Cu2O/Ti3C2MXene heterojunction photocatalysts for improved CO2 photocatalytic reduction performance

Photocatalytic CO 2 reduction has been viewed as a promising approach to relieve the energy crisis and green-house effect. Cheap and high performance cocatalyst is an effective approach to enhance the photocatalytic activity . Ti 3 C 2 T x (MXene) is a new family of 2D layered materials, which can be served as an electron conductor. In this work, Cu 2 O/Ti 3 C 2 T x heterojunction composites were prepared by in situ hydrothermal growth method. Cu 2 O/Ti 3 C 2 T x with the different percentages of ultrathin Ti 3 C 2 T x (2, 5, 10, 20 and 30 mg) nanosheet in the heterostructured catalysts are noted as CuTi-X (X = 2, 5, 10, 20, 30). As prepared CuTi-10 exhibits the highest photocatalytic CO 2 reaction activity (17.55 μmol·g −1 ·h −1 for CO and 0.96 μmol·h −1 ·g −1 for CH 4 ), which is 3.1 and 4.0 times higher than that of pure Cu 2 O (5.73 μmol·g −1 ·h −1 for CO and 0.24 μmol·g −1 ·h −1 for CH 4 , respectively). The advantage of the in situ growth endows the Cu 2 O/Ti 3 C 2 T x heterojunction contact interface, which is conductive to the separation of photogenerated electrons-hole pairs. The main reason is analysed and can be attributed to that Ti 3 C 2 T x can served as an electron acceptor due to its excellent conductive properties, rendering that more photo generated electrons attend the CO 2 reduction reaction. This provides a strategy to construct the Cu 2 O/Ti 3 C 2 T x heterojunction for photocatalytic CO 2 reduction.