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Ultrasonication-assisted synthesis of CsPbBr <sub/>3</sub> and Cs <sub/>4</sub> PbBr <sub/>6</sub> perovskite nanocrystals and their reversible transformation
摘要： We demonstrate an ultrasonication-assisted synthesis without polar solvent of CsPbBr3 and Cs4PbBr6 perovskite nanocrystals (PNCs) and their reversible transformation. The as-prepared CsPbBr3 PNCs and Cs4PbBr6 PNCs exhibit different optical properties that depend on their morphology, size, and structure. The photoluminescence (PL) emission and quantum yield (QY) of the CsPbBr3 PNCs can be tuned by changing the ultrasound power, radiation time, and the height of the vibrating spear. The optimized CsPbBr3 PNCs show a good stability and high PL QY of up to 85%. In addition, the phase transformation between CsPbBr3 PNCs and Cs4PbBr6 PNCs can be obtained through varying the amount of oleylamine (OAm) and water. The mechanism of this transformation between the CsPbBr3 PNCs and Cs4PbBr6 PNCs and their morphology change are studied, involving ions equilibrium, anisotropic growth kinetics, and CsBr-stripping process.
关键词： ultrasonication,polar-solvent-free,CsPbBr3 PNCs,Cs4PbBr6 PNCs,reversible transformation
更新于2025-11-19 16:46:39
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In Situ Generation of AgI Quantum Dots by the Confinement of A?Supramolecular Polymer Network: A Novel Approach for Ultrasensitive Response
摘要： Currently, it is difficult to realize environmentally friendly synthesis of zeolites due to the use of the solvent. Therefore, it is of great importance to realize zeolite synthesis from iron ore tailings (IOTs) by a solvent-free method. In this work, in situ formed zeolite crystals are self-assembled and IOTs are converted into hierarchically porous ZSM-5. After that, the products prepared are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption. The results demonstrate that the samples show well-defined crystallinity and have micro-/mesoporous structures. The BET surface area is estimated to be 319.809 m2 g?1 and the external surface area is 92.693 m2 g?1, which indicate the as-synthesized ZSM-5 is a good hierarchically porous material. This work provides a reference for green synthesis of hierarchically porous ZSM-5 from IOT.
关键词： Hierarchical structure,Iron ore tailings,Solvent-free method,ZSM-5
更新于2025-11-14 15:15:56
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Solvent-free Method to Encapsulate Polyoxometalate into Metal-Organic Frameworks as Efficient and Recyclable Photocatalyst for Harmful Sulfamethazine Degrading in Water
摘要： Through a less-investigated in-situ hot-pressing synthesis method, the phosphotungstic acid H3PW12O40 (denoted as PW12) was rapidly incorporated into a metal-organic framework MFM-300(In) in a short time, affording novel PW12@MFM-300(In) composites. This solvent-free preparation process is not only environment-friendly but also energy/time-saving. The inclusion of PW12 in MFM-300(In) was demonstrated by different physical and chemical characterizations. It was interesting to find that PW12@MFM-300(In) as new heterocatalysts display synergistic activity for the visible-light-driven catalytic degradation of pharmaceutically active compound sulfamethazine (SMT). 4-PW12@MFM-300(In) with excellent robustness possesses the high removal efficiency of about 98% toward SMT within 2 h at room temperature, and can also be recycled multiple times for this catalytic process.
关键词： polyoxometalate,metal-organic framework,solvent-free,sulfamethazine,photocatalytic materials
更新于2025-09-23 15:23:52
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Fabrication of UV-curable solvent-free epoxy modified silicone resin coating with high transparency and low volume shrinkage
摘要： A type of solvent-free transparent epoxy modified silicone resin coating with high transparency and low volume shrinkage was produced by UV curing method. The features of the UV curing process were studied. The performances of the silicone coating obtained such as transparency, thermal stability and the volume shrinkage were also investigated in detail, which expressed that the materials obtained were with good thermal stability, good adhesive ability and fairly low volume shrinkage.
关键词： UV curing,Transparent coating,Epoxy modified silicone resin,Solvent-Free
更新于2025-09-23 15:22:29
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Full Efficiency Recovery in Hole-Transporting Layer-Free Perovskite Solar Cells With Free-Standing Dry-Carbon Top-Contacts
摘要： Carbon-based top electrodes for hole-transporting-layer-free perovskite solar cells (PSCs) were made by hot press (HP) transfer of a free-standing carbon-aluminum foil at 100?C and at a pressure of 0.1 MPa on a methylammonium lead iodide (MAPbI3) layer. Under these conditions, the perovskite surface was preserved from interaction with the solvent. Over a timescale of 90 days, HP-PSCs were systematically compared to reference cells with carbon-based top electrodes deposited by doctor blading (DB). We found that all the photovoltaic parameters recorded in HP-PSCs during time under ambient conditions settled on values systematically higher than those measured in the reference DB-PSCs, with ef?ciency stabilized at around 6% within the ?rst few measurements. On the other hand, in DB-PSCs, a long-lasting (～14 days) degrading transient of the performances was observed, with a loss of ef?ciency from an initial ～8% to ～3%. Moreover, in HP-PSCs, a systematic day-by-day recovery of the ef?ciency after operation was observed (1～2%) by leaving the cell under open circuit, a nitrogen environment, and dark conditions. Noteworthily, a full recovery of all the parameters was observed at the end of the experiment, while DB-PSCs showed only a partial recovery under the same conditions. Hence, the complete release of solvent from the carbon contact, before an interface is established with the perovskite layer, offers a de?nite advantage through the long period of operation in preventing irreversible degradation. Our ?ndings indeed highlight the crucial role of the interfaces and their feasible preservation under nitrogen atmosphere.
关键词： durability,healing,self-curing,MAPbI3,solvent-free,stability,nitrogen
更新于2025-09-23 15:19:57
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Solvent-free and large-scale preparation of silver@polypyrrole core@shell nanocomposites; structural properties and terahertz spectroscopic studies
摘要： There is a growing interest over the environmental safety and mass-production of polymer nanocomposites. Solvent-free synthetic pathways are considered as promising alternative green techniques because of their high efficiency, simplicity and negligible liberation of hazardous waste. A new synthetic route has been developed to synthesize silver@polypyrrole core@shell nanocomposites at ambient condition. The silver nanoparticles are directly synthesized via solid-state reaction with poly(vinylpyrrolidone) and then pyrrole is polymerized in Ag/PVP powder. The band gap value decreases with the increased addition of pyrrole in the preparation step due to the formation of more silver nanoparticles. Scanning and transmission electron microscope confirm the formation of core@shell structure. The negatively charged carbonyl group of poly(vinylpyrrolidone) can bind to polycationic polypyrrole by an electrostatic effect to form the core@shell structure. The terahertz spectroscopy characterizes the prepared core@shell nanocomposites that are well fit to the Drude-Smith model. The DC optical conductivity in the terahertz range (0.3–2 THz) is increased with increasing Py addition.
关键词： Core@shell,Solvent-free method,Silver,Polypyrrole,Optical conductivity
更新于2025-09-19 17:13:59
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Low-temperature Synthesized Nba??doped TiO <sub/>2</sub> Electron Transport Layer enabling High-efficiency Perovskite Solar Cells by Band Alignment Tuning
摘要： An Nb-doped TiO2 (Nb-TiO2) film comprising a double structure stacked with a bottom compact layer and top mesoporous layers was synthesized by treating a Ti precursor-coated substrate using a one-step low-temperature steam-annealing (SA) method. SA-based Nb-TiO2 films possess high crystallinity and conductivity, and that allows better control over the conduction band (CB) of the TiO2 for electron transport layer (ETL) of the perovskite solar cells (PSCs) by the Nb doping level. Optimization of power conversion efficiency (PCE) for the Nb-TiO2 based ETL was combined with CB level tuning of the mixed-halide perovskite by changing the Br/I ratio. This band offset management enabled to establish the most suitable energy levels between ETL and perovskites. This method was applied to reduce the bandgap of perovskite to enhance photocurrent density while maintaining a high open-circuit voltage. As a result, the optimal combination of 5 mol% Nb-TiO2 ETL and 10 mol%-Br in the mixed-halide perovskite exhibited high photovoltaic performance for low-temperature device fabrication, achieving a high yield PCE of 21.3%.
关键词： low-temperature process,solvent-free hydrothermal synthesis,electron transport layer,steam-annealing method,Perovskite solar cell,niobium-doped TiO2
更新于2025-09-19 17:13:59
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1000 h Operational Lifetime Perovskite Solar Cells by Ambient Melting Encapsulation
摘要： Improving device lifetime is one of the critical challenges for the practical use of metal halide perovskite solar cells (PSCs), wherein a reliable encapsulation is indispensable. Herein, based on an in-depth understanding of the degradation mechanism for the PSCs, a solvent-free and low-temperature melting encapsulation technique, by employing low-cost paraffin as the encapsulant that is compatible with perovskite absorbers, is demonstrated. The encapsulation strategy enables the full encapsulating operations to be undertaken under an ambient environment. It is found that the strategy not only removes residual oxygen and moisture to prevent the perovskite from phase segregation, but also suppresses the species volatilization to impede absorber decomposition, enabling a PSC devices with good thermal and moisture stability. As a result, the as-encapsulated PSCs achieve a 1000 h operational lifetime for the encapsulated device at continuous maximum power point output under an ambient environment. This work paves the way for scalable and robust encapsulation strategy feasible to hybrid perovskite optoelectronics in an economic manner.
关键词： stability,perovskite solar cells,solvent-free,ambient encapsulation,low-temperature
更新于2025-09-16 10:30:52
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Efficient Anti-solvent-free Spin-Coated and Printed Sn-Perovskite Solar Cells with Crystal-Based Precursor Solutions
摘要： The existence of a mass oxidation of Sn2+ that takes place mainly during preparation of precursor solutions and fabrication of films creates a lead-free solar cell of low open-circuit voltage, which leads to low PCE. To reduce the oxidation process, we employed an innovative crystal fabrication method with anti-solvent-free recrystallization technology. As a result, to the best of our knowledge, both spin-coated and printed lead-free solar cells based on FASnI3 achieved the highest 3D-based PCE to date.
关键词： FASnI3,anti-solvent-free method,lead-free solar cells,PCE,single crystals
更新于2025-09-11 14:15:04
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Effect of titanium (IV) isopropoxide molarity on the crystallinity and photocatalytic activity of titanium dioxide thin film deposited via green sol–gel route
摘要： In this paper, the effect of titanium (IV) isopropoxide TTIP molarity on the crystallinity and TiO2 thin film properties deposited via green sol–gel route was reported. The green sol–gel route is a pioneering approach for eco-friendly coating where solvent is not utilized in the sol formulation. This is in contrast to the common TiO2 sol formulation where solvent is used despite the long term harmful the environment. TiO2 solution with different TTIP molarity of 0.2 M, 0.3 M, 0.4 M and 0.5 M were utilized during coating deposition. Deposition were conducted for ten times using dip coating and treated at 500 ?C (1-h). The crystalline phases and phase content were characterized using X-ray diffraction (XRD) and reference intensity ratio (RIR) equation. Crystallites size was obtained by Scherrer’s equation while coating morphologies was analyzed using scanning electron microscope (SEM). The photocatalytic activity was conducted by the degradation of methylene blue (MB) towards UV-light and visible light. At higher TTIP molarity (0.5 M), higher crystallinity of mixed anatase (～17 nm) and rutile (～29 nm) phases were obtained along with homogeneous coating (cracking and visible pore). Also, higher MB degradation were obtained at UV-light (95%) and visible-light (86%) irradiation. In conclusion, higher TTIP molarity produced TiO2 film with higher crystallinity, small crystallite size, cracking morphology thus contribute good performance in photocatalytic activity. Findings in this work shown that TiO2 thin film deposition is possible conducted without the use of solvent through optimized formulation of only precursor, acid and water. This is beneficial for the environment sustainability.
关键词： Sol–gel dipping,Titanium dioxide,Green route,Solvent free,Titanium (IV) isopropoxide,Photocatalytic activity
更新于2025-09-10 09:29:36