Photochemical synthesis of ZnO/Ag heterogeneous nanostructure on chemically patterned ferroelectric crystals for high performance SERS detection

Highlights: • Synthesis of heterogeneous nanostructures by ferroelectric template is presented. • Shape of grown ZnO nanomaterials can be controlled by adjusting the synthesis time. • The effects of ZnO nanostructures on the morphology of Ag nanomaterials are studied. • The SERS substrate has superior performance, such as LOD<10^–8 M, EF = 6.99 × 10⁸. • ZnO/Ag production by ferroelectric templates assists the progress of green process. -- Abstract: An attractive strategy for effective Raman signal enhancement is to employ the synergistic action of electromagnetic and chemical mechanisms by using semiconductor/noble-metal nanostructures in the SERS substrates. This work presents the utilization of ferroelectric templates to synthesize the ZnO/Ag heterogeneous nanostructures photochemically for the SERS application. Under UVC illumination, the ferroelectric templates with permanent electrostatic field provide the photoelectrons required for silver photoreduction. Various shapes of ZnO nanostructures are grown on the ferroelectric templates by controlling the growth time. The influences of ZnO nanostructures on the size, density, and morphology of photoreduced silver nanomaterials are studied by various analytical techniques. The produced SERS substrate with the optimal ZnO/Ag nanostructures possesses the superior SERS performance, such as the limit of detection < 10⁻⁸ M, the enhancement factor 6.99 × 10⁸, the uniformity 9.5% ± 1.0%, and 16-fold Raman intensity enhancement. This study demonstrates a promising green technique to produce semiconductor/noble-metal nanostructures using ferroelectric templates.