Search

Recent studies on intermetallic glasses challenged the conventional cognition that the glass formability would be deteriorated by the presence of intermetallics. To reveal the vitrification mechanism of intermetallics, three binary metallic alloys with multiple intermetallics and wide glass forming region are focused. The thermodynamics and dynamics of the intermetallics are studied by combining experiments and simulations, revealing that the glass forming systems can be featured by low melting entropy, low diffusion coefficient, and low formation enthalpy. Close inspection emphasizes the critical influence of the melting entropy in glass formation of intermetallics, and intermetallics with low melting entropy are of enhanced glass formability. In addition, for the glass forming intermetallics, the melting entropy shows close connection to the dynamics such as diffusion coefficients or viscosity of the liquids at melting temperature, with which a basic reference to design metallic glasses is substantiated.

A novel carbon quantum dots decorated C-doped α-Bi2O3 photocatalyst (CBO/CQDs) was synthesized by solvothermal method. The synergistic effect of adsorption and photocatalysis highly improved contaminants removal efficiencies. The ceftriaxone sodium degradation rate constant (k) of CBO/CQDs was 11.4 and 3.2 times that of pure α-Bi2O3 and C-doped α-Bi2O3, respectively. The interstitial carbon doping generated localized states above the valence band, which enhanced the utilization of visible light and facilitated the separation of photogenerated electrons and holes; the loading of CQDs improved the charge carrier separation and extended the visible light response; the reduced particle size of CBO/CQDs accelerated the migration of photogenerated carriers. The •O2− and h+ were identified as the dominant reactive species in ceftriaxone sodium degradation, and the key role of •O2− was further investigated by NBT transformation experiments. The Fukui index was applied to ascertain the molecular bonds of ceftriaxone sodium susceptible to radical attack, and intermediates analysis was conducted to explore the possible degradation pathways. The toxicity evaluation revealed that some degradation intermediates possessed high toxicity, thus the contaminants require sufficient mineralization to ensure safe discharge. The present study makes new insights into synchronous carbon dopping and CQDs decoration on modification of α-Bi2O3, which provides references for future studies.