Influence of Temperature Parameters on Morphological Characteristics of Plasma Deposited Zinc Oxide Nanoparticles

Zinc oxide nanoparticles were obtained by plasma-enhanced chemical vapor deposition (PECVD) under optical emission spectrometry control from elemental high-purity zinc in a zinc–oxygen–hydrogen plasma-forming gas mixture with varying deposition parameters: a zinc source temperature, and a reactor temperature in a deposition zone. The size and morphological parameters of the zinc oxide nanopowders, structural properties, and homogeneity were studied. The study was carried out with use of methods such as scanning electron microscopy, X-ray structural analysis, and Raman spectroscopy, as well as statistical methods for processing and analyzing experimental data. It was established that to obtain zinc oxide nanoparticles with a given size and morphological characteristics using PECVD, it is necessary (1) to increase the zinc source temperature to synthesize more elongated structures in one direction (and vice versa), and (2) to decrease the reactor temperature in the deposition zone to reduce the transverse size of the deposited structures (and vice versa), taking into account that at relatively low temperatures instead of powder structures, films can form.

Recent advances in ZnO-based photosensitizers: Synthesis, modification, and applications in photodynamic cancer therapy

Zinc oxide nanoparticles (ZnO NPs) are important semiconductor materials with interesting photo-responsive properties. During the past, ZnO-based NPs have received considerable attention for photodynamic therapy (PDT) due to their biocompatibility and excellent potential of generating tumor-killing reactive oxygen species (ROS) through gentle photodynamic activation. This article provides a comprehensive review of the recent developments and improvements in optical properties of ZnO NPs as photosensitizers for PDT. The optical properties of ZnO-based photosensitizers are significantly dependent on their charge separation, absorption potential, band gap engineering, and surface area, which can be adjusted/tuned by doping, compositing, and morphology control. Here, we first summarize the recent progress in the charge separation capability, absorption potential, band gap engineering, and surface area of nanosized ZnO-based photosensitizers. Then, morphology control that is closely related to their synthesis method is discussed. Following on, the state-of-art for the ZnO-based NPs in the treatment of hypoxic tumors is comprehensively reviewed. Finally, we provide some outlooks on common targeted therapy methods for more effective tumor killing, including the attachment of small molecules, antibodies, ligands molecules, and receptors to NPs which further improve their selective distribution and targeting, hence improving the therapeutic effectiveness. The current review may provide useful guidance for the researchers who are interested in this promising dynamic cancer treatment technology.

Designing novel morphologies of l-cysteine surface capped 2D covellite (CuS) nanoplates to study the effect of CuS morphologies on dye degradation rate under visible light

Novel CuS@l-Cys NPs are designed by a hydrothermal route. The effects of synthetic parameters on the morphologies of CuS@l-Cys NPs were investigated. CuS@l-Cys NPs exhibit an enhanced dye degradation rate under visible light.