Enhanced Electrochemical Water Splitting Activity Using Annealed TiO 2 Nanoparticles As Photoanodes

We present the photoelectrochemical characteristics of TiO 2 nanoparticle-based photoanodes. TiO 2 nanoparticles (P25) were deposited on fluorine-doped tin oxide (FTO) substrate by spin-coating and thermally annealed in a vacuum for enhancing the active photocatalyst. At a potential of 0.4 V (versus a reversible hydrogen electrode), the annealed TiO 2 nanoparticle-based photoanode in vacuum shows a photocurrent density of 0.27 mA/cm 2 and photoconversion efficiency of ( η = 0.22%), which are higher than those an of annealed TiO 2 nanoparticle-based electrode in air. The improved photoelectrochemical properties are attributed to high oxygen vacancy (OV) density with more active sides while TiO 2 nanoparticles are annealed in a vacuum (~1.33 × 10 −2 kPa) with low oxide concentration conditions. From this finding, we propose that thermal annealing can serve as an approach for fabricating the photoanodes of TiO 2 -based material consisting of a more active photocatalyst.