In recent years, strenuous efforts have been devoted to exploring ZnO functionalized TiO2 nanotube arrays (ZnO/TNTs) nanocomposites; however, there is still a paucity of reports on the construction ...of well-defined ZnO/TNTs heterostructure via efficient and easily accessible approach. In this work, drawing on a two-step anodization combined pyrolysis strategy, we attained a highly ordered ZnO/TNTs hybrid nanostructure. Combined with a collection of characterizations including X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), diffusion reflectance spectrum (DRS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), we found that, in this coupling, in situ formed ZnO phases were uniformly grafted to TNTs framework giving rise to hybrid nanostructure, which is ascribed to cooperative interfacial interaction between polar TiO2 layer and ZnO precursor. The underlying interaction leading to judicious combination of TNTs and ZnO was unveiled by Fourier transformed infrared spectrum (FTIR) and XPS. Alternatively, it has been shown that ZnO nanocrystals distributed on the TNTs could serve as favorable hole channels and receptors for efficient separation of photoexcited charge carriers, which results in significantly enhanced photocatalytic performances of ZnO/TNTs heterostructure in comparison with pure TNTs, ZnO film, and P25 particulate film. Furthermore, it is found that the hybrid photocatalyst demonstrated excellent photostability. It is hoped that our work could present a straightforward paradigm for preparation of hierarchical semiconductor/1-D semiconductor heterostructures.
Although recent years have witnessed considerable progress in the synthesis of metal clusters, there is still a paucity of reports on photoelectrochemical (PEC) properties of metal ...cluster/semiconductor systems for solar energy conversion. In this work, highly ordered glutathione (GSH)-protected gold (Au) cluster (Au
@GSH) enwrapped ZnO nanowire array (NW) heterostructures (Au
/ZnO NWs) were designed by a facile, green, simple yet efficient in situ etching-induced electrostatic self-assembly strategy by modulating the intrinsic surface charge properties of building blocks, which renders negatively charged Au
clusters spontaneously and uniformly self-assembles them on positively charged ZnO NWs framework with intimate interfacial integration. It was unraveled that such Au
/ZnO NWs heterostructures demonstrated significantly enhanced PEC water splitting performance in comparison with single ZnO NWs, Au nanoparticles (Au/ZnO NWs) and GSH-capped Ag
clusters (Ag
/ZnO NWs) decorated ZnO NWs counterparts under both simulated solar and visible light irradiation. The vitally important role of Au
clusters as photosensitizer was unambiguously revealed and the merits of Au
clusters in boosting charge transfer arising from their unique core-shell architecture were highlighted by systematic comparison under identical conditions, based on which Au
cluster-mediated PEC water splitting mechanism is delineated. It is anticipated that our work can highlight the possibility of harnessing metal clusters as efficient light-harvest antennas and open new avenues for rational construction of various highly energy efficient metal cluster/semiconductor heterostructures for widespread photocatalytic and PEC applications.
Recent years have witnessed increasing interest in the solution‐phase synthesis of atomically precise thiolate‐protected gold clusters (Aux); nonetheless, research on the photocatalytic properties of ...Aux–semiconductor nanocomposites is still in its infancy. In this work, recently developed glutathione‐capped gold clusters and highly ordered nanoporous layer‐covered TiO2 nanotube arrays (NP‐TNTAs) are employed as nanobuilding blocks for the construction of a well‐defined Aux/NP‐TNTA heterostructure via a facile electrostatic self‐assembly strategy. Versatile photocatalytic performances of the Aux/NP‐TNTA heterostructure which acts as a model catalyst, including photocatalytic oxidation of organic pollutant, photocatalytic reduction of aromatic nitro compounds and photoelectrochemical (PEC) water splitting under simulated solar light irradiation, are systematically exploited. It is found that synergistic interaction stemming from monodisperse coverage of Aux clusters on NP‐TNTAs in combination with hierarchical nanostructure of NP‐TNTAs reinforce light absorption of Aux/NP‐TNTA heterostructure especially within visible region, hence contributing to the significantly enhanced photocatalytic and PEC water splitting performances. Moreover, photocatalytic and PEC mechanisms over Aux/NP‐TNTA heterostructure are elucidated and corresponding reaction models were presented. It is anticipated that this work could boost new insight for photocatalytic properties of metal‐cluster‐sensitized semiconductor nanocomposites.
A well‐defined heterostructure consisting of monodisperse Au clusters and hierarchically ordered nanoporous TiO2 nanotube arrays (Aux/NP‐TNTAs) is fabricated via a facile two‐step anodization approach combined with efficient electrostatic self‐assembly. The hierarchically ordered Aux/NP‐TNTA heterostructure demonstrates versatile photocatalytic redox and photoelectrochemical performances under simulated solar light irradiation under ambient conditions.
Atomically precise metal nanoclusters (NCs) have garnered tremendous attention as light‐harvesting antennas in heterogeneous photocatalysis due to unique atomic stacking mode, quantum confinement ...effect, and enriched active sites. However, metal NCs as photosensitizers suffer from extremely short carrier lifetime, poor photostability, and difficulty in carrier migration, which hinder the wide‐spread utilization of metal NCs in solar energy conversion. To solve these problems, herein, Ag‐doped glutathione (GSH)‐capped gold NCs, i.e., alloy Au1−xAgx@GSH NCs and non‐conjugated insulating polymer of poly(diallyl‐dimethylammonium chloride) (PDDA) are utilized as the building blocks for layer‐by‐layer assembly of spatially multilayered alloy NCs/metal oxide (MO) photosystems. The alternately deposited ultrathin PDDA layer in‐between Au1−xAgx@GSH NCs on the MO substrate functions as an efficient charge flow mediator to relay the directional photoelectron transfer over Au1−xAgx@GSH NCs, giving rise to the cascade charge transfer chain. This peculiar carrier migration mode endowed by exquisite interface configuration design significantly boosts the unidirectional electron migration from the Au1−xAgx@GSH NCs to the MO substrate, substantially improving the visible‐light‐driven photoelectrochemical water oxidation performances of MO/(PDDA‐Au1−xAgx)n multilayer heterostructured photoanodes. The work will inspire the rational construction of alloy metal NCs‐based photosystems for modulating spatially controllable charge transfer pathway for solar energy conversion.
Cascade charge transfer channel is elaborately designed over alloy nanoclusters via a facile, easily accessible, and efficient layer‐by‐layer assembly strategy for boosted photoelectrochemical water oxidation. The favorable energy level alignment between metal oxide and atomically precise alloy nanoclusters stimulates the advantageous interfacial charge migration and separation, prolonging the charge lifetime.
In recent years, increasing interest has been devoted to synthesizing graphene–semiconductor nanocomposites as efficient photocatalysts for extensive applications. Unfortunately, it is still ...challenging to make uniform graphene–semiconductor composite films with controllable film thickness and architecture, which are of paramount importance to meet the application requirements. In this work, stable aqueous dispersion of polymer-modified graphene nanosheets (GNs) was prepared via in situ reduction of exfoliated graphite oxide in the presence of cationic poly(allylamine hydrochloride) (PAH). The resultant water-soluble PAH-modified GNs (GNs-PAH) in conjunction with tailor-made negatively charged CdS quantum dots (QDs) were utilized as nanobuilding blocks for sequential layer-by-layer (LbL) self-assembly of well-defined GNs–CdS QDs hybrid films, in which CdS QDs overspread evenly on the two-dimensional (2D) GNs. It was found that the alternating GNs–CdS QDs multilayered films showed significantly enhanced photoelectrochemical and photocatalytic activities under visible light irradiation as compared to pure CdS QDs and GNs films. The enhancement was attributed to the judicious integration of CdS QDs with GNs in an alternating manner, which maximizes the 2D structural advantage of GNs in GNs–CdS QDs composite films. In addition, photocatalytic and photoelectrochemical mechanisms of the GNs–CdS QDs multilayered films were also discussed. It is anticipated that our work may open new directions for the fabrication of uniform semiconductor/GNs hybrid films for a wide range of applications.
Atomically precise metal nanoclusters (NCs) represent a promising generation of metal nanomaterial because of characteristic atomic stacking mode, abundant catalytic active sites, and molecular‐like ...discrete energy band structure. However, crafting metal NCs‐dominated photocatalytic systems with mediated charge transport pathways for photoredox catalysis is in the infant stage and their photocatalytic mechanisms remain elusive, which is largely hampered by the ultra‐short charge lifetime, generic instability, and complicated electronic structure of metal NCs. In this study, the smart construction of all‐solid‐state metal NCs‐transition metal chalcogenides quantum dots (TMCs QDs) Z‐scheme artificial photosystems for robust and stable solar‐to‐hydrogen conversion is demonstrated. The concurrent favorable photosensitization efficiency of metal NCs and TMCs QDs synergistically stimulate the unexpected Z‐scheme charge transport pathway, which significantly boosts the anisotropic spatial vectorial charge transport/separation, giving rise to considerably enhanced visible‐light‐responsive photocatalytic hydrogen generation performances along with favorable stability. This study would push forward the prosperity of exploring metal NCs‐based photosystems for solar‐to‐hydrogen conversion.
Atomically precise metal nanoclusters mediated Z‐scheme photosystems are for the first time exquisitely crafted for solar‐to‐hydrogen conversion. The favorable energy level alignment among Au25(GSH)18 nanoclusters, CdSe QDs, and MoSe2 along with elegant interface configuration modulation facilitates the directional charge migration and separation, giving rise to high‐performance Z‐scheme photosystem for photocatalytic hydrogen generation under visible light irradiation.
Surface plasmon resonance (SPR) effect of metal nanostructures is established as an efficient and attractive strategy to boost visible‐light or even near‐infrared‐responsive photo‐electrochemical ...(PEC) water splitting devices for substantial solar‐to‐chemical energy conversion. Rational integration of plasmonic metal nanostructures with semiconductors in an appropriate fashion is beneficial for creating a large variety of plasmonic metal/semiconductor photoelectrodes. However, up to date, construction of well‐defined and highly efficient plasmonic metal/semiconductor heterostructures is still in its infant stage. In this review, basic principles of PEC water splitting over semiconductors, SPR‐excited plasmonic effect of metal nanostructures, and their intrinsic correlation with each other are first concisely introduced. Subsequently, it is paid great attention to specifically summarize the diverse plasmonic metal/semiconductor photoelectrodes currently being extensively explored for indirect plasmon‐induced PEC water splitting. Particularly, different plasmonic metal/semiconductor nanoarchitectures including planar thin films, 1D composited, and 3D spatially hierarchical heterostructures are systematically classified and elucidated. Finally, future perspectives and challenges in triggering further innovative thinking on plasmon‐enhanced solar water splitting are envisaged. It is anticipated that this review can provide enriched information on rational design and construction of various plasmonic metal/semiconductor heterostructures for solar‐powered plasmon‐based PEC devices.
Surface plasmon resonance effect of metal nanostructures is established as an efficient and attractive strategy to boost visible‐light or even near‐infrared‐responsive photo‐electrochemical water splitting devices for substantial solar‐to‐chemical energy conversion. In this review article, different plasmonic metal/semiconductor nanoarchitectures including planar thin films, 1D composited, and 3D spatially hierarchical heterostructures are comprehensively and systematically elucidated.
With accelerating consumption of nonrenewable energy resource, mankind is currently facing the dilemma of energy crisis and global warming caused by excessive greenhouse gas emissions. ...Photoelectrocatalytic (PEC) technique to convert the main greenhouse gas CO2 into hydrocarbon fuels can solve these two issues with one stone. Herein, we summarize the latest developments of semiconductor-based PEC CO2 reduction for solar fuels production in a more comprehensive manner. Our endeavors start with elucidation of the fundamental principles of CO2 reduction technology and influencing factors of PEC CO2 reduction technique, followed by specific introduction on four quintessentially designed PEC CO2 reduction systems, and then multifarious photoelectrodes utilized for these photosystems are systematically introduced. Modification rationales for crafting photoelectrodes with high conversion efficiency and good stability are elucidated. Besides, strategies developed for fine-tuning of selectivity of PEC CO2 reduction products are also discussed. Finally, future outlooks and challenges in this booming research field are reviewed. It is anticipated that our Review would provide enriched and guided information on rational construction of high-performance photoelectrodes for solar-to-chemical fuels conversion.
CO2 reduction to carbon feedstocks using heterogeneous photocatalysis technique has been deemed as an attractive means of addressing both deteriorating greenhouse effect and depletion of fossil ...fuels. Nevertheless, deficiency of accessible active sites on the catalyst surface, low CO2 adsorption rate, and short carrier lifetime retard the photocatalytic CO2 conversion into hydrocarbon fuels. In this study, the controllable construction of spatially separated directional charge transport pathways over multilayered heterostructured transition metal chalcogenides (TMCs) based photosystems for high‐performance photocatalytic CO2‐to‐syngas conversion are shown. In this scenario, ultrathin non‐conjugated insulating poly(diallyl‐dimethyl‐ammonium chloride) (PDDA) layer are intercalated in‐between TMCs and layered double hydroxide (LDH) and serve as an efficient electron transfer mediator, whilst LDH functions as a hole‐withdrawing regulator, both of which synergistically foster the spatial vectorial charge migration/separation over TMCs, thus endowing the TMCs/PDDA/LDH heterostructures with significantly boosted visible‐light‐driven photoactivity toward CO2 conversion into syngas. This study can inspire sparkling new ideas to realize fine tuning of charge motion for stimulating solar‐to‐fuel conversion.
Ultrathin non‐conjugated insulating poly(diallyl‐dimethyl‐ammonium chloride) (PDDA) serves as an efficient electron transfer mediator, and simultaneously layered double hydroxide (LDH) functions as a hole‐withdrawing regulator, both of which synergistically contributes to the spatially separated bi‐directional charge transfer pathways over transition metal chalcogenides toward significantly boosted CO2 photoreduction catalysis under visible light irradiation.
Exosomes are a subpopulation of the tumour microenvironment (TME) that transmit various biological molecules to promote intercellular communication. Exosomes are derived from nearly all types of ...cells and exist in all body fluids. Noncoding RNAs (ncRNAs) are among the most abundant contents in exosomes, and some ncRNAs with biological functions are specifically packaged into exosomes. Recent studies have revealed that exosome-derived ncRNAs play crucial roles in the tumorigenesis, progression and drug resistance of gastric cancer (GC). In addition, regulating the expression levels of exosomal ncRNAs can promote or suppress GC progression. Moreover, the membrane structures of exosomes protect ncRNAs from degradation by enzymes and other chemical substances, significantly increasing the stability of exosomal ncRNAs. Specific hallmarks within exosomes that can be used for exosome identification, and specific contents can be used to determine their origin. Therefore, exosomal ncRNAs are suitable for use as diagnostic and prognostic biomarkers or therapeutic targets. Regulating the biogenesis of exosomes and the expression levels of exosomal ncRNAs may represent a new way to block or eradicate GC. In this review, we summarized the origins and characteristics of exosomes and analysed the association between exosomal ncRNAs and GC development.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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