Novel heterojunction photocatalysts based on lanthanum titanate nanosheets and indium oxide nanoparticles with enhanced photocatalytic hydrogen production activity

Abstract

A lanthanum titanate (La₂Ti₂O₇) and indium oxide (In₂O₃) heterojunction nanocomposite is synthesized by a solvothermal method. The crystal phase, morphology, optical absorption activity and chemical composition of the In₂O₃/La₂Ti₂O₇ heterojunction nanocomposites are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectra and X-ray photoelectron spectroscopy. The results reveal that the In₂O₃ nanoparticles are uniformly dispersed on the surface of the La₂Ti₂O₇ nanosheets with good adhesion. The In₂O₃/La₂Ti₂O₇ nanocomposite with a molar ratio of 1.5 : 1 exhibits the highest H₂ production rate when used in photocatalytic water splitting, improved by 29.62 and 6.43 times relative to pure In₂O₃ and La₂Ti₂O₇, respectively. The enhanced photocatalytic H₂ production rate can be ascribed to the formation of the heterojunction structure, which results from the homogeneous dispersion of In₂O₃ nanoparticles on La₂Ti₂O₇ nanosheets. The configuration of the In₂O₃/La₂Ti₂O₇ heterojunction nanocomposite photocatalyst can promote the fast separation of photogenerated carriers in space and improve the rate of water-splitting to form H₂.