Polymer-mediated surface engineering enables directional growth of RuO 2 nanorods on electrospun V 2 O 5 nanofibers

Controlling the morphology of metal oxide nanostructures through simple and scalable synthetic strategies remains challenging because crystal growth is strongly governed by interfacial surface chemistry. Herein, we present a polymer-mediated strategy for directing the growth of RuO 2 nanorods on electrospun V 2 O 5 nanofibers by tuning the polyvinylpyrrolidone (PVP)/polyacrylonitrile (PAN) ratio in the precursor solution. PAN incorporation preserves the one-dimensional V 2 O 5 framework while progressively promoting the formation of vertically aligned RuO 2 nanorods. Structural and spectroscopic analyses reveal that PAN-induced thermal evolution modifies the surface chemistry of V 2 O 5 by increasing pyridinic nitrogen functionalities and oxygen-deficient surface sites. These surface characteristics are proposed to facilitate preferential Ru precursor nucleation, leading to anisotropic crystal growth without altering the crystal structures of either V 2 O 5 or RuO 2 . The optimized composition containing 50 wt % PAN exhibits the most homogeneous and vertically aligned RuO 2 nanorod arrays.