Band-Gap Engineering of NaNbO3for Photocatalytic H2Evolution with Visible Light

Abstract

A new visible light response photocatalyst has been developed for H2evolution from methanol solution by elemental doping. With lanthanum and cobalt dopants, the photoabsorption edge of NaNbO3was effectively shifted to the visible light region. It is also found that the photoabsorption edge is effectively controlled by the dopant concentration. Under visible light irradiation, H2was successfully generated over the doped NaNbO3samples and a rate of 12 μmol·h−1was achieved over (LaCo)0.03(NaNb)0.97O3. Densityfunctional theory calculations show that Co-induced impurity states are formed in the band gap of NaNbO3and this is considered to be the origin of visible-light absorption upon doping with La and Co.