Synthesis and structure of carbon belts made of carbon nanofibers supported on carbon foams

Two-dimensional carbon belts (CBs) made of carbon nanofibers (CNFs) supported on a carbon foam (CFoam) substrate have been synthesized by a procedure involving carbonization of polyamic acid (PAA)/Ni(NO₃)₂ solution impregnated polyurethane foam in flowing H₂ at 700 °C and catalytic chemical vapor deposition (CCVD) using C₂H₄ as a carbon source and SO₂ as a promoter. The CBs, which are hundreds of micrometers in length, several micrometers in width and tens of nanometers in thickness, are made of CNFs with a low degree of graphitization that array with an orientation roughly parallel to the longitudinal axis of the CBs. The results show that the mass ratio of Ni to PAA, a H₂ atmosphere in carbonization and SO₂ in CCVD process are the three key factors governing the growth of the CBs.     

Synergistic effect of various elements in Fe41Co7Cr15Mo14C15B6Y2 amorphous alloy hollow ball on catalytic degradation of methylene blue

Metallic glasses have recently attracted great attention in terms of degrading dyes and other organic pollutants as an environmentally friendly material for was...     

Effect of hydrogen on pitting corrosion of 2205 duplex stainless steel under alternating dry/wet marine environment

Stainless steels play an extremely vital role in the field of marine engineering equipment. However, stainless steel products in service are still subject to corrosion from severe environments such as alternating dry/wet condition and damage caused by hydrogen introduced during heat treatment or cathodic protection. Under alternating dry/wet marine environment, the synergistic effect of hydrogen and corrosion can influence the corrosion resistance of stainless steels dramatically. In this work, the corrosion behavior and mechanism of 2205 duplex stainless steel under alternating dry/wet marine environment are investigated before and after hydrogen charging using electrochemical testing, component characterization and morphological observation. The results show that the open circuit potential, film resistance and breakdown potential all reduce and the passive current density increases after 12 h hydrogen charging. The ratio of Fe³⁺ and O²⁻/OH⁻ decreases. The components of the hydrogen charged passive film alter and the performance deteriorates. The number of surface pits increases after 12 h hydrogen charging and additional 10 d alternating dry/wet corrosion. The pitting potential drops much lower. Consequently, The synergistic effect of high concentrations of Cl⁻ in the thin liquid film and hydrogen accelerates the destruction of the passive film, further reducing the corrosion resistance of stainless steels.     

Electrocatalyst of RuO2 decorating TiO2 nanowire arrays for acidic oxygen evolution

Oxygen evolution reaction (OER) at the anode limits the efficiency of hydrogen production from water electrolysis substantially. A novel electrocatalyst of RuO₂ decorating TiO₂ nanowire arrays for OER was successfully prepared using a cyclic voltammetric method with electrodeposition of RuO₂ nanoparticles on the TiO₂ nanowire (TNW) arrays synthesized hydrothermally. Even though the electrodes with the composite electrocatalyst have a lower loading of RuO₂, they have higher electrocatalytic activity and stability for acidic oxygen evolution than the Ti/RuO₂ electrode prepared by conventional thermal decomposition method. The core-shell structure of the TNW@RuO₂ electrocatalyst not only increases the specific surface area of the electrodes, but also inhibits the adverse effect of the poor conductivity of TiO₂. This novel OER electrocatalyst can improve the efficiency and reduce the cost of hydrogen production from electrolytic water splitting.