We have obtained the first energy-resolved real-space images of filled and empty surface states Si(111)-(7\ifmmode\times\else\texttimes\fi{}7) surface, with 3-\ensuremath{'}A lateral resolution. This ability to resolve spatially these a scanning tunneling microscope depends upon new method acquire separate geometric electronic information. Our results not only are in good agreement previous spectroscopic studies but also directly reveal atomic location origin states.

The atomic structure of the Si(001) surface has been examined with use scanning tunneling microscopy (STM). STM images reveal a dimer-type reconstruction and are inconsistent chain vacancy models. Both buckled nonbuckled dimers observed, giving rise to regions (2\ifmmode\times\else\texttimes\fi{}1), c(4\ifmmode\times\else\texttimes\fi{}2), p(2\ifmmode\times\else\texttimes\fi{}2) symmetry. high density vacancy-type defects, which appear induce or stabilize buckling at room temperature. also...

Metallic WS₂ nanosheets chemically exfoliated from chemical vapour deposited nanostructures display excellent catalytic activity for the hydrogen evolution reaction.

Scanning tunneling microscopy has been used to determine the atomic structure of clean Si(001) surface. The basic structural unit reconstruction resolved with a lateral resolution \ensuremath{\sim} 3 \AA{}. Buckled and nonbuckled dimers appear be present in roughly equal amounts, indicating that they have nearly same energy. presence atomic-scale defects is discussed.

Abstract The development of efficient and robust earth‐abundant electrocatalysts for the oxygen evolution reaction (OER) is an ongoing challenge. Here, a novel stable trimetallic NiFeCr layered double hydroxide (LDH) electrocatalyst improving OER kinetics rationally designed synthesized. Electrochemical testing series LDH materials at similar catalyst loading electrochemical surface area shows that molar ratio Ni:Fe:Cr = 6:2:1 exhibits best intrinsic catalytic activity compared to other...

Hydrogen-terminated Si(111) surfaces are modified by attachment of oligodeoxynucleotides and characterized with respect to DNA surface density, chemical stability, hybridization binding specificity. Surface functionalization employs the reaction ω-unsaturated alkyl esters using UV irradiation. Cleavage ester potassium tert-butoxide yields a carboxyl-modified surface, which serves as substrate for means an electrostatically adsorbed layer polylysine thiol-modified heterobifunctional...

Violet electroluminescence is rare in both inorganic and organic light-emitting diodes (LEDs). Low-cost room-temperature solution-processed lead halide perovskites with high-efficiency color-tunable photoluminescence are promising for LEDs. Here, we report color-pure violet LEDs based on a two-dimensional perovskite material, namely, 2-phenylethylammonium (C6H5CH2CH2NH3+, PEA) bromide [(PEA)2PbBr4]. The natural quantum confinement of layered (PEA)2PbBr4 allows shorter wavelength (410 nm)...

Understanding crystal growth and improving material quality is important for semiconductors electronic, optoelectronic, photovoltaic applications. Amidst the surging interest in solar cells based on hybrid organic-inorganic lead halide perovskites exciting progress device performance, improved understanding better control of these could further boost their optoelectronic performance. Here, we report new insights perovskite materials, especially crystalline nanostructures. Specifically,...

We report the preparation and characterization of highly efficient robust photocathodes based on heterostructures chemically exfoliated metallic 1T-MoS2 planar p-type Si for solar-driven hydrogen production. Photocurrents up to 17.6 mA/cm(2) at 0 V vs reversible electrode were achieved under simulated 1 sun irradiation, excellent stability was demonstrated over long-term operation. Electrochemical impedance spectroscopy revealed low charge-transfer resistances semiconductor/catalyst...

Tunneling spectroscopy and voltage-dependent scanning tunneling microscopy have been used to study the geometry electronic properties of atomic-sized defects on Si(001) surface. Individual dimer vacancies are shown be semiconducting, consistent with π-bonded defect model Pandey. Another type characteristic is found which gives rise strongly metallic I–V characteristics, demonstrating that it has a high density states at Fermi level likely active in pinning Si(001). Spatially dependent...

We have directly observed chemisorption-induced changes in surface chemical bonding using a scanning tunneling microscope (STM). The dissociative adsorption of ${\mathrm{NH}}_{3}$ on Si(001) preserves the (2\ifmmode\times\else\texttimes\fi{}1) local symmetry, but STM images reveal spatial distribution occupied electronic states which allow us to distinguish reacted and unreacted dimers. results are interpreted terms through localized Si-H orbitals...

Higher cationic charge density on nanoparticles is correlated with higher toxicity to bacteria.

Metastable structural polymorphs can have superior properties and applications to their thermodynamically stable phases, but the rational synthesis of metastable phases is a challenge. Here, new strategy for stabilizing using surface functionalization demonstrated example formamidinium lead iodide (FAPbI3) perovskite, which at room temperature (RT) holds great promises in solar light-emitting applications. We show that, through ligand during direct solution growth RT, pure FAPbI3 cubic...

We report a facile approach to perform post-growth doping of hematite (α-Fe2O3) nanostructures by depositing titanium (Ti) precursor solution and subsequent annealing in air. Using nanowire photoanodes on fluorine doped tin oxide (FTO) glass substrates as model system, the conditions were carefully optimized highly photoactive prepared at more practically acceptable temperature 650–700 °C than ≥800 commonly used previous works. A combination microstructural characterization, elemental...

Amorphous MoS_xCl_y electrocatalyst on vertical graphene shows high catalytic performance for electrochemical and photoelectrochemical hydrogen generation.

With increasing global population, innovations in agriculture will be essential for a sustainable food supply. We compare commercial CuO NP to synthesized Cu3(PO4)2·3H2O nanosheets determine the influence of coordinating anion, particle morphology, and dissolution profile on Fusarium oxysporum f. sp. niveum induced disease watermelon. Copper organic acid solutions that mimic complexing agents found plants was increased by 2 orders magnitude relative water. showed rapid initial dissolution,...

We have developed a multistep route to the formation of covalently linked adducts single-wall carbon nanotubes (SWNT) and deoxyribonucleic acid (DNA) oligonucleotides. X-ray photoelectron spectroscopy was used characterize initial chemical modification form amine-terminated SWNTs, which were then DNA. The resulting DNA−SWNT hybridize selectively with complementary sequences, only minimal interaction noncomplementary sequences.

Although Thiobacillus ferrooxidans and Leptospirillum are widely considered to be the microorganisms that control rate of generation acid mine drainage, little is known about their natural distribution abundance. Fluorescence in situ hybridization studies showed at Iron Mountain, California, T. occurs peripheral slime-based communities (at pH over 1.3 temperature under 30 degreesC) but not important subsurface acid-forming environments (pH 0.3 0.7, degrees 50 degreesC). abundant slimes as a...

The phase diagram of vicinal Si(100) as a function misorientation angle and temperature is calculated. Contrary to previous suggestions that only double-layer steps should appear on the equilibrium surface, it predicted single-layer stepped surface at for small angles. This structure stabilized by strain relaxation thermal roughening steps. For annealed surfaces critical which transition between single- occurs calculated be...

We report a new scheme for attachment of functionalized organic molecules to polycrystalline diamond films. In this scheme, ultraviolet light is used cause local reaction between hydrogen-terminated surface and present as thin overlayer liquid film. Comparison alkenes alkanes shows that attach more efficiently. By attaching with suitable protecting groups then deprotecting after the surface, it possible prepare surfaces terminated carboxylic acid or primary amine groups. These functional may...

Quantitative measurements of adsorption from solution show up to a 70-fold increase in the coefficient when variety organic acids are adsorbed onto 6 nm compared 16 nanocrystalline titania particles. A Langmuir model modified include dependence interfacial tension (interfacial free energy) on particle size predicts an constant (Kads) as crystallite decreases, agreement with experimental results. The Kads arises predominantly increased molar surface energy rapid decreases has important...