for solar‐driven CO2 reduction to syngas, paired with selectively oxidative C−N bond formation, in one redox cycle is reported. The promoted charge‐carrier separation, enriched active sites and optimized adsorption strength of key reaction intermediates for CO2 reduction, as well as the cooperative photoredox manner, jointly contribute to the enhanced photoactivity and selectivity.
Two new water-stable cadmium(ii)-metal organic frameworks (MOFs), namely Cd2(L1)(1,4-NDC)2n (1) and Cd(L2)(1,4-NDC)n (2) (L1 = 1,4-bis(benzimidazol-1-yl)-2-butylene, L2 = ...1,4-bis(2-methylbenzimidazol-1-yl)-2-butylene and 1,4-H2NDC = 1,4-naphthalenedicarboxylic acid), were synthesized and characterized. 1 exhibits an unusual 3D framework with the Schläfli symbol of {42·5·62·7}{42·52·72}{42·53·62·73}2, and 2 is a classical sqc6 network. 1 and 2 display excellent pH and water stability, and the integrity of the frameworks was well maintained at different pH values (pH = 3–13) and after long-term water treatment. 1 is the first dual-function luminescent sensor for sensing acetylacetone and Cr2O72− in aqueous solutions with high sensitivity, selectivity and excellent recyclability. This material is an excellent dual-responsive recyclable luminescent sensor.
Enormous research interest is devoted to fabricating three-dimensional graphene-based gels (3D GBGs) toward improved conversion of solar energy by virtue of the intrinsic properties of single ...graphene and 3D porous structure characteristics. Here, this concise minireview is primarily focused on the recent progress on applications of 3D GBGs, including aerogels and hydrogels, in photocatalytic degradation of pollutants from water and air, such as organic pollutants, heavy metal ions, bacteria and gaseous pollutants. In particular, the preponderances of 3D GBG photocatalysts for environmental pollutants degradation have been elaborated. Furthermore, in addition to discussing opportunities offered by 3D GBG composite photocatalysts, we also describe the existing problems and the future direction of 3D GBG materials in this burgeoning research area. It is hoped that this review could spur multidisciplinary research interest for advancing the rational utilization of 3D GBGs for practical applications in environmental remediation.
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•3D graphene-based gels (3D GBGs) possess more active sites.•Porous structure of 3D GBGs promotes the photogenerated electrons transfer.•3D framework provides an ideal support for the active components.•Applications of 3D GBGs in photocatalytic environmental remediation are overviewed.
Neuroinflammation has been demonstrated to be linked with Parkinson's disease (PD), Alzheimer's disease, and cerebral ischemia. Our previous investigation had identified that kaempferol (KAE) exerted ...protective effects on cortex neuron injured by LPS. In this study, the effects and possible mechanism of KAE on striatal dopaminergic neurons induced by LPS in mice were further investigated. The results showed that KAE improved striatal neuron injury, and increased the levels of tyrosine hydroxylase (TH) and postsynaptic density protein 95 (PSD95) in the striatum of mice. In addition, KAE inhibited the production of pro-inflammatory cytokines, including interleukin 1β (IL-1β), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), reduced the level of monocyte chemotactic protein-1 (MCP-1), intercellular cell adhesion molecule-1 (ICAM-1), and cyclooxygenase-2 (COX-2) in the striatum tissues. Furthermore, KAE protected blood-brain barrier (BBB) integrity and suppressed the activation of the HMGB1/TLR4 inflammatory pathway induced by LPS in striatum tissues of mice. In conclusion, these results suggest that KAE may have neuroprotective effects against striatum injury that is induced by LPS and the possible mechanisms are involved in anti-neuroinflammation, maintaining BBB integrity, and down-regulating the HMGB1/TLR4 pathway.
The development of efficient catalyst for photoredox-catalyzed selective organic synthesis has consitently been an attractive objective in recent years. Regarding semiconductor-based photocatalysts, ...cadmium sulfide (CdS) materials have received extensive consideration for various photoredox reactions because of their suitable band gap (about 2.4 eV) for visible light response and well-matched band edge stations. In this paper, we begin with a concise discussion of the basic physical properties of CdS materials, including electronic band structures, optical properties, crystallographic structures, and phase transition. Then, the fundamental principles of photocatalytic organic transformations over CdS and the effect of different active species on the selective photoredox process are concisely summarized. In particular, we will highlight the photocatalytic selective organic synthesis application over various CdS-based photocatalysts, including selective reductions, oxidations, and valorization of lignin. Finally, the future perspectives and challenges in the development of efficient CdS-based photocatalytic system toward selective organic synthesis are discussed. It is anticipated that this timely overview of recent advances in selective organic synthesis over CdS-based materials would inspire the rational design of CdS or other semiconductor-based catalysts with ameliorated performances toward a variety of artificial photoredox-catalyzed selective organic transformations to value-added feedstocks and beyond.
Highly-efficient oxygen evolution reaction (OER) and reduction of carbon dioxide (CO 2 RR) represent the two biggest scientific challenges in artificial photosynthesis. Many efficient and ...cost-affordable electrocatalysts have been reported in the development of electrochemical OER and CO 2 RR; however, during the electro-derived oxidation or reduction processes, a critical fact that, most catalysts tend to undergo structural reconstruction and/or surface rearrangement, has been widely observed, which greatly subverts the traditional conception of “catalysts”. In this respect, the research trends have gradually transferred from optimizing catalyst materials to elucidating the real active sites of the catalysts as well as understanding the underlying mechanisms behind these complex reactions. Most importantly, the in situ / operando characterization techniques are powerful tools to achieve this goal. Herein, recent advances in the in situ X-ray diffraction and absorption spectroscopy that have provided a unique opportunity to investigate the structural reconstruction and/or surface rearrangement of catalysts under realistic OER and CO 2 RR conditions are thoroughly reviewed. Finally, the challenges of the material design are discussed, and the future perspective for developing next-generation catalysts with imperative requirements of material nature is provided.
Abstract
The performance of transition metal hydroxides, as cocatalysts for CO
2
photoreduction, is significantly limited by their inherent weaknesses of poor conductivity and stacked structure. ...Herein, we report the rational assembly of a series of transition metal hydroxides on graphene to act as a cocatalyst ensemble for efficient CO
2
photoreduction. In particular, with the Ru-dye as visible light photosensitizer, hierarchical Ni(OH)
2
nanosheet arrays-graphene (Ni(OH)
2
-GR) composites exhibit superior photoactivity and selectivity, which remarkably surpass other counterparts and most of analogous hybrid photocatalyst system. The origin of such superior performance of Ni(OH)
2
-GR is attributed to its appropriate synergy on the enhanced adsorption of CO
2
, increased active sites for CO
2
reduction and improved charge carriers separation/transfer. This work is anticipated to spur rationally designing efficient earth-abundant transition metal hydroxides-based cocatalysts on graphene and other two-dimension platforms for artificial reduction of CO
2
to solar chemicals and fuels.
Two new coordination polymers (CPs), Cd(L)(NTA)n (1) and Ni(L)(NPTA)·H2On (2) (L = 1,6-bis(benzimidazol-1-yl)hexane, H2NTA = 2-nitroterephthalic acid and H2NPTA = 3-nitrophthalic acid) were ...prepared under solvothermal conditions. Both CPs exhibit 2D layered structures with sql and hcb network, respectively. 1 and 2 are further extend into 3D supramolecular networks by π–π stacking interactions. The luminescent experiments show that 1 and 2 can serve as efficient probes for sensing acetylacetone (acac) with high quenching efficiency (Ksv = 1258 M–1 for 1, 4841 M–1 for 2) and low detection limit (3.63 μM for 1 and 0.79 μM for 2). 1 and 2 also possess selective and sensitive sensing for Hg2+ with quenching efficiency 3565 M–1 for 1 and 7432 M–1 for 2 and low detection limit 3.05 μM for 1, 2.29 μM for 2, respectively. When acac and Hg2+ ions are at a low concentration, there are good linear relationships between concentrations and quenching efficiencies. 1 and 2 represent the first example based on CPs as luminescent chemosensors for acac and Hg2+ ions detection.
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•Two new coordination polymers based on flexible bis(benzimidazole) ligand were synthesized and characterized.•1 and 2 exhibited highly sensitive and selective sensing for acac and Hg2+.•The luminescence quenching mechanism of Hg2+ were discussed.
Tribulus terrestris L. (Zygophyllaceae) (TT) is usually used as a cardiotonic, diuretic, and aphrodisiac, as well as for herbal post-stroke rehabilitation in traditional Chinese medicine. However, ...little is known about the renoprotective effects of TT on obesity-related glomerulopathy (ORG). In this study, 340 monomeric compounds were identified from TT extracts obtained with ethyl acetate combined with 50% methanol. In vitro, IC50 of TT was 912.01 mg/L, and the appropriate concentration of TT against oxidized-low density lipoprotein (ox-LDL) induced human renal glomerular endothelial cells (HRGECs) was 4 mg/L. TT significantly increased the viability (63.2%) and migration (2.33-fold increase) of HRGECs. ORG model rats were induced by a chronic high-fat diet (45%) for 20 weeks and were then treated with TT extract (2.8 g/kg/d) for 8 weeks. Subsequently, the kidneys were removed and their differentially expressed protein profile was identified using two-dimensional electrophoresis coupled with matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF)-TOF MS. Molecular categorization and functional analysis of bioinformatic annotation suggested that excessive energy metabolism, decreased response to stress and low immunity were the potential etiologies of ORG. After TT administration for 8 weeks, body weight, blood pressure, serum cystatin C and cholesterol were decreased. Additionally, TT significantly enhanced the resistance of rats to ORG, decreased energy consumption and the hemorrhagic tendency, and improved the response to acute phase reactants and immunity. In conclusion, TT may play a protective role against ORG in rats.
In this study, a novel scheme is proposed for bidirectional beamforming using time‐modulated linear arrays (TMLAs). A beamforming method with a time shift was adopted to obtain the bidirectional ...pattern with the +1st harmonic using two switching sequences. Furthermore, the genetic algorithm was modified to obtain an additional beam using the fundamental component. In the proposed approach, the direction and sidelobe of the beam can be controlled by designing switching sequences, resulting in low complexity and a flexible structure in case of bidirectional beamforming. The simulation results show the effectiveness of the proposed methods, and the levels of the sidelobe and null were reduced to −20 and −53.7 dB, respectively.
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