Polycrystal CuO Curved Nanowires with Photocatalytic Antibacterial for Highly Sensitive Photoelectrochemical Detection of Ultralow-Concentration Ethanol in Solution

The polycrystal CuO curved nanowires were synthesized on Cu mesh by a facile alkalization method. The visible light-driven CuO curved nanowires were observed to have highly sensitivity for non-enzymatic ethanol sensing in solution and fast antibacterial property under flashlight irradiation. Compared to the single-crystal CuO nanowires, the polycrystal CuO nanowires were investigated based on the analysis of the morphology, nanostructure, theoretical modeling, and photoelectrochemical performance. As a result, the highest photocurrent densities were obtained by polycrystal CuO curved nanowires, as the facet heterojunction in curved nanowires played a key role, which existed in the interface between facets CuO (111) and CuO (110) resulting in the effectively separation of photoelectron-holes, thereby increasing the charge carrier density. Herein, the CuO curved nanowires were assembled as a photoelectrochemical sensor to detect the low concentration ethanol ranging from 10 to 100 nM, and then showed a high sensitivity. The fast antibacterial performance of CuO curved nanowires was found to completely kill 107 CFU/mL E.coli under flashlight irradiation in 20 minutes. The proposed CuO curved nanowires electrode with self-cleaning performance can be ideal for monitoring the low concentration ethanol in real-time at room temperature as photoelectrodes.

The Synergetic Effect Induced High Electrochemical Performance of CuO/Cu2O/Cu Nanocomposites as Lithium-Ion Battery Anodes

Due to the high theoretical capability, copper-based oxides were widely investigated. A facile water bath method was used to synthesis CuO nanowires and CuO/Cu2O/Cu nanocomposites. Owing to the synergetic effect, the CuO/Cu2O/Cu nanocomposites exhibit superior electrochemical performance compared to the CuO nanowires. The initial discharge and charge capacities are 2,660.4 mAh/g and 2,107.8 mAh/g, and the reversible capacity is 1,265.7 mAh/g after 200 cycles at 200 mA/g. Moreover, the reversible capacity is 1,180 mAh/g at 800 mA/g and 1,750 mAh/g when back to 100 mA/g, indicating the excellent rate capability. The CuO/Cu2O/Cu nanocomposites also exhibit relatively high electric conductivity and lithium-ion diffusion coefficient, especially after cycling. For the energy storage mechanism, the capacitive controlled mechanism is predominance at the high scan rates, which is consistent with the excellent rate capability. The outstanding electrochemical performance of the CuO/Cu2O/Cu nanocomposites indicates the potential application of copper-based oxides nanomaterials in future lithium-ion batteries.