A comparative study on the photocatalytic hydrogen production of ATiO3 (A = Zn, Cd and Pb) perovskites and their photoelectrochemical properties

In this work, the synthesis of ATiO(3) (A = Zn, Cd, Pb) perovskite materials by solid-state (SS) and solvo-combustion (SC) reactions were performed in order to investigate the influence of the physicochemical properties obtained by the use of different preparation method on the photocatalytic performance for hydrogen generation. The photocatalytic water splitting reaction experiments were carried out with deionized water and the prepared materials under UV light (254 nm) illumination. A series of photoelectrochemical measurements were performed to obtain information about the charge recombination process, the response of the (photo)electrocatalytic activity and the information related to the partial stability of the synthesized materials. The open circuit potential (OCP) and the transient photocurrents revealed the characteristic n-type semiconductor behavior for ZnTiO3 and p-type for CdTiO3 and PbTiO3. The CdTiO3 and PbTiO3 materials prepared by solid-state reaction exhibited superior photocatalytic activity compared to the samples prepared by solvo-combustion reaction. This behavior is associated to uniform particle size which allowed a better photogenerated charge transfer as it was corroborated by photoluminescence and Nyquist analysis. In the case of ZnTiO3 material, the sample synthesized by the solvo-combustion method showed the highest photocatalytic activity (94 mu mol H-2) that is associated to the traces of TiO2 acting as a co-catalyst, for an enhanced charge transfer and decreasing the electron-hole recombination favorable for hydrogen evolution.