Construction of novel Z-scheme Cu2O/graphene/α-Fe2O3 nanotube arrays composite for enhanced photocatalytic activity

Abstract Novel Z-scheme Cu 2 O/graphene/α-Fe 2 O 3 nanotube arrays (Cu 2 O/G/FNA) composite was synthesized by facile electrochemical processes for the first time. Compared to single- (1C) or two-component (2C) system, three-component (3C) Z-scheme composite material exhibited the efficient photogenerated electron-hole separation as well as the sufficient redox potential via directly quenching between the weak oxidative holes and reductive electrons after Z-scheme charge transfer. The photoelectrochemical measurements and photocatalytic degradation of methylene blue by Cu 2 O/G/FNA under visible-light irradiation demonstrated the enhanced photoactivity and photostability compared to 1C, 2C, and 3C non-Z-scheme system. The Z-scheme photocatalytic mechanism was confirmed based on the relative characterizations and radical trapping experiments over Cu 2 O/G/FNA and G/Cu 2 O/FNA composites, also indicating that •O 2 − radicals was the prime active species over Cu 2 O/G/FNA. In addition, G-sheet layer as an efficient electron mediator plays a key role in the construction of Z-scheme 3C composite photocatalyst.