Additive-Free Shape-Invariant Nano-to-Micron Size-Tuning of Cu<sub>2</sub>O Cubic Crystals by Square-Wave Voltammetry

2014-05-22T00:00:00Z (GMT) by Xuyun Guo Weiqiang Lv Xiao-Yuan Li
We demonstrate in this study the application of square-wave voltammetry (SWV), an electrochemical technique that has been commonly employed in electroanalysis but much less utilized in electrocrystallization, in the shape-invariant size-tuning of the electrodeposited cuprous oxide (Cu<sub>2</sub>O) crystalline cubic particles from ∼30 nm to 3 μm in aqueous solution under ambient conditions without using any organic surfactant and surface capping agent. We show systematically how each and every adjustable parameter in SWV technique affects the size-tuning of Cu<sub>2</sub>O nanocubes under shape invariance. A systematic comparison was made between SWV and several other EC techniques, including linear-sweep voltammetry (LSV), stair-case voltammetry (SCV), chronoamperometry (CA or simple <i>i</i> vs <i>t</i>), square-wave chronoamperometry (SWCA), and differential pulse voltammetry (DPV), for the shape-invariant electrodeposition of crystalline Cu<sub>2</sub>O nanocubes. The as-fabricated Cu<sub>2</sub>O nanocubes were employed as the size- and shape-controlled galvanic templates to fabricate Cu<sub>2</sub>O@Ag core–shell structures which display excellent performance in “single-particle” surface-enhanced Raman spectroscopy (sp-SERS).