Influence of the filling ratio of vial in chemical surface and physicochemical properties of ZnO nanoparticles obtained by planetary ball milling process

Abstract

The production of nanoparticles (Np) is an important sector in current technological development. Processes such as high‐energy grinding are among the most promising because of their high efficiency and low energy cost. In this sense, the filling ratio of vial (FRV) is one of the most interesting and poorly studied process variables that can optimize the production of Np on a large scale. In the present work, dry ZnO Np are produced, with different FRV values (40%, 38%, 23%, and 10%), as well as wet samples. The results show that the variation of the FRV allows to generate an energetic increase of the grinding, modifying the morphology, the particle size, and the surface area of the ZnO powders, without generating structural or chemical changes. The X‐ray diffraction (XRD) results show the presence of the zincite phase (hexagonal) with a variation in crystallinity depending on the FRV, which is due to the deformation of the Np during the process. The XPS results showed a slight chemical shift (variation in binding energy) as a function of grinding because of the activation shown by deformation. UV–VIS analyses showed a marked increase in the magnitude of absorbed intensity for all analyzed samples compared with the commercial powder. These results confirm that FRV is a sensitive parameter in the process of obtaining ZnO Np by the planetary mill technique, which allows efficient control of its characteristics for a given application.

Influence of pH on Room-Temperature Synthesis of Zinc Oxide Nanoparticles for Flexible Gas Sensor Applications

“…The characteristic UV-Vis absorbance peak of ZnO NPs highlighted discernible differences within the 340 nm to 380 nm range, contingent upon their respective preparation conditions, as seen in Figure 7A. In contrast, hyd.C induced an absorbance peak at 375 nm, attributed to the transition occurring within the oxygen functional groups [90], and indicating NP formation [91,92]. Notably, the UV-Vis absorption spectra of RT.pH(x) and RT.pH(x).C exhibited a close resemblance, irrespective of the calcination process, and showcased an absorbance profile similar to hyd-C. As measured by the BET technique, ZnO NPs' specific surface area fell in the 4-126 m 2 g −1 range [87][88][89].…”