Search

The process of preparing surface composite by molten salt co-deposition is the result of the mass transfer of active particles in molten salt, electrochemical reduction, and solid diffusion. In this study, we prepared Cr–Ni alloy/low-carbon steel surface composites in NaCl, KCl, NaF, Cr2O3, and NiO melt salt system successfully, and analyzed the entire diffusion dynamics process, aiming to find out the limiting links and provide ideas for further improving the preparation efficiency. The results show that chromium and nickel ions are simultaneously reduced on the cathode surface through two and one steps, respectively. And an alloy layer with Fe content of 64.52 wt%, Ni content of 28.96 wt%, and Cr content of 6.52 wt% is formed on the surface of low-carbon steel substrate. The average diffusion coefficients of chromium and nickel atoms in the surface composites are 1.16 × 10−14 and 1.44 × 10−14 m2·s−1. The mass transfer process in molten salt is the limiting link in the whole preparation process.

An energy-efficient and environmentally friendly nitrogen fixation process is urgently needed to solve problems of high energy consumption and high emissions in the traditional ammonia industry. In this work, a Z-scheme porous g-C3N4/ZnFe2O4 photocatalyst was synthesized, characterized and employed for N2 photofixation. Temperature programmed desorption characterization confirmed that the adsorption capacity of nitrogen was improved for the porous structure. From N2 photofixation evaluation experiments, the highest ammonia production efficiency can reach 147.33 μmol/L within 120 min. Photocatalytic performance is greatly improved because of the increasing of specific surface areas, enhancement of N2 adsorption ability and synergistic effect of Z-scheme photocatalytic system. In the ammonia production process of the research, visible light is used as energy; N2 and H2O are used as raw materials, which possesses a good application potential due to the advantages of being energy-efficient, environmentally friendly and pollution-free. [ABSTRACT FROM AUTHOR]

Abstract: Silicon-containing polyimide/BaTiO3 nanocomposite films were prepared by the direct mixing of silicon-containing polyamic acid and BaTiO3 nanoparticles under ultrasonic wave irradiation, followed with thermal imidization. Structure and thermal properties were measured with FTIR, XPS, SEM, DSC and TGA. The results showed that the compatibility of BaTiO3 and a polyimide might be improved by the introduction of dimethylsilylene groups into the backbone of a polyimide; and BaTiO3 nanoparticles in the nanocomposites tended to form clusters. The clusters coalesced into a more uniform structure at a higher BaTiO3 filling than at a lower one.The interfacial interaction between BaTiO3 and the silicon-containing polyimide resulted in the increase of the glass transition and the thermal decomposition temperature. It was found that the nanocomposites exhibited lower infrared emissivity value than the pure polyimide and the magnitude of infrared emissivity value was related to the content of BaTiO3 in the nanocomposites. [Copyright &y& Elsevier]

For digging out eco-friendly and well-performed energy harvesters, piezoelectric nanogenerators are preferred owing to their effortless assembly. Corona-poling promotes output performance of either aligned or porous PVDF electrospun films and higher piezoelectric output was achieved by corona-poled porous PVDF electrospun films due to more poled electret dipoles in pores. Increasing the duration of electrospinning rendered more electret dipoles in PVDF porous electrospun films, resulting in higher piezoelectric output. Moreover, corona-poled PVDF/Y-ZnO porous electrospun films performed better than corona-poled PVDF/ZnO porous electrospun films because of the larger polar crystal face of Y-ZnO. Flexible piezoelectric polymer PVDF and high-piezoelectric Y-ZnO complement each other in electrospun films. With 15 wt% of Y-ZnO, corona-poled PVDF/Y-ZnO porous electrospun films generated maximum power density of 3.6 μW/cm 2 , which is 18 times that of PVDF/BiCl 3 electrospun films.