- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Ligand-Triggered Tunable Charge Transfer toward Multifarious Photoreduction Catalysis
摘要： Metal/semiconductor heterostructures have been arousing persistent interest on account of prominent roles of metal nanocrystals (NCs) in modulating charge transfer in photocatalysis. It has been generally accepted that ligands capped on the tailor-made metal NCs surface should be removed for exposing more active sites and the interface between metal and semiconductor should be clean enough to facilitate charge flow. Whether the ligands of metal NCs would definitely deteriorate charge separation/transfer and what is its correlation with photoactivity? Inspired by this motivation, herein, interface configuration between metal and semiconductor were exquisitely designed by a ligand-triggered electrostatic self-assembly strategy, wherein tailor-made intrinsically positively charged Pd NCs capped with hierarchically branched ligands (DMAP) and negatively charged surface-modified CdS nanowires (NWs) were judiciously utilized as the building blocks. Significantly, spontaneous and monodispersed immobilization of Pd@DMAP on the CdS NWs was readily initiated by DMAP ligands, which endows self-assembled Pd@DMAP/CdS NWs heterostructure with conspicuously enhanced and versatile photoreduction performances in comparison with CdS NWs toward anaerobic photoreduction of aromatic nitro compounds, photocatalytic hydrogen generation and photoreduction of heavy metal ions under visible light irradiation, owing to the crucial role of Pd@DMAP for efficaciously capturing electrons without the inhibition of hierarchical ligand structure and interfacial integration mode. More intriguingly, interfacial distance between Pd@DMAP and CdS NWs was finely mediated to achieve tunable charge transport. Finally, ligand-involved photocatalytic mechanism was elucidated. It is anticipated that our work could shed new insight on the role of ligand in modulating the directional charge transfer over metal/semiconductor photocatalytic system for substantial solar energy conversion.
更新于2025-11-19 16:51:07
-
Cascade charge transfer mediated by <i>in situ</i> interface modulation toward solar hydrogen production
摘要： Exquisite modulation of spatial charge transfer has been deemed an e?cacious strategy to boost the solar conversion e?ciency. Nevertheless, tunable control over directional charge transfer in photocatalysis to ideal reaction sites still constitutes a challenging task. In this work, cadmium sul?de (CdS), one of the most quintessential transition metal sul?des, was used to demonstrate how to progressively construct a cascade charge transfer channel via in situ phase self-transformation coupled with favorable interface engineering. The in situ phase self-transformation of CdS to CdSe on the surface was triggered followed by electrostatic self-assembly of MoS2 quantum dots (QDs) on the CdS@CdSe core–shell nanostructure, resulting in a CdS@CdSe-MoS2 QD ternary heterostructure with well-de?ned tailor-made interfaces. Signi?cantly, CdS@CdSe-MoS2 QDs demonstrated conspicuously enhanced photocatalytic water splitting performance in comparison with their single and binary counterparts under visible light irradiation along with favorable photostability and substantial apparent quantum yield. This is predominantly ascribed to the generation of a cascade charge transport channel in the ternary heterostructure arising from the cooperativity of in situ CdSe encapsulation and pinpoint MoS2 QD decoration. More importantly, the in situ formed ultrathin CdSe interlayer plays a crucial role in mediating the charge transfer cascade, a?ording suitable energy level alignment, and shielding the defect sites of CdS NWs, thereby markedly retarding charge recombination and prolonging the lifetime of charge carriers. Furthermore, self-assembled MoS2 QDs on the CdS@CdSe core–shell framework further contribute to the directional charge ?ow to the active sites for hydrogen production.
更新于2025-11-19 16:51:07
-
Highly efficient solar steam generation via mass-produced carbon nanosheet frameworks
摘要： Carbon nanosheet frameworks are synthesized on the gram scale by exploiting the reaction between Mg powder and CS2 vapor. This fluffy carbon nanomaterial coated on fabric shows high performance in solar steam generation. The carbon film has high optical absorption of ~98% in visible and infrared spectrum. When under 1 sun solar-simulated light irradiance (1000 W m-2), the surface temperatures of dry and water-saturated carbon films reach 104 and 45 oC, respectively, indicating good heat localization. As a result, the carbon film under 1 sun illumination shows a high solar-to-vapor efficiency of 93%, which is higher than that of most photothermal conversion materials reported previously. The as-prepared carbon material may pave the way for harvesting solar energy to produce clean water at low cost.
关键词： solar steam generation,Mg thermoreduction,photothermal conversion,carbon nanosheet,vapor-solid reaction
更新于2025-09-23 15:23:52
-
3D graphene aerogels/Sb2WO6 hybrid with enhanced photocatalytic activity under UV- and visible-light irradiation
摘要： A novel ultraviolet (UV)- and visible-light-active 3D graphene aerogels (3DGA)/Sb2WO6 hybrid photocatalyst was prepared by electrostatic self-assembly (ESSA) method. The photocatalytic activity of the 3DGA/Sb2WO6 hybrid was studied by monitoring the change in the concentration of methyl orange (MO) under UV-light and visible-light irradiation. The results demonstrated that the as-prepared hybrid exhibited significantly enhanced efficiency for the photodegradation of MO in comparison with pure Sb2WO6. This was ascribed to the efficient separation of the photogenerated electrons (e–) and holes (h+) with the aid of 3DGA as well as the generated reactive superoxide radical anions (O2(cid:129)–). Moreover, the 3DGA/Sb2WO6 hybrid exhibited high recyclability, because the highly hydrophobic 3DGA in the hybrid was very advantageous to the separation of the hybrid photocatalyst from the MO solutions.
关键词： 3D graphene aerogels,Sb2WO6,Electrostatic self-assembly,Hybrid photocatalyst,Visible-light irradiation
更新于2025-09-23 15:21:21
-
Effects of material degradation on electrical and optical characteristics of surface dielectric barrier discharge
摘要： In this paper, screen-printed electrodes are asymmetrically fabricated on three different dielectrics (multi-layered polyimide, quartz, and alumina). Supplied with AC power, sustainable surface dielectric barrier discharge (SDBD) plasma is generated in atmospheric pressure. During plasma processing, different changes of material degradation and discharge images are observed. The corresponding electrical and optical characteristics are investigated by optical emission spectra (OES) and Lissajous figure analysis, respectively. It is found that both dielectric degradation and electrode erosion occur on the surface of the polyimide based SDBD device, while there is only electrode erosion for the quartz and alumina based devices, which results in different changes of electrical characteristics. OES calculated results show that with an increase of discharge aging time, electron temperature increases for the polyimide based SDBD device and decreases for quartz and alumina based SDBD devices, while all the gas temperatures of three dielectrics increase with the aging time. Furthermore, compared to vibrational temperature and gas temperature, the distribution of electron temperature is more suitable for evaluating the changes in discharge uniformity during plasma processing.
关键词： electrical characteristics,plasma processing,optical characteristics,surface dielectric barrier discharge,material degradation
更新于2025-09-23 15:21:21
-
Remote Phononic Effects in Epitaxial Ruddlesden-Popper Halide Perovskites
摘要： Despite their weak nature, van der Waals (vdW) interactions have been shown to effectively control the optoelectronic and vibrational properties of layered materials. However, how vdW effects exist in Ruddlesden-Popper layered halide perovskites remains unclear. Here we reveal the role of interlayer vdW force in Ruddlesden-Popper perovskite in regulating phase transition kinetics and carrier dynamics, based on high-quality epitaxial single crystalline (C4H9NH3)2PbI4 flakes with controlled dimensions. Both substrate-perovskite epitaxial interaction and interlayer vdW interaction play significant roles in suppressing the structural phase transition. With reducing flake thickness from ~100 nm to ~20 nm, electron-phonon coupling strength decreases by ~30%, suggesting the ineffectiveness of phonon confinement of the natural quantum wells. Therefore, the conventional understanding that vdW perovskite is equivalent to a multiple quantum well has to be substantially amended due to significant nonlocal phononic effects in the layered crystal where intralayer interaction is not drastically different from the interlayer force.
关键词： phase transition,electron-phonon coupling,Ruddlesden-Popper perovskites,epitaxial growth,van der Waals interactions
更新于2025-09-23 15:21:01
-
Probing the Advantageous Photosensitization Effect of Metal Nanoclusters over Plasmonic Metal Nanocrystals in Photoelectrochemical Water Splitting
摘要： Atomically precise metal nanoclusters (NCs)-based photocatalytic systems have garnered enormous attention owing to the fascinating merits including unique physicochemical properties, quantum confinement effect and photosensitization effect, which are distinct from conventional metal nanocrystals (NYs). Nevertheless, systematic comparison between electrons photoexcited from metal NCs and hot electrons from surface plasmonic resonance (SPR) effect of metal NYs in boosting photoelectrochemical water splitting reaction remains blank. Here, we report the strict and comprehensive comparison on the capability of electrons photoexcited from glutathione-capped gold nanoclusters (Aux@GSH) and hot electrons from plasmonic excitation of gold nanoparticles (Au NYs) self-transformed from Aux@GSH to trigger the PEC water splitting reaction under visible light irradiation. The results indicate photoelectrons of Aux NCs trigger more efficient charge transport rate than hot electrons of plasmonic Au NYs in terms of light harvesting and conversion efficiency under the identical conditions. Moreover, charge transfer characteristics in Aux NCs and Au NYs-based PEC systems were established. This work would reinforce our deep understanding on these two pivotal sectors of metal nanomaterials for solar energy conversion.
关键词： photosensitization effect,plasmonic metal nanocrystals,charge transfer,photoelectrochemical water splitting,metal nanoclusters
更新于2025-09-23 15:19:57
-
Controlled deposition of size-selected metal nanoclusters on prepatterned substrate
摘要： An endeavor of organizing Cu nano-particles of controlled size in ordered arrays at room temperature is reported. This involves the guided deposition of size-selected nanoparticles otherwise known as nanoclusters via periodic modulation of the substrate surface. Ultra-high vacuum compatible magnetron-based gas-aggregation type source combined with a quadrupole mass filter has been employed to produce the size-selected nanoclusters whereas the surface modulations (ripples) in the nanoscale are induced by low energy oblique angle ion beam irradiation. Morphological aspects of deposited nanoclusters and the substrates were characterized by high-resolution scanning electron microscopy (HRSEM) and atomic force microscopy (AFM). The chemical composition of the deposited nanoclusters was characterized by x-ray photoelectron spectroscopy. The alignment of size-selected metal nanoclusters along the substrate-patterns is observed. Depending upon deposition conditions quality of the organization varies. The optimum angle of deposition for the improved alignment depends on the pattern parameters of the substrate.
关键词： Ion sputtering,Room-temperature organization,Metal nanocluster,Patterned substrate,Supported clusters,Scanning Electron Microscopy
更新于2025-09-23 15:19:57
-
Variable densification of reduced graphene oxide foam into multifunctional high-performance graphene paper
摘要： Super-flexible, electrically and thermally conductive graphene-based papers are in great demand in the fields of electronics and supercapacitors. However, the applications of graphene-based papers are limited either by their brittleness, small scale, or by their unsatisfactory thermal conductivity. Conventionally, such papers are fabricated by vacuum-assisted filtration, direct evaporation, electrospray coating, or wet spinning. Here we propose a novel strategy, namely, direct densification of reduced graphene oxide foam, to fabricate large-scale multifunctional graphene papers. The graphene paper density could be adjusted by applying different loads. The densities of the graphene papers varied from 0.32 g cm?3 to 1.85 g cm?3. The thermal conductivity, tensile stress, electrical conductivity and electromagnetic interface shielding effectiveness increased with an increase in the density of the graphene paper. When the density of the graphene paper reached 1.85 g cm?3, the tensile stress was up to 50.4 MPa with strain of 4%, the thermal conductivity was 1103 W m?1 K?1 at room temperature and there was high electrical conductivity of 1.1 × 10? S m?1, as well as an electromagnetic interference (EMI) shielding effectiveness of 77.2 dB. Our new strategy is very promising in terms of controlling the thickness, density, and size of graphene paper.
关键词： graphene paper,densification,EMI shielding,electrical conductivity,thermal conductivity
更新于2025-09-19 17:15:36
-
Regulating Spatial Charge Transfer Over Intrinsically Ultrathin-Carbon-Encapsulated Photoanode Toward Solar Water Splitting
摘要： Photoinduced charge separation and transfer have been deemed as the core factor affecting the efficiency of photoelectrocatalysis; precisely modulating the spatial migration of photo-induced charge carriers to the ideal reaction sites is of paramount importance for boosting the solar conversion efficiency of photoelectrochemical (PEC) cell. In this work, a combinatorial strategy has been developed to progressively construct highly efficient charge transport channels on the quintessential electrochemically anodized one-dimensional semiconductor framework (TiO2 nanotube arrays, TNTAs) by an in-situ annealing-induced intrinsic ultrathin carbon encapsulation. Antimony sulfide (Sb2S3) nanocrystals were subsequently attached on the interior and exterior surfaces of carbon-encapsulated TNTAs (C-TNTAs) substrate forming well-defined ternary photoanode (C-Sb2S3-TNTAs) capable of triggering smooth and cascade electron transfer. Cooperativity stemming from the intrinsic carbon encapsulation on the surface for fast electron transport in conjunction with Sb2S3 photosensitization for substantial visible light harvesting endow C-Sb2S3-TNTAs heterostructure with markedly enhanced solar-powered PEC water dissociation performances, conspicuously exceeding single and binary counterparts. Furthermore, hole transport pathway was further constructed by site-selective incorporation of oxygen evolving catalyst (Co-Pi) in the ternary system via photo-assisted electrodeposition or electrodeposition approach, which contributes to more enhanced separation efficiency and prolonged lifetime of photo-induced charge carriers together with improved photostability. It is expected that our work would afford a new frontier to intelligently mediate the spatial directional flow of photogenerated charge carriers and rationally construct efficient charge transport channels on the semiconductor-based photoelectrodes for high-efficiency solar energy harvesting and conversion.
更新于2025-09-19 17:15:36