Substrate surface roughness-dependent 3-D complex nanoarchitectures of gold particles from directed electrodeposition

The effects of substrate surface roughness on the directed electrodeposition of gold 3-D complex nanoarchitectures with hedgehog-shaped, cauliflower-shaped, or bunch-of-grapes-shaped surface features are revealed. The surface morphology of the synthesized particles was observed using a scanning electron microscope (SEM). Their chemical composition was confirmed using X-ray diffraction (XRD) patterns. The surfaces of ITO/glass substrate with different roughness were checked using atomic force microscopy (AFM) and contact angle measurements. Effects of variation of the deposition potential on the growth of Au nanocomplex structure have provided valuable information to clarify the substrate surface roughness-dependent 3-D nanocomplex synthesis. Pt/Au bimetallic particles with different surface features were produced under the same experimental conditions using mentioned different rough ITO/glass substrates. The growth follows a diffusion controlled mechanism. Electrochemical experimental results demonstrated that such hedgehog-shaped Au particles exhibit enhanced voltammetric responses. These findings offer insight into the electrosynthesis of complex micro/nano-structures. Interesting 3-D nanostructures can be realized by controlling the surface roughness of the substrate.