Structural, Optical, and Electrochemical Characteristics of Sb ₂ O ₄ Nanorods Synthesized by Chemical Vapor Deposition Under O ₂ /Ar Atmospheres

A controlled chemical vapor deposition (CVD) route was adopted to synthesize Sb 2 O 4 nanorods with growth durations between 25 and 100 min under optimized O 2 /Ar atmospheres. Extended deposition promoted the formation of a pure orthorhombic Sb 2 O 4 phase with improved crystallinity, accompanied by a morphological transition from irregular particles to highly oriented nanorods. The refined structure induced bandgap narrowing from 4.17 to 4.11 eV, enhancing visible‐light absorption and charge transport. Electrochemical evaluation revealed that optimized Sb 2 O 4 nanorods (S4) achieved a specific capacitance of 484.6 Fg −1 and an energy density of 242.3 Whkg −1 , with excellent cyclic stability of 95% retention. Photocatalytic studies using Acid Orange dye under UV irradiation demonstrated a degradation efficiency of 94.03% and a shortest half‐life of 23.22 min, attributed to enlarged surface area and effective charge carrier separation. These combined improvements in crystallinity, optical response, and electrochemical activity establish CVD‐grown Sb 2 O 4 nanorods as a multifunctional material platform for advanced supercapacitor and photocatalytic applications.