Effect of Lactic Acid on the Photoelectrocatalytic Water Splitting of Hematite Prepared by Hydrothermal Method

The photoelectrocatalytic water splitting performance of the pristine hematite is limited because of its poor bulk charge separation efficiency. In this study, the lactic acid modified hematite films were grown in situ on Fluorine-doped tin oxide substrates by hydrothermal method and then annealed in nitrogen atmosphere. At 1.5 V versus RHE, the photocurrent density of the optimal lactic acid modified hematite photoanode (0.075LA-Fe 2 O 3 ) was 1.5 mA cm − 2 , which was three times that of the based hematite (0.5 mA cm − 2 ). The enhanced photoelectrocatalytic performance of the lactic acid modified hematite was attributed to its increased bulk charge separation efficiency caused by the oxygen vacancies and island-like pattern, as well as its improved surface charge injection efficiency. The effect of lactic acid on the morphology, crystalline structure and photoelectrocatalytic performance of the hematite photoanode are studied by systematical characterization. Graphic abstract