Rahul Hajare

Sandip University, India

Abstract Title: Synthesis and Luminescence of NNanoporous Anodic Alumina Embedded with Vanadyl–Citrate Complexes

Biography: Dr Rahul Hajare completed his PhD at the age of 32 years from KLE Society’s College of Pharmacy, Bangalore, a constituent unit of KLE Academy of Higher Education and Research, Belagavi, and postdoctoral studies from ICMR. He is the professor of Sandip University. He has published more than 25 papers in reputed journals and has been serving as an editorial board member of repute.

Research Interest: Anodisation of aluminium enables the formation of self-organised, hexagonally ordered nanoporous anodic aluminium oxide (AAO). Owing to its highly tunable pore geometry, chemical stability, and large specific surface area, AAO has attracted considerable attention across numerous research fields, including nanofabrication, sensor development, superhydrophobic surface engineering, photonic crystal fabrication, organic photovoltaics, and biomaterials engineering. Highly ordered AAO is typically produced via anodisation in three main electrolytes: sulphuric, oxalic, and phosphoric acid. In many applications, the as-formed nanoporous oxide undergoes post-fabrication functionalisation to introduce additional properties. Common ex-situ approaches include pore impregnation with functional molecules, electrophoretic deposition of polymer nanoparticles, and magnetic-field-assisted nanoparticle deposition. Thorat et al. also reported post-fabrication in-situ filling of AAO with silver nanoparticles. However, these methods are applied to pre-formed AAO structures and primarily enable functionalisation of the inner pore surfaces. In contrast, the approach presented here involves real-time in situ functionalisation during oxide growth. During anodisation, electrolyte anions migrate toward the anode and interact with the growing oxide layer. These anions are adsorbed at the oxide surface and become progressively incorporated into the expanding anodic film. Consequently, electrolyte-derived species are embedded throughout the oxide matrix, as confirmed by high-resolution elemental mapping studies (e.g., Le Coz et al.). Extensive photoluminescence (PL) studies demonstrate that AAO exhibits characteristic emission bands originating from both incorporated electrolyte anions and oxygen vacancy-related F-centres. Time-resolved fluorescence measurements allow differentiation between these contributions: F-centre emission typically exhibits short decay times (<7 ns), whereas anion-related luminescence shows significantly longer decay lifetimes (up to 46 ns), as reported by Li et al.