Constructing outstanding 1D/2D Co3O4/NiMnO3 heterostructure to promote the PEC efficiency for water pollution remediation

Abstract

The structural design and morphology control of materials is a very attractive topic because the structure and morphology of materials usually play a key role for their performance and application. In this work, we report a facile two-step hydrothermal process for construction of the binary composite oxide system (i.e., 1D/2D Co3O4/NiMnO3 core-shell heterostructure) based on Ostwald ripening effect. Interestingly, Co3O4 nanowire will expand only when it is fully covered with NiMnO3 nanosheets to form a core-shell structure in sequential hydrothermal process. In binary composite oxide system, the formation of continuous and uniform interface between core (Co3O4) and shell (NiMnO3) based on Ostwald ripening effect is the key factor in the heterogeneous nucleation process, which can be proved by the homogeneous diffusion of Co element in the Ti/Co3O4-NiMnO3 sample. As a result, the optimized Ti/Co3O4-NiMnO3-1.5 exhibited superior PEC performance (degradation rates are ∼ 91.2% for 120 min and 80.5% after 5 cycles) for degrading reactive brilliant blue KN-R solution, which can be attributed to the construction of the hollow Co3O4/NiMnO3 core-shell heterostructure. Furthermore, the identification experiments of active species showed that the h+ and •O2- radicals are the dominant reactive species, indicating the induced charge transfer is based on the type II semiconductor heterostructure.