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Additive‐Free Non‐Fullerene Organic Solar Cells
摘要： CeMnOx catalyst was synthesized by the combustion method, and the supported Ti/CeMnOx catalyst was subsequently prepared by wetness impregnation. Ti/CeMnOx catalyst exhibited higher N2 selectivity than CeMnOx catalyst in the selective catalytic reduction of NO by NH3 (NH3-SCR), and the generation of side products including in N2O and NO2 were discussed. N2 adsorption/desorption, X-ray di?raction (XRD), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (TPR), NH3 temperature-programmed desorption (TPD), and in situ di?use re?ectance infrared Fourier transform spectroscopy (DRIFTS) were carried out to reveal the promotion e?ect of TiO2 on the N2 selectivity of CeMnOx catalyst. Results indicated that loading TiO2 weakened the redox ability and enhanced the NH3 adsorption ability of CeMnOx catalyst, and thus inhibited NO/NH3 oxidation and facilitated the Eley?Rideal reaction pathways even at higher temperature.
关键词： TiO2,NH3 adsorption,redox ability,CeMnOx catalyst,N2 selectivity,NH3-SCR
更新于2025-09-11 14:15:04
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Catalyst‐Free Vapor–Solid Deposition Growth of β‐Ga <sub/>2</sub> O <sub/>3</sub> Nanowires for DUV Photodetector and Image Sensor Application
摘要： Photodetection in the solar-blind deep-ultraviolet (DUV) regime (200–280 nm) has received significant attention for its many critical applications in military and civil areas. In this study, a vapor–solid synthesis technique for catalyst-free growth of single-crystalline β-Ga2O3 nanowires is developed. A photodetector made of the nanowires is highly sensitive to 265 nm DUV illumination with excellent photoresponse performance. The performance parameters including Ilight/Idark ratio, responsivity, specific detectivity and response speed can attain ≈103, ≈233 A W?1, ≈8.16 × 1012 Jones, and 0.48/0.04 s, respectively. Additionally, the detector has an abrupt response cutoff wavelength at ≈290 nm with a reasonable DUV/visible (250–405 nm) rejection ratio exceeding 102. It is also found that the device can operate properly at a large applied bias of 200 V with the responsivity being enhanced to as high as ≈1680 A W?1. Moreover, such a nanowires-based photodetector can function as a DUV light image sensor with a reasonable spatial resolution. Holding the above advantages, the present DUV photodetector based on catalyst-free grown β-Ga2O3 nanowires possesses huge possibility for application in future DUV optoelectronics.
关键词： DUV photodetectors,catalyst-free growth,nanowires,image sensors,β-Ga2O3
更新于2025-09-11 14:15:04
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A Novel Anion Doping for Stable CsPbI <sub/>2</sub> Br Perovskite Solar Cells with an Efficiency of 15.56% and an Open Circuit Voltage of 1.30 V
摘要： Currently, the efficient preparation of imines is still a great challenge under mild conditions. In this article, by incorporating 2-acetylpyridine thiosemicarbazone (HL), Co(NO3)2·6H2O and Na2MoO4·2H2O, a new compound [Co(L)2]2[Mo6O19] (1) was prepared and characterized by elemental analysis (EA), infrared (IR) spectra, ultraviolet–visible (UV–Vis) spectra, powder X-ray diffractometry (PXRD) spectra, X-ray photoelectron spectroscopy (XPS) and X-ray single-crystal diffraction. 1 could be used as a heterogeneous catalyst for oxidative coupling of amines in a comparatively mild condition. Furthermore, 1 exhibited remarkable catalytic performance for oxidation coupling of amines to imines with high yield in the presence of tert-butyl hydroperoxide (TBHP) (up to 92%). Kinetic measurements of the oxidation of benzylamine suggest that the rate law is r = k′[BnNH2][TBHP] (k′ = k[cat] = 0.2338 L mol?1 h?1). Additionally, 1 can be recycled at least three times without a distinct loss of activity.
关键词： Isopolyoxometalate,Heterogeneous catalyst,Imines,Oxidation
更新于2025-09-11 14:15:04
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Dynamics Contributions to the Growth Mechanism of Ga2O3 Thin Film and NWs Enabled by Ag Catalyst
摘要： In the last few years, interest in the use of gallium oxide (Ga2O3) as a semiconductor for high power/high temperature devices and UV nano-sensors has grown. Ga2O3 has an enormous band gap of 4.8 eV, which makes it well suited for applications in harsh environments. In this work, we explored the effect of Ag thin film as a catalyst to grow gallium oxide. The growth of gallium oxide thin film and nanowires can be achieved by heating and oxidizing pure gallium at high temperatures (~1000 °C) in the presence of trace amounts of oxygen. We present the results of structural, morphological, and elemental characterization of the β-Ga2O3 thin film and nanowires. In addition, we explore and compare the sensing properties of the β-Ga2O3 thin film and nanowires for UV detection. The proposed process can be optimized to a high scale production Ga2O3 nanocrystalline thin film and nanowires. By using Ag thin film as a catalyst, we can control the growth parameters to obtain either nanocrystalline thin film or nanowires.
关键词： Ga2O3,thermal oxidation,nanowires,thin film,silver catalyst,quartz
更新于2025-09-11 14:15:04
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Additional obstacles in carbon nanotube growth by gas-flow directed chemical vapour deposition unveiled through improving growth density
摘要： Here, we demonstrate an approach of increasing the density of ultralong carbon nanotubes (CNTs) growth by combining fast-heating method developed by Huang et al. (J. Am. Chem. Soc., 2003, 125, 5636–5637) with catalyst support engineering. Specifically, using graphene oxide as a catalyst support for iron oxide (Fe3O4) catalyst nanoparticles, we achieved high density growth of CNTs grown by the “kite-mechanism”. Our analysis revealed that the fast-heating method reduced undesired aggregation of the catalyst nanoparticles, which has been reported to be a primary limiation mechanism, by shortening the time between substrate heating and CNT growth. In addition, the use of graphene oxide support worked to controllably and uniformly disperse catalyst nanoparticles in relatively high density which provided increased process control by extending the time before the onset of catalyst aggregation. Together, these approaches suppressed the aggregation of the catalyst nanoparticles, which facilitated the “tip-growth” mode instead of “root-growth” mode, and led to the high density growth of ultralong CNTs. Our results also indicate additional limitations and complexities on the high density CNT growth by the kite-growth approach, which limit high density synthesis.
关键词： graphene oxide,catalyst support engineering,fast-heating method,carbon nanotubes,chemical vapour deposition
更新于2025-09-11 14:15:04
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Catalyst-Free Selective Oxidation of Diverse Olefins to Carbonyls in High Yield Enabled by Light under Mild Conditions
摘要： The selective oxidation of ole?ns, in particular, aromatic ole?ns to carbonyls, is of signi?cance in organic synthesis. In general, stoichiometric toxic oxidants or a high-cost catalyst is required. Herein we report a novel and practical light-enabled protocol for the synthesis of carbonlys in high yield through a catalyst-free oxidation of ole?ns using H2O2 as a clean oxidant. A broad scope of carbonyls can be synthesized in high yield, and no catalyst or toxic oxidant is required.
关键词： light-enabled,ole?ns,carbonyls,selective oxidation,H2O2,catalyst-free
更新于2025-09-11 14:15:04
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Efficient ambient-air-stable HTM-free carbon-based perovskite solar cells with hybrid 2D–3D lead halide photoabsorbers
摘要： The title reaction has been established, which offers a useful method for the construction of dihydrocoumarin frameworks in generally good chemical yields (up to 99%) and high diastereoselectivities (up to >95 : 5 dr). This reaction represents a good example of [4 + 2] cyclizations of para-quinone methide derivatives with electron-rich reaction partners under catalyst-free conditions.
关键词： [4 + 2] cyclization,dihydrocoumarin frameworks,Catalyst-free,para-quinone methide derivatives,homophthalic anhydrides
更新于2025-09-11 14:15:04
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Recycled fiber derived carbon dispersed Ag nanoparticles as high-performance catalyst for 4-nitrophenol reduction and substrate for surface-enhanced Raman scattering
摘要： Hydroxyl-rich waste fibers have been utilized as support to synthesize paper derived monodispersed Ag composites. We utilized the one-step thermal reduction and carbonization method to synthesize a meso-pore carbon frame with mono-dispersed silver nanoparticles (Ag@C). The Ag@C showed excellent catalytic activity in 4-nitrophenol reduction reactions attributing to their well dispersed silver nanoparticles and high surface area. The Ag@C catalyst could be recycled for ten times without significant loss of its catalytic activity. Furthermore, the Ag@C could be used as a Surface-enhanced Raman scattering (SERS) substrate, and the SERS signals strength were shown to be seven times higher than unloaded carbon membrane. The results clearly indicated that the Ag nanoparticle-loaded recycled fibers exhibited SERS activity, rendering it an excellent SERS substrate for practical applications. The efficient utilization of the widely accessible waste fibers from paper-making industry could provide a sustainable feature of this work to reduce manufacturing cost and contribute it to be an environment-friendly bifunctional material.
关键词： SERS,Composites,Catalyst,Ag nanoparticles,Recycled fibers
更新于2025-09-11 14:15:04
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Single titanium-oxide species implanted in 2D g-C3N4 matrix as a highly efficient visible-light CO2 reduction photocatalyst
摘要： A visible-light-response, efficient and robust photo-catalyst for CO2 reduction is highly desirable. Herein, we demonstrate that single titanium-oxide species implanted in two-dimensional (2D) graphitic carbon nitride (g-C3N4) matrix (2D TiO-CN) can efficiently photo-catalyze the reduction of CO2 to CO under the irradiation of visible light. The synergistic interaction between single titanium oxide species and g-C3N4 in 2D TiO-CN not only enhances the separation of photo-excited charges, but also results in visible light response of single titanium-oxide species, realizing high activity of CO2 photo-reduction with extremely high CO generation rate of 283.9 μmol·h?1·g?1, 5.7, 6.8 and 292.2 times larger than those of TiO2/CN hybrid material, CN and commercial TiO2, respectively. Time-resolved fluorescence and electron spin resonance spectroscopy revealed the catalytic mechanism of the fabricated 2D TiO-CN photocatalysts for CO2 reduction.
关键词： two-dimensional (2D) photocatalysts,graphitic carbon nitride,visible-light,single atom catalyst,CO2 reduction
更新于2025-09-11 14:15:04
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Solar Light Induced Photon-Assisted Synthesis of TiO2 Supported Highly Dispersed Ru Nanoparticle Catalysts
摘要： Ru/TiO2 are promising heterogeneous catalysts in different key-reactions taking place in the catalytic conversion of biomass towards fuel additives, biofuels, or biochemicals. TiO2 supported highly dispersed nanometric-size metallic Ru catalysts were prepared at room temperature via a solar light induced photon-assisted one-step synthesis in liquid phase, far smaller Ru nanoparticles with sharper size distribution being synthesized when compared to the catalysts that were prepared by impregnation with thermal reduction in hydrogen. The underlying strategy is based on the redox photoactivity of the TiO2 semi-conductor support under solar light for allowing the reduction of metal ions pre-adsorbed at the host surface by photogenerated electrons from the conduction band of the semi-conductor in order to get a ?ne control in terms of size distribution and dispersion, with no need of chemical reductant, ?nal thermal treatment, or external hydrogen. Whether acetylacetonate or chloride was used as precursor, 0.6 nm sub-nanometric metallic Ru particles were synthesized on TiO2 with a sharp size distribution at a low loading of 0.5 wt.%. Using the chloride precursor was necessary for preparing Ru/TiO2 catalysts with a 0.8 nm sub-nanometric mean particle size at 5 wt.% loading, achieved in basic conditions for bene?tting from the enhanced adsorption between the positively-charged chloro-complexes and the negatively-charged TiO2 surface. Remarkably, within the 0.5–5 wt.% range, the Ru content had only a slight in?uence on the sub-nanometric particle size distribution, thanks to the implementation of suitable photo-assisted synthesis conditions. We demonstrated further that a ?ne control of the metal Ru nanoparticle size on the TiO2 support was possible via a controlled nanocluster growth under irradiation, while the nanoparticles revealed a good resistance to thermal sintering.
关键词： highly dispersed Ru nanoparticle,sub-nanometric particle size distribution,catalyst preparation,reaction mechanism,Ru/TiO2 catalyst,photodeposition,photon-assisted synthesis
更新于2025-09-10 09:29:36