A5046789366- nanoparticles nucleation surface interactions
- Chalcogenide Semiconductor Thin Films
- 2D Materials and Applications
- Semiconductor materials and interfaces
- Perovskite Materials and Applications
- Catalysis and Hydrodesulfurization Studies
- Machine Learning in Materials Science
- Methane Hydrates and Related Phenomena
- Silicon Nanostructures and Photoluminescence
- Semiconductor materials and devices
- MXene and MAX Phase Materials
- Photonic and Optical Devices
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Nanowire Synthesis and Applications
- Metal and Thin Film Mechanics
- Material Dynamics and Properties
- Quantum Dots Synthesis And Properties
- Catalytic Processes in Materials Science
- Graphene research and applications
- Membrane Separation Technologies
- Advanced Antenna and Metasurface Technologies
- Zeolite Catalysis and Synthesis
- Boron and Carbon Nanomaterials Research
- Poverty, Education, and Child Welfare
George Washington University
2016-2025
Kunming University of Science and Technology
2025
Northeast Agricultural University
2020-2024
Henan University
2024
Zhengzhou University
2024
State Key Laboratory on Integrated Optoelectronics
2020-2024
Jilin University
2005-2024
Nankai University
2024
Tianjin University of Finance and Economics
2024
University of Wisconsin–Madison
2024
Novel physical phenomena can emerge in low-dimensional nanomaterials. Bulk MoS2, a prototypical metal dichalcogenide, is an indirect bandgap semiconductor with negligible photoluminescence. When the MoS2 crystal thinned to monolayer, however, strong photoluminescence emerges, indicating direct transition this d-electron system. This observation shows that quantum confinement layered materials like provides new opportunities for engineering electronic structure of matter at nanoscale.
The water contact angle of nanostructured polystyrene surfaces can reach as high 162°, compared with 95° for native surfaces, and they possess a adhesion force. Surfaces coated nanotubes (see Figure) created using an alumina membrane template mimic the keratinous hairs in gecko's feet, providing large surface area through van der Waals' forces.
We present a first principle, theoretical study of MoS2 nanoparticles that provides unified explanation measured photoluminescence spectra and recent STM measurements as function size. In addition, our calculations suggest ways to engineer the electronic properties these systems so obtain direct band gap 3D layered or Mo doped metallic nanowires. particular, we show single sheet up ∼3.4 nm no appreciable quantum confinement effects. Instead, their structure is entirely dominated by surface...
We alloyed Zn2+ into CsPbI3 perovskite nanocrystals by partial substitution of Pb2+ with Zn2+, which does not change their crystalline phase. The resulting CsPb0.64Zn0.36I3 exhibited an improved, close-to-unity photoluminescence quantum yield 98.5% due to the increased radiative decay rate and decreased non-radiative rate. They also showed enhanced stability, correlated improved effective Goldschmidt tolerance factors, incorporation ions a smaller radius than ions. Simultaneously, switched...
Ideal tensile stress strain relations for single-layer MoS${}_{2}$ are investigated based on first-principle calculation, biaxial tension and uniaxial along zigzag armchair directions. The predicted ideal strengths elastic moduli in excellent agreement with the very recent experimental measurements of Bertolazzi et al. [ACS Nano 5, 9703 (2011)] Castellanos-Gomez [Adv. Mater. 24, 772 (2012)]. It is identified that strength dictated by out-of-plane soft-mode phonon instability under direction....
The long-term chemical instability and the presence of toxic Pb in otherwise stellar solar absorber APbX$_{3}$ have hindered their large-scale commercialization. Previously explored ways to achieve Pb-free halide perovskites involved replacing Pb$^{2+}$ with other similar M$^{2+}$ cations ns$^2$ electron configuration, e.g., Sn$^{2+}$ or by Bi$^{3+}$ (plus Ag$^+$), but unfortunately this showed either poor stability (M = Sn) weakly absorbing oversized indirect gaps Bi), prompting concerns...
Homogeneous ice nucleation from supercooled water was studied in the temperature range of 220–240 K through combining forward flux sampling method (Allen et al., J. Chem. Phys., 2006, 124, 024102) with molecular dynamics simulations (FFS/MD), based on a recently developed coarse-grained model (mW) (Molinero Phys. B, 2009, 113, 4008). The calculated rates display strong dependence, ranging 2.148 ± 0.635 × 1025 m−3 s−1 at 220 to 1.672 0.970 10−7 240 K. These can be fitted according classical...
Nailing down graphene's topology An electron traveling along a closed path in the momentum space of graphene crystal lattice may not end up exactly way it started. If its happens to include one special points space, will acquire phase shift. Physicists can detect signatures this process by studying transport properties graphene. Duca et al. used interferometry directly measure so-called Berry flux hexagonal optical lattice, where intersecting laser beams simulate environment that electrons...
A newly discovered group of alloys, called Gum Metals, approaches ideal strength in bulk form, exhibits significant plastic deformation prior to failure, and shows no indications conventional-dislocation activity. Two conditions must be met for a material exhibit this "ideal" behavior: (1) the stress required trigger plasticity exceed its strength, (2) intrinsically ductile when stressed strength. Metals satisfy both criteria, explaining their remarkable mechanical properties.
Solar cells based on methylammonium lead triiodide (MAPbI3) have shown remarkable progress in recent years and demonstrated efficiencies greater than 20%. However, the long-term stability of MAPbI3-based solar has yet to be achieved. Besides well-known chemical thermal instabilities, significant native ion migration halide perovskites leads current-voltage hysteresis photoinduced phase segregation. Recently, it is further revealed that, despite having excellent stability, Au electrode can...
Abstract The freezing of water typically proceeds through impurity-mediated heterogeneous nucleation. Although non-planar geometry generically exists on the surfaces ice nucleation centres, its role in remains poorly understood. Here we show that an atomically sharp, concave wedge can further promote with special geometries. Our molecular analysis shows significant enhancements emerge both when a matches lattice and such match does not exist. In particular, 45° is found to greatly enhance by...
Tungsten disulfide (WS2) is a layered transition metal dichalcogenide (TMD) that differs from other two-dimensional (2D) compounds such as graphene due to its unique semiconducting, tunable-band-gap nature. Multilayered WS2 exhibits an indirect band gap Eg of ∼1.3 eV, along with higher load-bearing ability promising for strain-tuning device applications, but the electronic properties multilayered at strain conditions (i.e., static >12%) remain open question. Here we have studied structural,...
Lead-free halide double perovskites could be useful in optoelectronic applications, such solar cells and photocatalysis. However, a comprehensive understanding of intrinsic defect properties is needed, as defects strongly affect carrier density transport. First-principles energy calculations are used to investigate representative lead-free identify deep levels. The authors show how chemical potentials the constituent elements can modified, suppress unwanted or tune Fermi level. These...
The microscopic mechanisms controlling heterogeneous ice nucleation are complex and remain poorly understood. Although good nucleators generally believed to match lattice bind water, counter examples often identified. Here we show, by advanced molecular simulations, that the of on graphitic surface is controlled coupling crystallinity hydrophilicity. Molecular level analysis reveals crystalline with an appropriate hydrophilicity may indeed template basal plane forming a strained layer, thus...
The prevalence of heterogeneous nucleation in nature was explained qualitatively by the classical theory for established over more than 60 years ago, but quantitative validity and key conclusions have remained unconfirmed. Employing forward flux sampling method coarse-grained water model (mW), we explicitly computed ice rates supercooled on a graphitic surface at various temperatures. independently calculated were found to fit well according nucleation. fitting procedure further yields...
Most ice in nature forms because of impurities which boost the exceedingly low nucleation rate pure supercooled water. However, microscopic details on these substances remain largely unknown. Here, we have unraveled molecular mechanism and kinetics formation kaolinite, a clay mineral playing key role climate science. We find that at strong supercooling presence this is about 20 orders magnitude faster than homogeneous freezing. The critical nucleus substantially smaller found for and,...
Developing engineered surfaces with scaling resistance is an effective means to inhibit surface-mediated mineral in various industries including desalination. However, contrasting results have been reported on the relationship between potential and surface hydrophilicity. In this study, we combine a theoretical analysis experimental investigation clarify effect of wetting property heterogeneous gypsum (CaSO4·2H2O) formation immersed aqueous solutions. Theoretical prediction derived from...
Abstract Objective To investigate the variations in clinical effectiveness among patients diagnosed with knee osteoarthritis who underwent intra-articular administration of platelet-rich plasma using single, triple, or quintuple injections. Methods One hundred twenty grade I-III were randomly assigned to three groups: PRP1 group, received a single injection plasma; PRP3 PRP injections one week apart; PRP5 five apart. The patients’ conditions evaluated Visual Analogue Scale (VAS) and Western...