Lanthanum chromite for visible light-driven photocatalytic hydrogen evolution

Lanthanum chromite (LaCrO3) photocatalysts have been successfully prepared via a sol-gel route followed by thermal treatment through calcination in air atmosphere. The structures and properties of the as-prepared samples are examined with various techniques, including synchrotron X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). Their photocatalytic activity on hydrogen evolution from aqueous methanol solution is investigated under visible light (lambda > 400 nm). Results show that the local structures and chemical states of the cations, La3+ and Cr3+, are insensitive to the calcination temperature, as confirmed by XANES and EXAFS. The highest hydrogen evolution rate is achieved by the LaCrO3 sample calcined at 1100 degrees C and loaded with 0.01 wt% N co-catalyst, which is 2.11 mu mol/h.