Direct Z-scheme heterojunction of CdS/UiO-66 (Ce) for boosting photocatalytic CO2 reduction to CO with efficient charge transfer

Photocatalytic CO 2 reduction has been widely recognized as an exceptionally promising technique for converting carbon dioxide into high-value-added chemicals. Metal-organic frameworks (MOFs) have emerged as promising photocatalysts for visible-light-driven CO 2 reduction owing to their unique structural advantages, but the achieved efficiency is still not satisfying. Herein, we successfully constructed CdS/UiO-66(Ce) Z-Scheme heterojunction photocatalysts by in situ growth of CdS nanoparticles on an octahedral UiO-66(Ce) substrate. The morphology, physicochemical properties, and photoelectric characteristics of the prepared samples were systematically characterized in detail. Photocatalytic activity results indicated that the prepared heterostructure could efficiently reduce CO 2 to CO, and its activity was significantly superior to that of pristine UiO-66 (Ce) and CdS. Under illumination of visible light, the optimal as-prepared sample achieved a CO yield of 134.3 μmol g −1 h −1 , which was 168.6 and 2.62 times higher than that of pure UiO-66(Ce) and CdS, respectively. The reinforced photocatalytic CO 2 reduction to CO activity can be ascribed to the obviously improved visible-light harvesting and effectively facilitated the separation and migration of photogenerated charge carriers via a Z-scheme charge transfer. This study may well present a novel design strategy of highly efficient MOFs-based Z-scheme photocatalytic systems for photocatalytic CO 2 reduction.