Influence of Bio-Based Surfactants on TiO2 Thin Films as Photoanodes for Electro-Photocatalysis

Abstract

Photocatalytic water splitting into hydrogen is considered as one of the key solutions to the current demand for eco-responsible energy. To improve the efficiency and sustainability of this process, the development of a TiO2-based photoanode by adding bio-sourced surfactants to the sol–gel preparation method has been considered. Three different polymeric biosurfactants (GB, GC, and BIO) have been tested, giving rise to three different materials being structurally and morphologically characterized by XRD, Rietveld refinement, BET, SEM, AFM, and XPS, which was completed by light absorption, photocatalytic (Pilkington test), electronic (EIS and C-AFM), and photoelectrochemical (cyclic voltammetry) measurements. Correlations between the structure/morphology of materials and their functional properties have been established. One specific surfactant has been proven as the most suitable to lead to materials with optimized photoelectrochemical performance in direct relation with their photocatalytic properties essentially controlled by their specific surface area.