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

Authors :: Borse, Pramod H.
Joshi, Upendra A.
Sang Min Ji
Jum Suk Jang
Jae Sung Lee
Euh Duck Jeong
Hyun Gyu Kim
Source :: Applied Physics Letters; 1/15/2007, Vol. 90 Issue 3, p034103, 3p, 4 Graphs
Publication Year :: 2007
Abstract: The Pb substitution effect was investigated experimentally and theoretically on the crystal structure of BaSnO<subscript>3</subscript> and on the photo-oxidation activity of H<subscript>2</subscript>O. The chemically doped Pb in BaSnO<subscript>3</subscript> induced a concentration-dependent redshift of the experimental band gap (BG). The BaPb<subscript>0.8</subscript>Sn<subscript>0.2</subscript>O<subscript>3</subscript> system produced 32 μmol/h of O<subscript>2</subscript> under λ>=420 nm photons, but no O<subscript>2</subscript> for BaSnO<subscript>3</subscript>. The DFT calculations of BaPb<subscript>x</subscript>Sn<subscript>1-x</subscript>O<subscript>3</subscript> (x=0,0.5,1) by using generalized approximation, implying the BG alteration and the photocatalytic activity of BaPb<subscript>x</subscript>Sn<subscript>1-x</subscript>O<subscript>3</subscript>, are due to the induced Pb 6s orbital in the BG of BaSnO<subscript>3</subscript>. Thus Pb modified the insulating nature of BaSnO<subscript>3</subscript> to semiconducting and semimetallic. [ABSTRACT FROM AUTHOR]