We have developed a hierarchical nanoporous layer (HNL) on silicate glass by a simple one-pot etching method. The HNL has a three-dimensionally continuous spongelike structure with a pore size of a few tens of nanometers on its apparent surface. The pore size gradually decreases from the apparent surface to the HNL-bulk interface. This HNL bestows significant properties to glass: low optical reflectivity that reflects 7% less visible light than nontreated glass and long-persistence superhydrophilicity that keeps its water contact angle at about 5° for more than 1 year. The superhydrophilicity also realizes antifogging and antifouling functionalities.

Carbon‐black‐supported nanoparticles (CNPs) have attracted considerable attention for their intriguing catalytic properties and promising applications. The traditional liquid synthesis of CNPs commonly involves demanding operation conditions and complex pre‐ or post‐treatments, which are time consuming and energy inefficient. Herein, a rapid, scalable, and universal strategy is reported to synthesize highly dispersed metal nanoparticles embedded in a carbon matrix via microwave irradiation of carbon black with preloaded precursors. By optimizing the amount of carbon black, the microwave absorption is dramatically improved while the thermal dissipation is effectively controlled, leading to a rapid temperature increase in carbon black, ramping to 1270 K in just 6 s. The whole synthesis process requires no capping agents or surfactants, nor tedious pre‐ or post‐treatments of carbon black, showing tremendous potential for mass production. As a proof of concept, the synthesis of ultrafine Ru nanoparticles (≈2.57 nm) uniformly embedded in carbon black using this microwave heating technique is demonstrated, which displays remarkable electrocatalytic performance when used as the cathode in a Li–O2 battery. This microwave heating method can be extended to the synthesis of other nanoparticles, thereby providing a general methodology for the mass production of carbon‐supported catalytic nanoparticles.

For the investigation of nanomaterials and so-called weak-phase objects, going to lower acceleration voltages can be an advantage for several reasons: the knock-on damage [1] decreases significantly and objects displaying little to no contrast at higher voltages (weak phase objects) appear with more contrast due to their increased interaction with the sample.Full analytical capabilities considered standard for high-voltage STEM/TEMs at 30kV are expensive and typically require monochromators especially for Schottky emitter based instrumentation [1][2][3] due to the strangle-hold of the chromatic aberrations. In addition, the power supplies for lenses designed for 200/300kV contribute increasingly to the energy width of the electron beam at the low level currents needed for ≤ 30kV instrumentation. Therefore, enhancing an atomic resolution SEM with a cold field emission gun (cFEG) with STEM, EELS and diffraction capabilities provides an excellent platform for combining surface investigations typically for SEMs with high resolution and analysis capabilities of a typical STEM at comparatively low cost.Graphene as support structure for the analysis of nano-material is well established, but high quality single layer Graphene sheets remain difficult to obtain. Figure 1, left, shows a high-resolution BF STEM image of Graphene with its hexagonal structure resolved. Figure 1, center shows EELS data comparing different areas of the support structure with the data from deposited graphite and diamond nano-particles. The comparison shows a red-shift of the low-loss peaks of graphene with an increasing number of stacked graphene sheets with the biggest red shift occurring for graphite. It appears the redshift can be used to determine the number of overlaid Graphene sheets. As a comparison, the EELS data (FWHM ≤ 0.4eV) for graphite, diamond and amorphous C were added. Figure 1, right, shows the core loss part of the EELS spectra, consistent with the low-loss data.Similarly, diffraction data from the same sample and microscope can be used to differentiate the number of layers of Graphene as shown in Figure 2. The data were obtained from a beam with a 9mrad convergence angle and a spot size of 0.5nm diameter. For a large beam diameter of 60nm, the illumination can be adjusted (not shown here) to an almost parallel beam creating a diffraction pattern consistent with the diffraction patterns expected from a TEM (images not show).The surface of the sample was then imaged via SE at 1kV that allows identification of Au particles deposited on top of the graphene support structure and the result is shown in Figure 3, left. The acceleration voltage was then increased to 30kV and the corresponding SE and BF-STEM images are shown in the middle of Figure 3. The corresponding elemental map via EDX (Oxford Instruments) is shown in Figure 3, right.

No abstract

No abstract