Constructing NiFe-LDH wrapped Cu2O nanocube heterostructure photocatalysts for enhanced photocatalytic dye degradation and CO2 reduction via Z-scheme mechanism

Considering the flexible chemical composition, tunable electronic properties and unique two-dimensional structure of layered double hydroxides (LDHs), we constructed NiFe-LDH/Cu2O heterostructure photocatalysts. The photocatalytic performance of NiFe-LDH/Cu2O heterostructure photocatalysts was evaluated by methyl blue (MB) degradation and CO2 reduction under visible-light illumination. The removal efficiency of MB was improved from 20% for Cu2O and 45% for NiFe-LDH to 93% for NiFe-LDH/Cu2O after 30 min adsorption and 240 min visible-light irradiation. Moreover, CH4 yield from CO2 reduction over NiFe-LDH/Cu2O is about 5.6 and 6.9 times that of NiFe-LDH and Cu2O, respectively. Based on a detailed study of structural, electronic, optical and electrochemical properties, Z-scheme photocatalytic mechanism was proposed to explain the enhanced photocatalytic performance of NiFe-LDH/Cu2O. This work presents an inexpensive and flexible strategy for manufacturing heterostructure photocatalysts using earth-abundant elements. (C) 2020 Elsevier B.V. All rights reserved.