Zinc oxide (ZnO) has been widely used as a photocatalyst for solar energy conversion and treatment of organic pollutants because of its low toxicity and high photocatalytic efficiency. However, the applicability of ZnO in visible light is limited because of the wide band gap of the material, which results in low efficiency during solar photoconversion. In this paper, we report the facile one-pot, morphology-controlled, and large-scale synthesis of carbon-doped ZnO through urea-assisted thermal decomposition of zinc acetate. Nanorods and nanospheres of carbon-doped ZnO were successfully prepared by using this one-step method with various weight percent of urea. The photocatalytic activities of nanocrystals obtained with different morphologies and carbon contents were evaluated through degradation of methylene blue with visible light irradiation. Results showed that incorporation of carbon decreases the energy band gap of ZnO, improves the separation efficiency of its electron-hole pairs, and significantly enhances the visible light photocatalytic activity.

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Electroplated hard chrome coating is widely used as a wear resistant coating to prolong the life of mechanical components. However, the electroplating process generates hexavalent chromium ion which is known carcinogen. Hence, there is a major effort throughout the electroplating industry to replace hard chrome coating. Composite coating has been identified as suitable materials for replacement of hard chrome coating, while deposition coating prepared using traditional co-deposition techniques have relatively low particles content, but the content of particles incorporated into a coating may fundamentally affect its properties. In the present work, Ni-W/diamond composite coatings were prepared by sediment co-electrodeposition from Ni-W plating bath, containing suspended diamond particles. This study indicates that higher diamond contents could be successfully co-deposited and uniformly distributed in the Ni-W alloy matrix. The maximum hardness of Ni-W/diamond composite coatings is found to be 2249 ± 23 Hv due to the highest diamond content of 64 wt.%. The hardness could be further enhanced up to 2647 ± 25 Hv with heat treatment at 873 K for 1 h in Ar gas, which is comparable to hard chrome coatings. Moreover, the addition of diamond particles could significantly enhance the wear resistance of the coatings.

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3D printing has attracted a lot of attention over the past three decades. In particular the Fuse Filament Fabrication (FFF) technique, general materials require low shrinkage during cooling and viscous behavior during extrusion through a nozzle. Semi-crystalline thermoplastics and their composites are of the relevance of new materials for 3D printing. However, the crystalline structures, for instance, may have a favorable impact on their printability. In this study, polypropylene/organoclay nanocomposites were prepared by melt extrusion using a twin-screw extruder. The effects of organoclay on the thermal, rheological and morphological properties were studied to evaluate the possibility of using the polypropylene/organoclay nanocomposites as the FFF 3D printing feedstock. Dioctadecyl dimethyl ammonium chloride (D18) was successfully used to modify the clay surfaces, providing a good dispersity and wettability of organoclay in the PP matrix.