Bimetallic systems of ZnO/Al/Ag applied on cell PEC and photocatalytic system

Abstract

The synthesis of bimetallic systems of ZnO/Al/Ag deposited on glass substrate was carried out by the combination of sol-gel and spin-coating methods, used as an easy and simple alternative to prepare this kind of films, in comparison with other reported methods. Structural parameters and morphology on the surface of bimetallic films were determined by analytic techniques. While band gap value was calculated by Tau graph through UV–Vis analysis. Photocatalytic and photoelectrochemical tests were also carried out to analyze the behavior of the films and the effect provided by the metallic elements. Results showed that films with bimetallic elements have an improved behavior in terms of charge transfer observed in the PEC cell, where values of up to 0.8 mA/cm2 were obtained for ZnO with 80 wt% of Al and 20 wt% of Ag (ZnO/80/20). In fact, this film produces the highest amount of hydrogen reaching 53 μmol of H2 after 3 h of reaction because of the synergy presented by the metallic elements, which increases the electron transport due to the longer service life and fast diffusion rate, but also diminish the depletion layer allowing that electrons will have to travel a smaller distance before reacting.