Magnetic and ultrasonic integrated photocatalytic hydrogen evolution effects with Nanosize CoOCu2OZnO and TiO2 decorated on reduced graphene oxide

In this study, metal oxide composite (CoOCu2OZnO) and TiO2 on graphene oxide composite (CCZ− G− T) were
synthesized to improve visible light-driven H2 evolution through the addition of a cation scavenger, ultrasonic
effect, and magnetic field effect. The synthesized nanocomposites were characterized through structural, surface, and electrochemical analyses with band structure. The photocatalyst showed hydrogen production of 792
μmol⋅g− 1 for 4 hours. Moreover, this CCZ− G− T photocatalyst exhibits relatively high photocatalytic activity at
(530− 810) μmol⋅g− 1 when using a scavenger, 1,190 μmol⋅g− 1 when using a magnetic field of 0.14 T, and 1,230
μmol⋅g− 1 when using ultrasonic waves. The CCZ− G− T composite exhibited 630 μmol⋅g− 1 under a magnetic field
condition of 0.14 T for 1 hour, which was significantly higher than the hydrogen production rate of 510 μmol⋅g− 1
under ultrasonic conditions. The current study provides new insights into the magnetic field effect on the
hydrogen evolution reaction (HER) of graphene-based photocatalysts.