Hollow Mo2C nanospheres modified B-doped g-C3N4 for high efficient photocatalysts

Abstract Although graphitic carbon nitride (g-C 3 N 4 ) is one of the most promising metal-free semiconductors in the field of photocatalytic hydrogen production, the preparation of efficient g-C 3 N 4 -based photocatalysts is still a challenge. Herein, the strategy of element doping and co-catalyst loading are employed to make an effective modification on g-C 3 N 4 . The Mo 2 C hollow nanospheres supported by porous B-C 3 N 4 (B-doped g-C 3 N 4 ) flakes, namely, B-C 3 N 4 /Mo 2 C photocatalysts are successfully constructed by the ultrasonic self-assembly-calcination approach. The unique Mo 2 C hollow nanospheres structures increases internal multiple visible light scattering, which facilitates light-harvesting, shortens the transport distance of carriers, and hence reduces the carriers recombination. Impressively, B-C 3 N 4 /Mo 2 C-35 exhibits excellent activity in photocatalytic hydrogen production, affording an H 2 production rate up to 1696.4 µ mol g −1 h −1 , which is higher than B-C 3 N 4 /3 wt% Pt photocatalyst. Moreover, the apparent quantum efficiency of B-C 3 N 4 /Mo 2 C-35 at 420 nm is 2.12%. Mechanism studies suggest that this desired photocatalytic performance is attributed to a broader light absorption range, more reactive sites and faster carrier transfer rate than that of pure g-C 3 N 4 . This work develops a noble metal-free hollow nanosphere co-catalyst system and proposes new insight into the design of g-C 3 N 4 -based composite photocatalysts.