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A series of nitrogen and oxygen enriched porous carbons are prepared from poly-N-phenylethanolamine (PNPEA) and polyaniline (PANI) conducting polymers through pyrolysis, chemical activation, and oxidation processes. Ar or N 2 -adsorption, FT-IR, and X-ray photoelectron spectroscopy are used to characterize the surface areas, pore volumes, surface chemical compositions, and oxygen and nitrogen content. Mikhail and Brunauer micropore analytical method (MP method) is successfully used to analyze the micropore size distribution of the samples. The electrochemical behaviour of the samples is studied in two-and three-electrode cells. The contribution of pseudocapacitance is confirmed by cyclic voltammetry and galvanostatic tests performed in acidic (H 2 SO 4 ) and basic (KOH) media. The potential drop and the equivalent series resistance value certify that the samples with wide micropore size distribution possess low interface resistances. A sample with a BET surface area of 760 m 2 g -1 , nitrogen content of 3.02 at.%, oxygen content of 16.65 at.%, and a wide micropore size distribution, presents the best performance, reaching a value of 370 F g -1 at 0.5 A g -1 and 248 F g -1 at 30 A g -1 , and maintaining capacitance retention ration of 96% at 1 A g -1 (over 1000 cycles) and 92% at 30 A g -1 (over 10000 cycles), respectively. The results obtained for all the samples agree with correlation among capacitance, functional group, and porosity, which indicates that an appropriate selection of the surface chemistry, a reasonable pore size distribution, and a moderate BET surface area, may be promising to achieve high-rate-performance supercapacitors.

Despite many decades of research of diodes, which are fundamental components of electronic and photoelectronic devices with p-n or Schottky junctions using bulk or 2D materials, stereotyped architectures and complex technological processing (doping and multiple material operations) have limited future development. Here, a novel rectification device, an orientation-induced diode, assembled using only few-layered black phosphorus (BP) is investigated. The key to its realization is to utilize the remarkable anisotropy of BP in low dimensions and change the charge-transport conditions abruptly along the different crystal orientations. Rectification ratios of 6.8, 22, and 115 can be achieved in cruciform BP, cross-stacked BP junctions, and BP junctions stacked with vertical orientations, respectively. The underlying physical processes and mechanisms can be explained using "orientation barrier" band theory. The theoretical results are experimentally confirmed using localized scanning photocurrent imaging. These orientation-induced optoelectronic devices open possibilities for 2D anisotropic materials with a new degree of freedom to improve modulation in diodes.

Pt was deposited onto tungsten carbide powders using atomic layer deposition to produce core-shell catalysts for the hydrogen evolution reaction (HER). The Pt loading on these catalysts was reduced nearly ten-fold compared to a bulk Pt catalyst while equivalent HER activities were observed.

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