Band gap tuning of lead-substituted BaSnO₃ for visible light photocatalysis

The Pb substitution effect was investigated experimentally and theoretically on the crystal structure of BaSn O3 and on the photo-oxidation activity of H2 O. The chemically doped Pb in BaSn O3 induced a concentration-dependent redshift of the experimental band gap (BG). The Ba Pb0.8 Sn0.2 O3 system produced 32 μmolh of O2 under λ420 nm photons, but no O2 for BaSn O3. The DFT calculations of Ba Pbx Sn1-x O3 (x=0,0.5,1) by using generalized approximation, implying the BG alteration and the photocatalytic activity of Ba Pbx Sn1-x O3, are due to the induced Pb 6s orbital in the BG of BaSn O3. Thus Pb modified the insulating nature of BaSn O3 to semiconducting and semimetallic.