Photocatalytic hydrogen production using bimetallic and trimetallic hydrotalcite as photocatalysts

Abstract

• Bimetallic and trimetallic hydrotalcites were synthesized by coprecipitation method. • The formation of 2D structure characteristic of this type of material was observed. • The chemical composition was determined by XPS and FTIR analysis. • A difference in the positions of VB and CB was observed between both hydrotalcites. • Both hydrotalcites presented a higher production of H 2 than TiO 2. Bimetallic ZnAl and trimetallic ZnCuAl hydrotalcites were synthesized using the coprecipitation method. The presence of the characteristic peaks of layered double hydroxide phases was observed by XRD analysis, as well as the typical like flower morphology of these materials by FESEM and HRTEM analysis. Changes in the valence and conduction bands position, as well as in the band gap calculated by UV-vis spectroscopy and XPS techniques was noted by the presence of Cu in the material. In the photocatalytic behavior for H 2 production in presence of UV irradiation, ZnCuAl hydrotalcite showed the highest yield of H 2 in comparison to ZnAl material, being both photocatalysts more actives that the reference photocatalyst, consisting in commercial TiO 2 (Degussa P-25).