Ce-doped ZnO (CexZn1−xO) becomes an efficient visible-light-sensitive photocatalyst by co-catalyst (Cu2+) grafting†
Abstract
We have fabricated an efficient visible-light-sensitive Cu2+-grafted Ce-doped ZnO photocatalyst (Cu2+–CexZn1−xO) by adopting a metal ion doping and co-catalyst modification. Impurity states were formed below the conduction band (CB) edge in CexZn1−xO, and these impurity states induce the visible-light absorption. CexZn1−xO without a Cu2+-co-catalyst showed negligible visible-light activity due to the low reduction power of electrons in impurity levels. Surprisingly, Cu2+-modification over CexZn1−xO drastically increased its visible-light activity. Excited electrons in impurity states can transfer to the Cu2+-ions on the surface and form Cu2+/Cu+ redox couples, which cause the efficient oxygen