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.