MgTiO3/MgTi2O5/TiO2 heterogeneous belt-junctions with high photocatalytic hydrogen production activity

An effective photocatalytic hydrogen production catalyst comprising MgTiO3/ MgTi2O5/TiO2 heterogeneous belt-junctions was prepared using magnesium ions by a thermally driven doping method. The tri-phase heterogeneous junction was confirmed by X-ray powder diffraction （XRD）, transmission electron microscopy （TEM）, and high-resolution TEM （HRTEM）. The as-prepared MgTiOg/MgTi2OJ TiO2 heterojunctions exhibited a very high photocatalytic hydrogen production activity （356.1 mol·g0.1mgcat·h^-1） and an apparent quantum efficiency （50.69% at 365 nm） that is about twice of that of bare TiO2 nanobelts （189.4mol·g0.1mgcat·h^-1）. Linear sweep voltage and transient photocurrent characterization as well as analysis of the electrochemical impedance spectra and Mott-Schottky plots revealed that the high photocatalytic performance is caused by the one-dimensional structure, which imparts excellent charge transportation characteristic, and the MgTiO3/MgTi2O5/TiO2 tri-phase heterojunction, which effectively drives the charge separation through the inherent electric field. This titanate-based tri-phase heterogeneous junction photocatalyst further enriches the catalyst system for photocatalytic hydrogen production.