Fabrication of flower spherical-like Z-scheme FeWO4/NiAl-LDH photocatalysts with excellent activity for CO2 photoreduction under visible light

Abstract

In recent years, photocatalytic reduction of carbon dioxide technology has been considered as an effective approach to moderate the energy crisis. In order to achieve efficient reduction of CO2, direct Z-scheme heterostructure composed of NiAl-LDH flower-like sphere and FeWO4 nanoflakes (FWLDH) were obtained through a facile hydrothermal strategy. The prepared FWLDH photocatalysts revealed outstanding performance for CO2 photoreduction to CO under the irradiation of visible light. The 10%FWLDH possessed the optimal photocatalytic CO yield (5 μmol· g−1·h−1), reaching up to 2.4 folds higher than that of pristine LDH (2.1 μmol·g−1·h−1). In addition, the CO selectivity was more than 93% over hydrogen evolution from the side reaction of water reduction. Finally, EPR characterization indicated that the electron transfer mechanism of FWLDH catalyst conformed to the Z-scheme pattern. The effective separation of the light-induced electron-hole pairs and the enhancement of the photoelectron reduction ability at the NiAl-LDH conduction band were the reasons for the prominent improvement of the photocatalytic performance of NiAl-LDH. This research could provide a novel perspective for designing photocatalyst with high efficiency for CO2 photoreduction.