- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Metal-organic Frameworks Derived Porous Cake-like TiO2 as an Efficient Scattering Layer for Dye-Sensitized Solar Cells
摘要： Porous anatase cake-like TiO2 was prepared by annealing Ti-based metal-organic frameworks (MOFs) MIL-125, which was then used as an efficient scattering layer in dye-sensitized solar cells (DSSCs). The morphology and structure of the prepared porous cake-like TiO2 were characterized by SEM, TEM, and XRD. DSSCs with porous cake-like TiO2 as an efficient scattering layer exhibited a photoelectric conversion efficiency (PCE) of 6.91%, which was greater than that of single P25 TiO2 based DSSCs (3.89%). The improved photoelectric conversion efficiency was attributed to the crucial role of porous cake-like TiO2 in promoting surface area and incident light scattering performance, as demonstrated by N2 adsorption/desorption isotherm analysis, diffuse reflectance spectroscopy, incident photon-to-current efficiency (IPCE) analysis, and electrochemical impedance spectroscopy (EIS).
关键词： MOFs,DSSCs,Porous cake-like TiO2,Light scattering layer
更新于2025-09-11 14:15:04
-
A comprehensive experimental characterisation of a novel porous media combustion-based thermophotovoltaic system with controlled emission
摘要： The high temperatures of combustion systems make them suitable for coupling with thermophotovoltaic systems. In practice, it is quite challenging to reduce heat losses and the spectral mismatch between the emission of the combustion source and the spectral response of photovoltaic (PV) cells. In an effort to pull these disparate energy-focussed research fields together, this paper explores the use of a low-cost erbia (Er2O3) coating on a novel porous media combustion-based thermophotovoltaic (PMC-TPV) reactor for continuous combined heat and power generation. In this work, three different configurations were analysed, including a non-coated porous foam, a coated porous foam, and a coated quartz container. As such, this study provides the first in-depth analysis and characterisation of all salient components of a PMC-TPV system. It includes a detailed characterisation of a 24-cell gallium antimonide (GaSb) array, which was attached to a heat sink and used to harvest the radiant emission from a hot (> 1200 °C), yttria-stabilised zirconia/alumina composite (YZA) ceramic foam. Since the ceramic foam does not have an ideal emissivity curve for these cells, the ability of the erbia coating to control the spectral emission was measured. The results show that by applying the erbia coating to the outer surface of the YZA foam (e.g. using a simple 2-step process of dip coating followed by curing/calcination), it is possible to increase performance, achieving a maximum in-band emission fraction of 25.4% at a firing rate of 1300 kW/m2 (i.e. around 10% of increase than that for non-coated configuration), which provides a temperature of 1285 °C. Additionally, a maximum power output of 1 W was achieved by using erbia coating on YZA foam. For the third configuration, the use of the erbia coating on the quartz tube (instead of the YZA foam) leads to an increase in the maximum core temperature of the reactor up to 1443 °C; however, this also leads to a decrease in electrical performance due to a lower in-band fraction. These findings show that applying an erbia coating on an industrial radiant emitter could enable a combined heat and power processes to gain around 30% increase of electrical output. Finally, since the PV fill factor was lower than expected, and electroluminescence measurements indicated cell damage, these findings also reveal the importance of continuously monitoring PV parameters in PMC-TPV systems.
关键词： Thermophotovoltaic systems,Direct energy conversion,Porous media combustion
更新于2025-09-11 14:15:04
-
Porous SiC-mullite ceramics with high flexural strength and gas permeability prepared from photovoltaic silicon waste
摘要： In this paper, porous SiC-mullite ceramics (PSMCs) with high ?exural strength and gas permeability were prepared with various mass fractions of MoO3 and Al2O3. Higher performance was achieved at low sintering temperatures and the problem of large amounts of cristobalite phase in the PSMCs was solved. The results show that 4 wt% MoO3 is optimal for the growth of mullite rods at a sintering temperature of 850 °C. Porosity was e?ectively controlled by the formation of interlocking structure and mechanical strength was not obviously a?ected. Therefore, the optimal content of Al2O3 was 25 wt% in samples prepared at 850–1200 °C, as the ?exural strength was generally higher than that in samples with other Al2O3 contents. The highest ?exural strength of 66.02 MPa was achieved at an open porosity of 45.4%, gas permeability of 2.32 × 10?13 m2, and permeance of 4.62 × 10?5 mol m?2 s?1 Pa?1 in samples sintered at 1000 °C. This work is of signi?cance for the industrial preparation of PSMCs from photovoltaic silicon waste.
关键词： MoO3,Photovoltaic solid waste,Porous SiC ceramic,Mullite
更新于2025-09-11 14:15:04
-
Manganese oxide nanofoam prepared by pulsed laser deposition for high performance supercapacitor electrodes
摘要： Manganese oxide nanofoam has been prepared by pulsed laser deposition, from a metallic Mn target in a 5 Torr pressure O2 buffer atmosphere. The as-prepared samples were heat-treated at different temperatures (300?C-500?C) in air. Both as-deposited and heat-treated samples have a high porosity foam-like morphology, as shown by Field Emission Scanning Electron Microscopy. High Resolution Transmission Electron Microscopy revealed that the nanofoam is composed by linked nanoparticles with slight crystallization and growth of the nanoparticles due to heat-treatment, which was confirmed by X-ray diffraction, Raman Spectroscopy and X-ray Photoelectron Spectroscopy. These techniques also showed a variable oxide composition upon heat treatment. The supercapacitive properties of manganese oxide nanofoam treated at 300?C exhibited a specific capacitance higher than 1000 F/g, in the 0 to +1.0 V potential range. After heat treatment at 400?C and 500?C, the specific capacitance decreased compared to that of the 300?C treated sample. An increase of about 130% in the initial capacitance was obtained after 500 cycles for this sample. However, it decreases to one third of the maximum value after 5000 cycles. The results shows that the obtained manganese oxide nanofoam has very high specific capacitance but need to improve the cycle stability.
关键词： microstructures,pulsed laser deposition,porous materials,supercapacitors,nanofoam,manganese oxides
更新于2025-09-11 14:15:04
-
High-performance and -stability graphene quantum dots-mixed conducting polymer/porous Si hybrid solar cells with titanium oxide passivation layer
摘要： Recently, conducting polymer/Si hybrid solar cells (HSCs) based on simple fabrication processes are highly attractive due to their low cost, but low conductivity of the polymer, high reflection index of Si, and large recombination loss on the Si back contact are major drawbacks that should be solved for the practical applications. Here, we first report HSCs composed of graphene quantum dots (GQDs)-mixed poly (3,4-ethylenedioxythiophene) (PEDOT:GQDs)/porous Si (PSi)/n-Si/titanium oxide (TiOx, back passivation layer). Maximum power conversion efficiency (PCE) of 10.49 % is obtained from the HSCs at an active area of 5 mm2, resulting from the enhanced conductivity of the PEDOT:GQDs, the reduced reflectivity of Si (the increased absorption) by the formation of PSi, and the prevented recombination loss at the Si backside due to the passivation. In addition, the HSCs of 16 mm2 active area maintain ~78 % (absolutely from 8.03 to 6.28 %) of the initial PCE even while kept under ambient conditions for 15 days.
关键词： conducting polymer,passivation,hybrid solar cell,titanium oxide,porous Si,reflectivity,graphene quantum dot
更新于2025-09-11 14:15:04
-
High Sensitivity Detection of Copper Ions in Oysters Based on the Fluorescence Property of Cadmium Selenide Quantum Dots
摘要： Enhancing the mass transport from the flow field side to the membrane side without sacrificing the active surface area is a critical strategy for the design of electrodes in flow-field structured vanadium redox flow batteries (VRFBs). In this work, we design and prepare a novel porous electrode with a gradient distribution in pores, enabling a gradual decrease in permeability but an increase in active surface areas from the flow field side to the membrane side. This design not only increases the electrode utilization due to the enhanced mass transport near the flow field side, but also avoids the loss of active surface area near the membrane side. Numerical modeling results show that compared to the conventional electrode design, the gradient electrode design can promote the uniform distribution of local reaction current density and overpotential, leading to a lower charge voltage and higher discharge voltage. Experimental results show that at the current density of 240 mA cm?2, the battery with the gradient electrode design delivers a 69% higher discharge capacity than that with the conventional electrode design, demonstrating the superiority of the gradient electrode design strategy.
关键词： Gradient porous electrode,Large-scale energy storage,Mass transport,Vanadium redox flow batteries
更新于2025-09-11 14:15:04
-
Wurtzite CoO: a direct band gap oxide suitable for a photovoltaic absorber
摘要： Rational design of high-efficiency carbon-based nanomaterials towards heterogeneous activation of peroxymonosulfate (PMS) for environmental remediation is highly desirable. Codoping of Co and N into carbon may synergistically modify the electronic structure of carbon and enhance its catalytic activity towards PMS. However, the synergistic mechanism between Co and N, especially the role of Co, remains unknown. Herein, Co and N codoped porous carbons (Co–N-PCs) were constructed for enhanced PMS activation. The Co doping level was varied to study the role of Co in Co–N-PCs. Results showed that codoping of Co and N into carbon generated a synergistic effect to enhance PMS activation for the degradation of organic pollutants. The kinetic constant of phenol degradation of the Co–N-PC was 48.4, or 17.6 times larger than that of porous carbon with only N or Co doping, and was superior to that of homogeneous Co2+ (best reported PMS catalyst). Moreover, the catalytic activity of Co–N-PC was significantly enhanced with the increase of Co–N coordination sites (Co–Nx), which could also inhibit Co leaching due to its strong binding. The experimental and DFT results revealed that the synergism of Co and N was ascribed to the combination of their different roles: the N doping mainly produced the charged carbon sites for PMS adsorption, while the Co doping mainly facilitated the electron transfer from carbon to PMS for its dissociation into sulfate radical.
关键词： Co and N codoped porous carbons,peroxymonosulfate,organic pollutants,heterogeneous activation,synergistic mechanism
更新于2025-09-11 14:15:04
-
Growing high-quality CsPbBr <sub/>3</sub> by using porous CsPb <sub/>2</sub> Br <sub/>5</sub> as an intermediate: a promising light absorber in carbon-based perovskite solar cells
摘要： CsPbBr3 with a large band gap ((cid:1)2.3 eV) is a promising material for fabricating perovskite solar cells (PSCs) with a high open-circuit voltage (Voc) and high stability. However, a suitable method is still lacking for depositing high-quality CsPbBr3 films. Herein, we develop a novel strategy to deposit high-quality CsPbBr3 films by employing a porous CsPb2Br5 film as an intermediate layer. Highly porous CsPb2Br5 films composed of lamellar crystals were obtained by immersing Pb–Br precursor layers in a low-concentration CsBr IPA solution. The low CsBr concentration helped to widen the processing window of CsPb2Br5, while the low-polarity IPA solvent served to keep the film structure stable during the reaction. High-quality CsPbBr3 films with full coverage, high purity and low defect density were obtained by further converting the CsPb2Br5 films in a high-concentration CsBr solution. After introducing the optimized CsPbBr3 film into a carbon-based PSC without a hole transporting material (C-PSC), a power conversion efficiency (PCE) of 6.1% and a Voc of 1.38 V were achieved. Moreover, the devices without encapsulation show almost no PCE decay after 200 days of storage in ambient air (25–85% relative humidity, 20–30 (cid:3)C) and at 80 (cid:3)C (10–20% relative humidity) for over 1080 h.
关键词： CsPbBr3,perovskite solar cells,stability,porous CsPb2Br5,carbon-based
更新于2025-09-11 14:15:04
-
Preparation of hexagonal micro-sized α-Al2O3 platelets from a milled Al(OH)3 precursor with NH4F and NH4Cl additives
摘要： In the present work, an Ni5P4/Ni porous composite with a Ni foam as the skeleton was prepared through phosphorization calcination at 500 1C. Meanwhile, the catalytic activity of the as-prepared Ni5P4/Ni porous composite was explored for the treatment of a large-volume e?uent with a high concentration of 4-nitrophenol at room temperature. At last, the catalytic mechanism was discussed preliminarily. The results indicated that the Ni5P4/Ni porous composite possessed remarkable catalytic activity for the borohydride-assisted reduction of 4-nitrophenol. When the concentration of 4-nitrophenol was 1.0 (cid:2) 10(cid:3)3 mol L(cid:3)1, the catalytic reduction e?ciency of 4-nitrophenol was up to 99% within 13 min over the aforementioned sample. More interestingly, it was suitable for the treatment of a large-volume e?uent with a high concentration of 4-nitrophenol. Almost 99% of 4-nitrophenol (1.0 (cid:2) 10(cid:3)2 mol L(cid:3)1, 100 mL) could be removed within 30 min. Even when 4-nitrophenol was near saturation in water (5.0 (cid:2) 10(cid:3)2 mol L(cid:3)1), 4-nitrophenol could still be removed absolutely from water after a 165 min reaction in the presence of the Ni5P4/Ni porous composite. In the catalytic process, Ni5P4 could serve as the active sites and accelerate the formation of hydrogen atoms from BH4(cid:3). Meanwhile, the Ni skeleton could make the electron transfer faster in the catalytic system. Besides, the macroporous structure of the sample also played an important role in the catalysis process.
关键词： room temperature,large-volume effluent,4-nitrophenol,catalytic reduction,Ni5P4/Ni porous composite
更新于2025-09-11 14:15:04
-
End-pump high efficiency 355 nm laser with a convex–concave cavity and optically-uncoated Brewster angle-cut LiB <sub/>3</sub> O <sub/>5</sub> crystal
摘要： Porous organic polymers (POPs), with features of permanent nanopores and designable frameworks, show great promise as sulfur host materials to restrain the shuttling of polysulfides, one of the main obstacles in the development of lithium–sulfur batteries. However, the simple physical entrapment from weak intermolecular interactions via a typical melt-diffusion method results in the diffusive loss of polysulfides that has thus far restricted their potential. Herein, a facile strategy for introducing chemical covalent interactions between POPs and sulfur via the regulation of sulfur infiltration temperature is reported. The results show that increasing the temperature to a suitable value, e.g., 400 °C, for a fluorinated triazine-based framework (FCTF), enables chemical bonding between the sulfur and aromatic FCTF backbone. Benefitting from the synergetic chemical and physical confinement effect, the shuttling of polysulfides can be efficiently restrained. As a result, the sample features superior sulfur utilization, high-rate performances, and good cycle stability, as compared with the sample with only physical confinement. The proposed strategy can also be extended to other POPs, such as the boroxine-linked covalent organic framework, by judiciously tailoring the infiltration temperatures. The findings disclose the important role of infiltration temperatures in developing efficient cathode host materials for lithium–sulfur batteries.
关键词： porous organic polymers,electrochemical performance,covalent chemical interactions,lithium–sulfur batteries,elevated sulfur infiltration temperature
更新于2025-09-11 14:15:04