Fabrication Of Copper-supported Nanostructured Cuprous Oxides For Supercapacitors And Biosensors

Nanostructured Cu oxides/hydroxides are promising electrode materials for supercapacitors due to their high theoretical capacitances, low cost and friendliness to environment. However, it is still challengeable to develop commercially viable Cu oxides/hydroxides with superior capacitive performance. Here, cuprous oxide nanoneedle arrays in-situ growing on Cu foam were developed via a two-step electrochemical method. The nanoneedles have single crystalline features and mesoporous surface. The electrode exhibits high capacitance of 862.4 F g-1 and excellent cycling stability (20 000 cycles). Furthermore, we have successfully constructed an asymmetric supercapacitor by using Cu foam-supported Cu2O nanoneedle arrays as positive electrode and active carbon as negative electrode. The assembled supercapacitor can achieve an energy density of 35.6 W h kg-1 at 0.9 kW kg-1, and an energy density of 6.7 W h kg-1 at 6.3 kW kg-1. Besides, the asymmetric supercapacitor exhibits excellent stability with capacitance retention of 92% after 10 000 cycles. After being charged for 1 min, our in-series supercapacitors can drive LED arrays, and charge a mobile phone. These fascinating performances reasonably indicate their potential in commercial applications for energy storage.Highly sensitive and efficient biosensors play a crucial role in clinical, environmental, industrial and agricultural applications, and tremendous efforts have been dedicated to advanced electrode materials with superior electrochemical activities and low cost. In this paper, when the fabricated Cu foam-supported Cu2O nanoneedle arrays electrode was used as a potential biosensor for non-enzyme glucose detection, it exhibited multi-stage linear detection ranges with ultrahigh sensitivities (maximum of 97.9 mA mM-1 cm-2) and an ultralow detection limit of 5 nM. Furthermore, the electrode presents outstanding selectivity and stability towards glucose detection. The distinguished performances endow this novel electrode with powerful reliability for analyzing human serum samples, indicating its potential for practical application. These unprecedent sensing characteristics could be ascribed to the synergistic action of superior electrochemical catalytic activity of Cu2O nanothorn arrays with dramatically enhanced surface area and intimate contact between the active material (Cu2O) and current collector (Cu foam), concurrently supplying good conductivity for electrons/ions transport during glucose biosensing.Increasing demand for next-generation portable electronics with roll-up and wearable characteristics has inspired intensive efforts to explore high-performance energy storage devices that are flexible, lightweight, and environmentally friendly. Here, we report a facile, low-cost and high-throughput synthesis of hierarchical structure which consists of cuprous oxide (Cu2O) microsphere-nanosheets on the surface of flexible Cu foil via facile electrochemistry. The influence of anodization parameters on surface roughness of Cu foil has been investigated, and the optimum anodization procedure was determined to be 50 V for 4 cycles. The Cu2O nanosheets exhibit excellent capacitance properties, such as up to 390.9 mF cm-2 at 2 mA cm-2 in areal capacitance and high flexibility, as observed by cyclic voltammetry measurement under various deformation (bending and folding) situations. Furthermore, the Cu2O nanosheets electrode presents superior long-term cycling stability over 100 000 cycles, with the capacitance retention of 80.4%.