Application of LIBS technology to the rapid measure of heavy metal contamination in soils

Laser-induced breakdown spectroscopy(LIBS) has emerged in the past ten years as a promising technique for analysis and measure. The fundamental principle of LIBS for in situ qualitative and quantitative analysis is introduced. Current development of the instrument and its applications in rapid detection of heavy metal contamination elements, such as As, Cd, Cr, Hg, Pb and Zn in soils are reviewed in detail. The critical problems such as how to achieve quantitative measurement and improve the detection limit of LIBS are discussed

Developing high photocatalytic antibacterial Zn electrodeposited coatings through Schottky junction with Fe3+-doped alkalized g-C3N4 photocatalysts

Pure Zn coatings easily lose their protective performance after biofouling because they have no antibacterial effect under visible light. In this study, we fabricate a new antibacterial Zn composite coating using electrodeposition to couple Fe3+-doped alkalized g-C3N4 (AKCN-Fe) into an existing Zn coating and show that the AKCN-Fe enhances antibacterial property of the Zn coating under visible light. We attribute this enhancement to the high photocatalytic performance, high loading content, and good dispersion of AKCN-Fe. In addition, the photocatalytic antibacterial mechanism of the composite coating is supported by scavenger experiments and electron paramagnetic resonance (EPR) measurements, suggesting that superoxide (·O2−) and hydroxyl radical (·OH) play main and secondary roles, respectively

Perfect Combination of LBL with Sol–Gel Film to Enhance the Anticorrosion Performance on Al Alloy under Simulated and Accelerated Corrosive Environment

Given their outstanding versatile properties, multilayered anticorrosion coatings have drawn great interest from researchers in the academic and engineering fields. However, the application of multilayered coatings is restricted by some limitations such as low interlayer compatibilities, the harsh preparation process, etc. This work introduced a composite film fabricated on a 2A12 aluminum alloy surface, including an anodic oxide film, a sol–gel film, and a layer-by-layer (LBL) self-assembling film from bottom to top. The microstructure and elemental characterization indicated that the finish of the coating with the LBL film resulted in a closely connected multilayered coating with a smoother surface. The anticorrosion performance was systematically evaluated in the simulated corrosive medium and neutral salt spray environment. The integrated coating with the LBL film presented an excellent anticorrosion ability with system impedance over 108 Ω·cm2 and a self-corrosion current density two orders of magnitude lower than that of the other coatings. After the acceleration test in a salt spray environment, the multilayered coatings could still show a good protective performance with almost no cracks and no penetration of chloride ions. It is believed that the as-constructed multilayered coating with high corrosive properties and a fine surface state will have promising applications in the field of anticorrosion engineering