Pure phase orthorhombic MgTi2O5 photocatalyst for H2 production

Abstract

An undesirable phase transformation was overcome and pure phase orthorhombic MgTi₂O₅ nanocrystals were facilely prepared. The concentration of metal ions and the reaction temperature are the two factors that were found to affect the phase transformation of the magnesium titanates. The as-prepared pure phase MgTi₂O₅ nanocrystals possessed a high crystallinity and were 20 nm in diameter. They exhibited excellent photocatalytic hydrogen production activity (418 μmol h⁻¹), and high apparent quantum efficiency (62.5% at 313 nm and 50.6% at 365 nm, respectively). Significantly, a “solar-to-hydrogen” efficiency of 0.52% was obtained. This may be attributed to the pure phase crystals and large surface area, which favored charge transfer and promoted photo-induced charge separations which is proven using photoelectrochemical measurements.