Photocatalytic activity enhancement of LaPO4via surface oxygen vacancies
A monoclinic LaPO4 photocatalyst with surface oxygen vacancies (v-LaPO4) was prepared using hydrothermal and vacuum heat treatment methods. The photocatalytic activity reached a maximum 350 °C with vacuum heat treatment for 3 h and the photocatalytic activity and photocurrent of v-LaPO4 were almost 1.6 and 2.3 times higher than that of pure LaPO4, respectively. The improvement of the photocatalytic activity is attributed to the high separation efficiency of photogeneration electron–hole pairs. The main oxidative species are hydroxyl radicals. The photocatalytic activity of v-LaPO4 for the degradation of MB does not decrease after four cycles, indicating that the v-LaPO4 photocatalyst has good stability.