BiVO4 /Bi4Ti3O12 heterojunction enabling efficient photocatalytic reduction of CO2 with H2O to CH3OH and CO

Construction of composite semiconductors is an effective solution to elevate the efficiency of photocatalysis by prolonging lifetime of photogenerated hole and electrons. Herein, a heterojunction structure composite BiVO 4 /Bi 4 Ti 3 O 12 was synthesized via a facile in situ hydrothermal condition. The novel composite photocatalyst has excellent photocatalytic ability to reduce CO 2 with H 2 O into CH 3 OH and CO. The BiVO 4 /10 % Bi 4 Ti 3 O 12 sample shows the highest yields of CH 3 OH and CO up to 16.6 and 13.29 μmol g −1  h −1 , which was 12.39 and 5.68 times higher than that of pure BiVO 4 , and 9.88 and 2.80 times higher than that of pure Bi 4 Ti 3 O 12 , respectively. Such a high activity is attributed to the type II heterojunction structure which significantly enhances separation of photogenerated carriers and promotes collaboration between the water oxidation on the Bi 4 Ti 3 O 12 and the CO 2 reduction on BiVO 4 . The photocatalytic reaction mechanism of CO 2 on the composite was proposed according to experiment results.