title: TiO2/BiVO4 Nanowire Heterostructure Photoanodes Based on Type II Band Alignment.
abstract: Metal oxides that absorb visible light are attractive for use as photoanodes in photoelectrosynthetic cells. However, their performance is often limited by poor charge carrier transport. We show that this problem can be addressed by using separate materials for light absorption and carrier transport. Here, we report a Ta:TiO2|BiVO4 nanowire photoanode, in which BiVO4 acts as a visible light-absorber and Ta:TiO2 acts as a high surface area electron conductor. Electrochemical and spectroscopic measurements provide experimental evidence for the type II band alignment necessary for favorable electron transfer from BiVO4 to TiO2. The host-guest nanowire architecture presented here allows for simultaneously high light absorption and carrier collection efficiency, with an onset of anodic photocurrent near 0.2 V vs RHE, and a photocurrent density of 2.1 mA/cm(2) at 1.23 V vs RHE.
authors.affiliation: Department of Chemical Engineering and Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: Joaquin
authors.initials: J
authors.lastname: Resasco
authors.affiliation: Department of Chemical Engineering and Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Chemical Engineering and Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: Nikolay
authors.initials: N
authors.lastname: Kornienko
authors.affiliation: Department of Chemical Engineering and Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: Nigel
authors.initials: N
authors.lastname: Becknell
authors.affiliation: Department of Physics, Kangwon National University , Chuncheon-si, Gangwon-do 200-701, South Korea.
authors.forename: Hyunbok
authors.initials: H
authors.lastname: Lee
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Polymer Science & Engineering, Conte Polymer Research Center, University of Massachusetts , Amherst, Massachusetts 01003, United States.
authors.forename: Alejandro L
authors.initials: AL
authors.lastname: Briseno
authors.affiliation: Department of Chemical Engineering and Department of Chemistry, University of California, Berkeley, California 94720, United States; Materials Sciences Division and Kavli Energy NanoSciences Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States; Materials Sciences Division and Kavli Energy NanoSciences Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Peidong
authors.initials: P
authors.lastname: Yang