The hydrothermal and solvothermal synthesis of LiTaO₃ photocatalyst: Suppressing the deterioration of the water splitting activity without using a cocatalyst

Abstract LiTaO₃ photocatalysts having high water splitting activity in the absence of cocatalyst were synthesized using hydrothermal and solvothermal methods. The particle size of the hydrothermally synthesized LiTaO₃ was 500-3000 nm, and the H₂ generation rate under ultraviolet irradiation without cocatalyst was as low as 8 μmol/h. Conversely, LiTaO₃ synthesized by the solvothermal method using acetone as the solvent showed high H₂ generation rate of over 600 μmol/h. The Brunauer-Emmett-Teller surface area of the solvothermally synthesized LiTaO₃ was 23.7 m²/g, and the particle size was 10-30 nm. In the long-term water splitting experiment on the LiTaO₃ synthesized by the solvothermal method, the H₂ generation rates did not change for 30 d, and the catalytic turnover number was 510.