Phase transition-induced band edge engineering of BiVO4 to split pure water under visible light.
Through phase transition-induced band edge engineering by dual doping with In and Mo, a new greenish BiVO4 (Bi1-XInXV1-XMoXO4) is developed that has a larger band gap energy than the usual yellow scheelite monoclinic BiVO4 as well as a higher (more negative) conduction band than H(+)/H2 potential [0 VRHE (reversible hydrogen electrode) at pH 7]. Hence, it can extract H2 from pure water by visible light-driven overall water splitting without using any sacrificial reagents. The density functional theory calculation indicates that In(3+)/Mo(6+) dual doping triggers partial phase transformation from pure monoclinic BiVO4 to a mixture of monoclinic BiVO4 and tetragonal BiVO4, which sequentially leads to unit cell volume growth, compressive lattice strain increase, conduction band edge uplift, and band gap widening.
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139;
Won Jun
WJ
Jo
Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea;
Hyun Joon
HJ
Kang
Korea Institute of Chemical Technology, Daejeon 305-343, Korea;
Ki-Jeong
KJ
Kong
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139;
Yun Seog
YS
Lee
Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea;
Hunmin
H
Park
Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea;
Younghye
Y
Lee
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139;
Tonio
T
Buonassisi
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139;
Karen K
KK
Gleason
School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798, Korea jlee1234@unist.ac.kr.
Jae Sung
JS
Lee
band edge engineering; bismuth vanadate; dual doping; photocatalysis; water splitting