Facile synthesis of 2D Bi4O5Br2/2D thin layer-Ti3C2 for improved visible-light photocatalytic hydrogen evolution

Photocatalytic hydrogen evolution via water splitting was considered as a promising way of solar energy conversion and storage in the past decades. However, the weak visible-light response and fast recombination of electron-hole pairs are still main obstacles to overcome. Herein, a novel 2D/2D Bi 4 O 5 Br 2 /TL-Ti 3 C 2 (Thin layer-Ti 3 C 2 ) visible-light photocatalyst was successfully prepared by in-situ synthesis of Bi 4 O 5 Br 2 nanosheets on the surface of TL-Ti 3 C 2 at room temperature . The resulting Bi 4 O 5 Br 2 /TL-Ti 3 C 2 exhibits a higher hydrogen evolution activity (83.5 ​μmol·g −1 ·h −1 ) than that of pristine Bi 4 O 5 Br 2 (44.9 ​μmol·g −1 ·h −1 ) under visible-light irradiation. The enhanced hydrogen evolution activity of as-prepared photocatalyst mainly attributes to the increased visible light responsiveness and rapid transfer of photo-induced electrons. The strong interaction between TL-Ti 3 C 2 and Bi 3+ in Bi 4 O 5 Br 2 nanosheets establishes a good electron transfer channel and close contact, which accelerates the transfer of photo-induced electrons from Bi 4 O 5 Br 2 to Ti 3 C 2 and promotes the separation of photo-generated charge carriers, thereby increasing the number of effective photo-induced electrons involved in the hydrogen evolution. This work provides a new insight into the construction of Bi x O y Br z /MXene photocatalyst system, and demonstrated that Ti 3 C 2 has excellent application potential in promoting the photocatalytic performance of bismuth-rich bismuth oxyhalides (Bi x O y X z X ​= ​Cl, Br, I).