Fto coated glass substrates

Prior to the coating, the FTO coated glass substrates (resistivity: 14Ω/sq⁻¹, Sigma Aldrich) were cleaned under ultrasonication with soap solution, DI water, isopropyl alcohol and finally, dried under nitrogen blow. The VO₂(M)/C counter electrode was prepared using a uniform mixture with 200 µl of DI water and few drops of Triton X. The paste was coated over the conducting side of the FTO glass substrate using doctor blade technique. The coated FTO were annealed at 200 °C for 30 min to remove the binder and then used as a counter electrode. Conventional Pt counter electrode was prepared with 10 mM H₂PtCl₆ in isopropanol solution on FTO substrate using the same doctor blade technique followed by thermal decomposition at 450 °C under air atmosphere.