Vertically cross-linking silver nanoplate arrays with controllable density based on seed-assisted electrochemical growth and their structurally enhanced SERS activity

A facile seed-assisted electrochemical deposition (ECD) route has been presented to fabricate silver nanoplate arrays at room temperature. The nanoplates are hundreds of nanometres to several micrometres in dimension and tens of nanometres in thickness. All the nanoplates are standing vertically on the indium-tin oxide substrate and cross-linking each other. Importantly, the number density of silver nanoplates in the array can be controlled by the amount of seeds pre-coated on the substrate. Further experiments have demonstrated that electric current density during ECD plays a crucial role in the final morphology of the products. A simple and flexible way is presented to study time-dependent morphological evolution only in one step, based on substrate-moved electrochemical deposition, which has revealed that each nanoplate grows up from individual Ag seeds on the substrate. The formation of nanoplates is attributed to the seed-assisted preferential nucleation and quasi-equilibrium oriented growth. Further studies indicate that such Ag nanostructured arrays can serve as highly active surface-enhanced Raman scattering (SERS) substrates and have very homogeneous SERS activity in whole sample.