- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Atomic-thick TiO <sub/>2</sub> (B) nanosheets decorated with ultrafine Co <sub/>3</sub> O <sub/>4</sub> nanocrystals as a highly efficient catalyst for lithium-oxygen battery
摘要： Development of high efficient catalysts based on transition metal oxides (TMOs) is desirable, and remains a big challenge for lithium-oxygen (Li-O2) batteries. In the present work, atomic-thick TiO2(B) nanosheets decorated with ultrafine Co3O4 nanocrystals (Co3O4-TiO2(B)) was synthesized and utilized as cathode catalyst in Li-O2 batteries by designing a hybrid and inducing oxygen vacancies. The XPS characterization results suggested that the introduction of Co3O4 nanocrystals could induce numerous oxygen vacancies in the TiO2(B) nanosheets through Co doping in the hybrid catalyst. The subsequent electrochemical experiments indicated that the Li-O2 batteries with the prepared hybrid catalysts showed high specific capacity (11000 mAhg-1), and good cycling stability (200 cycles at a limited capacity of 1000mAhg-1) with low polarization (above 2.7V for discharge medium voltage and below 4.0V for charge medium voltage within 80 cycles). Furthermore, a possible working mechanism was proposed for a better understanding of the high performance of Co3O4-TiO2(B) catalysts for the Li-O2 batteries. This work also provided some new insights into designing efficient catalysts through interface engineering between 2D (two dimentional) TMOs and 0D (zero dimentional) TMOs for Li-O2 batteries or other catalysis related fields.
关键词： film-like Li2O2,oxygen vacancies,TiO2(B) nanosheets,Co3O4 nanocrystals,Li-O2 battery
更新于2025-09-23 15:21:21
-
Improved Solar Energy Photoactivity over Defective BiOBr Ultrathin Nanosheets towards Pollutants Removal and Oxygen Evolution
摘要： Defective BiOBr nanosheets with ultrathin thickness and surface confined pits have been synthesized through a dual control of cetyltrimethyl ammonium bromide (CTAB) and polyvinyl pyrrolidone (PVP). The photocatalytic activity of the obtained defective BiOBr nanosheets was evaluated for the removal of rhodamine B (RhB), ciprofloxacin (CIP) and oxygen evolution from water. The as-prepared defective BiOBr nanosheets displayed significantly increased activity for pollutant degradation and oxygen evolution. The enhanced photocatalytic activity was ascribed to the improved light harvesting, suppression of charge recombination, and an increase in the number of active sites for photocatalytic reaction. The electronic structure of the defective BiOBr ultrathin nanosheets with confined pits has been tuned and thus varied the photocatalytic mechanism for pollutant degradation. The active species have changed from hole for BiOBr nanoplates to superoxide radical (O2??) and hole for defective BiOBr nanosheets determined by ESR analysis and trapping experiments.
关键词： Ultrathin nanosheets,Solar energy,Defects,BiOBr,Photocatalytic
更新于2025-09-23 15:21:21
-
Surfactant-free Exfoliation of Multilayer Molybdenum Disulfide Nanosheets in Water
摘要： In this study, we report a potentially scalable method for producing multilayer molybdenum disulfide (MoS2) nanosheets. The addition of a small amount of ammonia solution can improve the exfoliation of MoS2 nanosheets in water. The surface charge induced by spontaneous adsorption of hydroxyl ions on MoS2 surfaces favors the exfoliation process. The edge charge generated by the ionization of edge-attached groups facilities the dispersion of exfoliated nanosheets in water. It is also found that smaller MoS2 nanosheets show an improved photocatalytic performance, which stems from enhanced edge effects and a reduced flake thickness. This work opens a new vista on preparation and application of multilayer MoS2 nanosheets.
关键词： edge effects,ammonia solution,dispersion,water,multilayer MoS2 nanosheets,exfoliation
更新于2025-09-23 15:21:21
-
Surface Modification on Nanoripple-like ZnO Nanorod Arrays Using Two-dimensional (2D) Bi2OS2 to Fabricate High-Performance Inverted Polymer Solar Cells
摘要： In this paper, three-dimensional (3D) nanoripple-like ZnO nanorod arrays (R-ZnO NRAs) are successfully fabricated and modified by two-dimensional (2D) Bi2OS2 material, and inverted polymer solar cells (IPSCs) with R-ZnO modified by Bi2OS2 as electron transmission layer (ETL) are fabricated for the first time. The results show that the surface morphologies of R-ZnO NRAs can be controlled by adjusting the concentration of the modified 2D Bi2OS2 solution. Bi2OS2 modification can not only suppress the surface defects of R-ZnO NRAs, reduce the recombination of photogenerated charges, but also increase crystallinity of the active layer, resulting in effective electron collection. And thus, the performance of IPSCs is obviously improved. The power conversion efficiency (PCE) of PTB7: PCBM based PSCs with R-ZnO NRAs modified by 2% Bi2O2S as ETL is considerably raised to 7.31% from 5.51%. More interestingly, Bi2OS2 modification enhances IPSCs stability to remain 80.9% of their initial PCE after 80 days, yet IPSCs with pristine R-ZnO NRAs remain only 47.4% of their initial PCE. Moreover, this approach can also successfully improve the performance of another IPSC composed of PBDB-T: ITIC blends. The PCE of the device based on 2% Bi2OS2-modified R-ZnO NRAs is improved to 9.94% from 8.03% of the reference device without Bi2OS2 modification. This work not only provides an effective mean of surface modification of R-ZnO NRAs, but also shows the Bi2OS2 material has potential application in PSCs.
关键词： Recombination,Bi2OS2 nanosheets,Inverted polymer solar cells,Nanoripple-like ZnO nanorod arrays
更新于2025-09-23 15:21:01
-
Photocatalytic degradation and adsorption of phenol by solvent-controlled TiO2 nanosheets assisted with H2O2 and FeCl3: Kinetic, isotherm and thermodynamic analysis
摘要： Hydrofluoric acid (HF) has been widely employed to regulate the surface characteristics of TiO2 containing sheet-like morphology with (001) facets for various environmental applications. However, carcinogenic effects associated with HF are the main stumbling blocks on its way towards global commercialization. In the same line of action, an eco-friendly approach for the synthesis of anatase TiO2 nanosheets (TNSs) via employing hydrothermal process and N, N dimethylformamide (DMF) as a novel morphology-controlling agent has been reported. The as-produced TNSs were characterized by XRD, HRTEM, Raman, FTIR, XPS and DRS characterizations. The photoactivity of as-produced TNSs was studied for photocatalytic degradation of phenol under visible light irradiation in the presence of green oxidants such as hydrogen peroxide (H2O2) and ferric chloride (FeCl3) to produce free hydroxyl radicals for speedily reduction of recombination of photogenerated electrons hole-pairs. The results revealed that as-produced TNSs could activate by green oxidants with yielding upto 94.19 and 97.12 % phenol degradation in the presence of H2O2 and FeCl3, respectively. Moreover, phenol adsorption data was well explained via pseudo first order and pseudo second order kinetics while Langmuir and Freundlich isotherms were more suitable to explain the adsorption of phenol onto TNSs, providing maximum adsorption capacity up to 23.596 mg/g. Various thermodynamic parameters were evaluated, suggesting the favourable, spontaneous and endothermic adsorption process. The values of activation energy (18.505 kJ/mol) confirmed the physical adsorption of phenol onto TNSs. The excellent aptitude of anatase TNSs to produce hydroxyl radicals and super-oxides radicals with promptly lessening of recombination of photogenerated electron hole-pairs makes them motivated applicant for wastewater treatment.
关键词： N, N dimethylformamide,green oxidants,adsorption mechanism,Hydrothermal process,TiO2 nanosheets,phenol
更新于2025-09-23 15:21:01
-
Enhanced stability of ?±-phase FAPbI3 perovskite solar cells by insertion of 2D (PEA)2PbI4 nanosheets
摘要： Methylammonium (MA) is one of the main obstacles that hold back the commercialization of perovskite solar cells (PSCs). Formamidinium (FA)-based perovskite is a promising photovoltaic material for its higher thermal stability and smaller bandgap. However, despite the introduction of Cs+ in FAPbI3, the photoactive α-phase FAPbI3 can quickly transform into a non-perovskite hexagon phase δ-FAPbI3, which limits its use in perovskite solar cell. In this work, we show the dispersed of 2D (PEA)2PbI4 nanosheets into the Cs0.1FA0.9PbI3 thin film successfully prevents the transformation of the α-phase Cs0.1FA0.9PbI3 to the δ-phase. Because of the 2D (PEA)2PbI4 nanosheets, higher quality perovskite thin-film was obtained with longer carrier lifetime, lower trap state density, and enhanced stability. The resulting device reaches a high power conversion efficiency of 20.44%, which is one of the highest for MA-free perovskites and retains 82% of their initial efficiency after 800 h aging study.
关键词： power conversion efficiency,2D perovskite nanosheets,formamidinium,stability,perovskite solar cells
更新于2025-09-23 15:21:01
-
Metallic 1T-MoS2 nanosheets and their composite materials: Preparation, properties and emerging applications
摘要： Metallic 1T phase MoS2 nanosheets and their composite materials, with unique structure and unusual properties, have attracted increasing research interest in energy conversion/storage and catalysis in the past few years. In this work, an overview of the recent progress of metallic 1T-MoS2 nanosheets and their composite materials is presented. First, we focused on the controlled synthesis of 1T-MoS2 nanosheets and their composite materials using top-down and bottom-up approaches and their unusual properties while tuning the phase structure. Then, we discussed their promising applications in energy-related areas including hydrogen evolution reaction, supercapacitors, batteries, and photocatalysis. In addition, an in-depth understanding was provided on phase tuning of these advanced materials for improved performance. Finally, the existing challenges and future research in these emerging research areas are also described.
关键词： Batteries,Hydrogen evolution reaction,Metallic 1T-MoS2 nanosheets,Properties,Photocatalysis,Supercapacitors
更新于2025-09-23 15:21:01
-
Liquid Crystalline Colloidal Mixture of Nanosheets and Rods with Dynamically Variable Length
摘要： Here, we demonstrate the novel double-component liquid crystalline colloids composed of mesogenic inorganic nanosheets and the rods with dynamically variable length controlled by temperature. As the length-controllable rod, stiff biopolymer microtubule is used, which was successfully polymerized/depolymerized from tubulin proteins through a biochemical process even in the presence of the nanosheets. The mesoscopic structure of the liquid crystal phase was reversibly modifiable as caused by the change of the rod length.
关键词： nanosheets,rods,temperature control,liquid crystalline colloids,dynamically variable length
更新于2025-09-23 15:21:01
-
Paper-Based Constant Potential Electrochemiluminescence Sensing Platform with Black Phosphorus as a Luminophore Enabled by a Perovskite Solar Cell
摘要： Exploring e?cient luminophores in the electrochemiluminescence (ECL) system is highly desired to pursue a sensitive ECL sensing platform. Herein, the black phosphorus nanosheets (BP NSs) with excellent ECL properties are investigated and serve as the luminophore with the coreactant of peroxydisulfate (S2O8 2?) solution. Moreover, owing to the overlapping of emission and absorbance spectra, e?ective resonance energy transfer (RET) is realized between the BP NSs and the introduced Au nanoparticles. In order to achieve the portable and miniaturized developing trends for the paper-based ECL sensing platform, a paper-based perovskite solar cell (PSC) device is designed to act as the power source to replace the commonly utilized expensive and cumbersome electrochemical workstation. Bene?ting from that, a PSC driven paper-based constant potential ECL-RET sensing platform is constructed, thereby realizing sensitive microRNAs (miRNAs) detection. What’s more, to attain the preferable analytical performance, the duplex-speci?c nuclease (DSN) is also introduced to assist the target recycling signal ampli?cation strategy. Based on this, highly sensitive detection of miRNA-107 with a range from 0.1 pM to 15 nM is achieved by this designed sensing platform. Most importantly, this work not only pioneers a precedent for developing a high-sensitivity PSC triggered ECL sensing platform but also explores the application prospect of BP nanomaterial in the ?eld of bioanalysis.
关键词： microRNAs detection,resonance energy transfer,perovskite solar cell,black phosphorus nanosheets,electrochemiluminescence
更新于2025-09-23 15:21:01
-
Ultrabroadband Photodetectors up to 10.6 ?μm Based on 2D Fe <sub/>3</sub> O <sub/>4</sub> Nanosheets
摘要： The ultrabroadband spectrum detection from ultraviolet (UV) to long-wavelength infrared (LWIR) is promising for diversified optoelectronic applications of imaging, sensing, and communication. However, the current LWIR-detecting devices suffer from low photoresponsivity, high cost, and cryogenic environment. Herein, a high-performance ultrabroadband photodetector is demonstrated with detecting range from UV to LWIR based on air-stable non-layered ultrathin Fe3O4 nanosheets synthesized via a space-confined chemical vapor deposition (CVD) method. Ultrahigh photoresponsivity (R) of 561.2 A W?1, external quantum efficiency (EQE) of 6.6 × 103%, and detectivity (D*) of 7.42 × 108 Jones are achieved at the wavelength of 10.6 μm. The multi-mechanism synergistic effect of photoconductive effect and bolometric effect demonstrates the high sensitivity for light with any light intensities. The outstanding device performance and complementary mixing photo response mechanisms open up new potential applications of nonlayered 2D materials for future infrared optoelectronic devices.
关键词： long-wavelength infrared,photoconductive effect,ultrabroadband photodetectors,bolometric effect,Fe3O4 nanosheets
更新于2025-09-23 15:21:01