Exploring the photocatalytic production of hydrogen by Co, Cu or Pd species as co-catalysts supported on a ZnxTiyOz perovskite/TiO2 structure
David Ramírez-Ortega, A. Mantilla, Diana Guerrero-Araque, Jhon Harrison Sierra-Uribe, Luis Lartundo‐Rojas, H.A. Calderón, R. Gómez, Rodolfo Zanella
Abstract
A key factor for improving the performance of the hydrogen photocatalytic reaction is the logical, functional, and effective design of the photogenerated charge transfer through the solid-solid interface in a heterojunction . This point is particularly crucial in cases such as the one of TiO 2 , where a relatively rapid recombination occurs. In this work, a Zn x Ti y O z /TiO 2 heterojunction using the sol-gel nucleation is presented. This method gives rise to a strong and efficient interaction between Zn x Ti y O z and TiO 2 , increasing the photocatalytic activity . Moreover, the addition of Co, Cu or Pd species to the heterojunction surface increases the hydrogen production , due to the strong interaction between them as shown by HRTEM and XPS analyses . Furthermore, the (photo)electrochemical characterization shows that the resistance to charge transfer decreases with co-catalysts, observing the following trend: Pd < Cu < Co. This outcome is related to the mobility and separation of charge carriers and the role played by co-catalysts in hydrogen production .