Abstract
<jats:p>Homogeneous growth within ordered mesoporous templates remains difficult because strong nanoscale confinement is both poorly understood and challenging to characterise. Here, we report sub-4 nm Bi2Te3 nanostructures grown by electrodeposition within mesoporous silica thin films. Vertically aligned nanowire arrays with diameters of 3.7 nm and lengths of ~230 nm were grown in P6mm templates, while interconnected three-dimensional nanowire networks were formed in Fmmm templates with diameters of approximately 8 nm. Electron microscopy confirms homogeneous filling of both structures. Operando grazing-incidence small-angle X-ray scattering (GISAXS) shows that homogeneous growth proceeds through the transient coexistence of electrolyte-filled and Bi2Te3-filled mesophases. This produces characteristic Bragg peak splitting, which provides a direct structural signature of homogeneous growth within the buried pore network. The growth mechanism is independent of pore geometry and size. These findings establish a mechanistic framework for confined electrodeposition across pore architectures.</jats:p>