In this work, photocatalytic performance is divulged in the ternary CuO-Ag-ZnO nanowire synthesized via a two-step approach. The decoration of Ag and CuO nanostructures onto the surface of ZnO nanowires was simply carried out by using the plasma electrolytic oxidation method in a short time. The structure, size, morphology, and optical properties of as-prepared samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, and spectrophotometry measurements. The diameters of Ag nanoparticles and ZnO nanoflowers are in the range of 5–20 nm and 20–60 nm, respectively. Within the first 15 min, methyl orange was decolorized 96.3 and 82.8% in the CuO-Ag-ZnO and Ag-ZnO, respectively, and there is only about 46.7% of that decomposed in pure ZnO. The CuO-Ag-ZnO shows a higher rate constant k = 0.2007 min⁻¹ and a lower half-life time t = 6.1 min compared to Ag-ZnO and bare ZnO nanowires. The photo-reusability of the ternary nanostructures was estimated to be much outweighed compared to ZnO nanowires. Interestingly, the synergic incorporation between noble metal–semiconductor or semiconductor–semiconductor in the interfaces of Ag-CuO, Ag-ZnO, and CuO-ZnO expands the visible light absorption range and eliminates the photogenerated electron–hole recombination, resulting in a superior visible-light-driven photocatalyst.

The synthesis of silver pyrovanadate, Ag₄V₂O₇, nanoplates with exposed {0 0 1}-facets by a facile, additive-free hydrothermal method was described in this paper. The photocatalytic activity of rhodamine B over Ag₄V₂O₇ samples under solar light irradiation was also evaluated. By using an equimolar mixture of NH₄VO₃ and AgNO₃ with the presence of a suitable amount of ammonia, Ag₄V₂O₇ nanoplates were obtained readily and purely at temperatures from 100 to 140°C for 4 h. In particular, the c-axis orientation growth of Ag₄V₂O₇ nanoplates occurred and increased monotonously with temperatures in the range of over 100 up to 140°C. Further increase in hydrothermal temperature up to 220°C, the Ag₄V₂O₇ phase no longer existed and the β-AgVO₃ phase was formed instead. The photocatalytic activity of the optimized Ag₄V₂O₇ sample comprising {0 0 1}-facet-exposed nanoplates with the highest degree of orientation was significantly higher than that of the random-oriented sample. The effects of using ammonia as a complexing agent on the structure, microstructure, texture, exposed facet, and photocatalytic activity of Ag₄V₂O₇ samples were also investigated for the first time.

In this study, we developed a pioneering non-enzymatic electrochemical sensor utilizing a flexible porous graphene electrode modified with ZnO nanoparticles (ZnO/fPGE sensor) to assess hypoxanthine (HXA) content in pork at post-mortem time. The ZnO/fPGE sensor was synthesized via hydrothermal method and direct laser writing with a CO2 laser on a polyimide film at ambient conditions. Its characterization was analyzed by Raman, Fourier-transform infrared spectroscopy, field-emission scanning microscopy, energy-dispersive x-ray spectroscopy, and cyclic voltammetric techniques. Linear response, the limit of detection, and sensitivity to the HXA were enhanced with the values of the range from 1.5 to 150, 0.14 µM, and 6.6 µA μM−1 cm−2, respectively. Effective resistance to common physiological interferences (such as uric acid, ascorbic acid, dopamine, glucose, and xanthine) was indicated, and additionally, the determination of HXA concentration in real samples with good selectivity is attributed to the synergistic effects between ZnO nanoparticles and fPGE. Therefore, the ZnO/fPGE has provided a favorable electrical environment for developing high-performance electrochemical biosensors to determine hypoxanthine in pork meat.

We have designed an excellent visible-light-driven and high-performance photocatalyst with a Ag-Cu₂O-ZnO nanowire heterostructure in our work by combining the hydrothermal approach with plasma–liquid technology. The structural and morphological characteristics and optical properties of the samples were evaluated using X-ray diffraction, field-emission scanning electron microscopy, and spectrophotometry, respectively. The results show that the Ag nanoparticles are mainly positioned on the Cu₂O nanoclusters compared with the ZnO nanowire surface, forming broccoli-like Ag-Cu₂O nanoclusters during the Ar gas plasma treatment process in an aqueous solution. The diameter of the Ag/Cu₂O nanoclusters ranges from 150 to 180 nm. The Ag-Cu₂O-ZnO nanowires exhibited improved photocatalytic performance, decomposing approximately 98% methyl orange dye in 30 min. This is a consequence of the synergistic interactions between the p-n heterojunction formed at the Cu₂O-ZnO interfaces and the localized surface plasmon resonance (LSPR) effect of the Ag nanoparticles, which broaden the visible light absorption range and effectively separate the photogenerated charge carriers.

The electrical properties of individual ZnO nanorods were investigated. Chemical vapor deposition was used to grow arrays of ordered ZnO nanorods on silicon substrates. A 3D manipulation system was used to separate individual nanorods. Then, these were transferred to interdigital platinum electrodes and welded together by means of an ion beam. The ohmic nature of the contact between platinum and zinc oxide was confirmed by electrical measurements. The high quality of the material was confirmed by studying the cathodoluminescence spectrum of these nanorods. A possibility of the diffusion length estimation in nanorods with ohmic contacts from the electron beam induced current measurements is demonstrated. It is shown that in ZnO nanorods grown by chemical vapor deposition, the diffusion length can reach values up to 2 μm. This value is a few times higher than the data available in the literature that confirm the low defect content in such nanorods.