A high-efficiency Z-scheme Er3+:YAlO3@(Au/SrTiO3)-Au-WO3 photocatalyst for solar light induced photocatalytic conversion of Cr(VI)

A high-efficiency Z-scheme photocatalyst, Er3+:YAlO3@(Au/SrTiO3)-Au-WO3, is fabricated successfully via hydrothermal and photo-deposition methods. All as-prepared samples are characterized by XRD, SEM, TEM, FT-IR, EDX, XPS, Raman spectroscopy, PL and DRS. The activity of the prepared Z-scheme Er3+:YAlO3@(Au/SrTiO3)-Au-WO3 photocatalyst is evaluated through photocatalytic conversion of Cr(VI) under simulated solar light irradiation. The meaningful influencing factors such as simulated solar light irradiation time, light intensity, sacrificial agents and cycling times are investigated. The results displayed that the existence of Er3+:YAlO3 can improve the utilization ratio of solar light for wide band-gap SrTiO3. Moreover, the formation of Z-scheme SrTiO3/WO3 photocatalytic system and the introduction of Au nanoparticles as electron mediator and co-catalyst can promote the separation of photo-induced electron and hole to obtain much high photocatalytic activity. Finally, the mechanism on conversion of Cr(VI) caused by Z-scheme Er3+:YAlO3@(Au/SrTiO3)-Au-WO3 photocatalyst is put forward. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A high-efficiency Z-scheme photocatalyst, Er3+:YAlO3@(Au/SrTiO3)-Au-WO3, was successfully fabricated using hydrothermal and photo-deposition methods. The presence of Er3+:YAlO3 improved the utilization of solar light for wide band-gap SrTiO3, and the introduction of Au nanoparticles promoted the separation of photo-induced electrons and holes, resulting in enhanced photocatalytic activity for Cr(VI) conversion under simulated solar light irradiation.