An innovative 2D/2D Bi5O7Br/NiFe-LDH Z-scheme heterojunction for enhanced photoreduction CO2 activity

In this study, a novel 2D/2D Z-scheme Bi5O7Br/NiFe-LDH photocatalyst was prepared by combining NiFe-LDH with Bi5O7Br through self-assembly. Under simulated solar irradiation, compared with pure NiFe-LDH and Bi5O7Br, the 2D/2D Z-scheme Bi5O7Br/NiFe-LDH photocatalyst revealed a significant improvement in the efficiency of photocatalytic reduction of CO2. Z-scheme heterojunction promotes the separation of photo generated charge carriers and 2D/2D structure is conducive to exposing more active site and enhancing the migration rate of interface carriers. The photocatalytic activity experiment revealed that the CH4 production efficiency of the Bi5O7Br/NiFe-LDH (37.77 μmol/g/h) after 8 h of light exposure was 2 times and 10 times that of Bi5O7Br (22.41 μmol/g/h) and NiFe-LDH (3.84 μmol/g/h), respectively. The successful formation of Z-scheme heterojunction was determined through band analysis and related characterization. The advantage of Z-scheme heterojunction is that it has high electron mobility and low resistivity. This work launches a feasible design strategy of special structure photocatalysts to enhance the photocatalytic activity for the CO2 reduction.