Sodium-doped La2Ti2O7 synthesized by molten salt synthesis method for photocatalytic overall water splitting

Solar-driven hydrogen production through water splitting is currently one of the research hotspots nowadays. Lanthanum titanate (La 2 Ti 2 O 7 ) is one kind of layered-structure perovskite photocatalyst and possesses a superior electronic structure for photocatalytic overall water splitting. However, it suffers from several drawbacks, such as poor photo absorption and easy recombination of photogenerated charge carriers. In this study, sodium (Na) ion-doped La 2 Ti 2 O 7 with plate-like crystal morphology was synthesized by using molten salt synthesis (MSS). The XRD and TEM results indicated that the MSS method enhanced the crystallinity of La 2 Ti 2 O 7 . UV-vis, Raman and EPR spectra disclosed that Na doping through MSS introduced oxygen vacancies. The Na (0.3   mol%)-doped La 2 Ti 2 O 7 (MSS) provided the optimal hydrogen evolution rate, and the value was 6.43 times greater than that of pure La 2 Ti 2 O 7 synthesized by traditional solid-state reaction method. The synergistic effect of crystal facet engineering and defect engineering remarkably enhanced the photocatalytic activity of La 2 Ti 2 O 7 .