Hydrothermal synthesis and photocatalytic properties of bismuth molybdate materials

摘要

The three kinds ofwell-known bismuth molybdates α-Bi_2Mo_3O_(12), β-Bi_2Mo_2O_9, and γ-Bi_2MoO_6 have been prepared employing mild hydrothermal methods. By tuning the Bi/Mo ratio and pH values, controlling formation of bismuth molybdates can be achieved. Low pH and high concentration of molybdenum lead to the formation of a-Bi_2Mo_3O_(12). High pH and high concentration of bismuth lead to the formation of 7-Bi_2MoO_6. The pure form of the β-phase can be prepared by calcining the hydrothermal product at 560 ℃. Photophysical and photocatalytic studies show that Aurivillius structure γ-Bi_2MoO_6 shows an intense absorption band in the visible light region and better photocatalytic activity than α-Bi_2Mo_3O_(12) and β-Bi_2Mo_2O_9 under visible light irradiation. The factors that result in different photocatalytic activities for three kinds of photocatalysts are discussed.