A strategy for the preparation of super-hydrophilic molybdenum disulfide composites applied to remove uranium from wastewater.

Due to the radioactivity of uranium, the discharged nuclear wastewater not only causes certain damage to the ecology, but also causes certain harm to human life and health. Adsorption is considered to be one of the most effective ways to remove uranium. In this paper, a kind of MoS2 adsorbent was prepared by the solid phase synthesis method and functionalized with NiCo-LDH. The raw materials of MoS2 are cheap and easy to obtain, and the preparation conditions are simple, and large quantities can be obtained without limitations. MoS2 functionalized with NiCo-LDH provides more adsorption sites for the adsorbent and at the same time improves the hydrophilicity of the adsorbent, so that the active sites can fully combine with uranyl ions. The maximum adsorption capacity of the Langmuir isothermal adsorption model is 492.83 mg g-1. The selective adsorption capacity of uranium can reach 76.12% in the multi-ion coexistence system. By analyzing the adsorption mechanism with FT-IR and XRD, it is believed that on the one hand, UO22+ forms a covalent bond with Mo in MoS2 and coordinates with S on the surface of MoS2. On the other hand, UO22+ enters the NiCo-LDH layer for ion exchange with NO3- and coordinates with -OH on the surface of NiCo-LDH. The successful preparation of the MoS2/NiCo-LDH composite provides a certain application prospect for the uranium adsorption field.

Electrochemical migration behavior of moldy printed circuit boards in a 10 mT magnetic field.

In the electrochemical migration behavior (ECM) of printed circuit boards containing mold under a static magnetic field (SMF), the role of the field perpendicular to the electrodes is discussed; the B field inhibits the growth and metabolism of mold, while controlling electrochemical diffusion and nucleation. The field indirectly affects the function of mold as a transmission bridge between two electrodes. In this work, the water drop test was used to simulate the adhesion and growth of mold on the circuit board in a humid and hot environment; confocal laser scanning microscopy, scanning electron microscopy, energy dispersive spectroscopy, Raman spectra, and a scanning Kelvin probe were used to analyze the mechanism of static magnetic field and mold on the electrochemical migration.

Effect of static magnetic field on mold corrosion of printed circuit boards.

Mold has a strong impact on the corrosion behavior of metals, especially under environmental conditions conducive to mold growth. However, the magnetic fields generated by electronic devices have effects on the metal corrosion and mold growth. In this study, a 10 mT static magnetic field (SMF) perpendicular to the surface of samples was applied to study the corrosion of a copper-clad printed circuit board (PCB-Cu) by mold under the SMF. Based on the analysis of the corrosion morphology of the PCB-Cu after a test in the atmosphere and the composition of the corrosion products, the corrosion behavior of mold on the PCB-Cu in the presence or absence of the SMF was revealed. In the absence of a magnetic field, mold formed a spore-centered corrosion pit group on the surface of the PCB-Cu, which was macroscopically characterized by regional uniform corrosion. When a 10 mT SMF was applied, the magnetic field exhibited an inhibitory effect on the growth of mold, which was hindered, and the corrosion of the PCB-Cu surface slowed down.

Effect of iron ion diffusion on the corrosion behavior of carbon steels in soil environment.

The corrosion behavior of metal materials in soil environments has been intensively studied recently. Even so, the detailed corrosion mechanisms remain elusive, especially regarding the role of metal ions. In this study, we investigated the effect of ion diffusion on the corrosion processes of carbon steel via scanning electron microscopy (SEM), in situ laser Raman spectroscopy and scanning Kelvin probe (SKP). It was found that the Fe3+ diffusion was a key factor to the corrosion rate, as well as the formation of corrosion products. Typically, the corrosion products suppressed the diffusion of ions to the surface of carbon steels, and thus the cation diffusion coefficient played a significant role in formation processes of corrosion products, which furthermore affected the corrosion processes of the carbon steels.

Corrosion Behavior of Silver-Plated Circuit Boards in a Simulated Marine Environment with Industrial Pollution.

The electrochemical corrosion behavior of a silver-plated circuit board (PCB-ImAg) in a polluted marine atmosphere environment (Qingdao in China) is studied through a simulated experiment. The morphologies of PCB-ImAg show some micropores on the surface that act as the corrosion-active points in the tests. Cl- mainly induces microporous corrosion, whereas SO2 causes general corrosion. Notably, the silver color changes significantly under SO2 influence. EIS results show that the initial charge transfer resistance in the test containing SO2 and Cl- is 9.847 × 10³, while it is 3.701 × 104 in the test containing Cl- only, which demonstrates that corrosion accelerates in a mixed atmosphere. Polarization curves further show that corrosion potential is lower in mixed solutions (between -0.397 V SCE and -0.214 V SCE) than it in the solution containing Cl- only (-0.168 V SCE), indicating that corrosion tendency increases with increased HSO3- concentration.