Abstract
Three dimensional material systems of heterostructured ZnSe nanoparticles/Si wires arrays and Cu-oxide micro flower clusters on Cu foil with unique properties and corresponding applications have been investigated. P-type micron size silicon wire (SiW) arrays coated with ZnSe nanoparticles (NPs) exhibiting enhanced photodetection and photocatalytic performances were synthesized. The SiWs were grown by combining catalytic etching with nanosphere lithography methods. ZnSe NPs were coated on SiWs with a chemical bath deposition (CBD) method. The high photodetection performance of three-dimensional (3D) heterostructured ZnSe NPs/SiWs arrays with immediate decay (> 99.85%), on/off ratio (> 7 × 10 2) and photoresponse speed (< 0.4 s) were recorded under a small applied voltage (80 μV). The immediate decay and on/off ratio increase with decreasing applied voltage and the photocurrent variations of ZnSe NPs/SiWs were larger than 0.3 μA at 1 V. The enhanced UV photocurrent response is attributed to large surface-to-volume ratio and presence of the fast conductive pathway of ZnSe NPs/SiWs shell/core heterostructures. ZnSe NPs/SiWs also showed superb photocatalytic properties with methylene blue (MB) and acid fuchsin (AF) as reagents. The photodegradation data exhibited high activities of 88% and 83% after 120 and 110 min, respectively. The CBD of ZnSe NPs on SiWs provides a facile route for the fabrication of well aligned 3D heterostructured ZnSe NPs/SiWs arrays with a high on/off ratio photocurrent and photocatalytic activity. Cu(OH)2, CuO, and Cu2O micro flower clusters on Cu foil were synthesized by a facile chemical method. Three dimensional self-assembled micro flower cluster structures were formed at a low temperature (5 °C) without utilizing surfactant and template. The growth of robust Cu(OH)2 micro flower clusters/Cu foil strongly depends on the growth temperature and alkaline concentration. The robust Cu(OH)2 micro flower clusters was transformed to CuO or Cu2O at a controlled temperature on Cu substrate. The morphologies, structures, and thermal properties of Cu(OH)2, CuO and Cu2O micro flower clusters were examined by scanning electron microscopy, in-situ X-ray energy dispersive spectrometer, transmission electron microscopy, and thermo-gravimetric analyzer/differential thermal analyzer. Cyclic voltammetry is demonstrated to be a good electrochemical technique for the non-enzymatic detection of glucose. The CuO micro flower clusters/Cu foil electrode presents a fast amperometric response time (1.5 s), high sensitivity (3.3 mA/mM) and appropriate linear range (0.25 μM to 1.0 mM) for glucose detection.