The role of cobalt to control the synthesis of nanoscale Co/UiO‐66 composite for photocatalysis

Abstract Restricted synthesis of nanoscale metal–organic frameworks (MOFs) is highly desirable for optimizing their performance and extending their applications. In the present work, Co was utilized as an additive for the mixture of zirconium‐based MOF adding of Co. We found a significant effect on reducing the crystal size of UiO‐66 by increasing the Co additive. The X Co/UiO‐66 composites, where X refers to the weight percentage, were characterized by XRD, SEM, BET, UV, TGA, and DTA. Consequently, well‐dispersed nanoscale UiO‐66 crystals of nanocrystal size can be easily synthesized by adding Co. Such a difficult process involves a couple of equivalent mechanisms, one is related to the adsorption of the coloring into the pores of the MOF, whereas the other mechanism is that the adsorption capacity and photocatalytic performance of X Co/UiO‐66 nanoparticles are higher than those of pristine UiO‐66. Furthermore, increasing the Co additive can reduce the bandgap of the material; therefore, it enhances the photocatalytic performance. The synthesized nanoscale UiO‐66 crystals exhibit a high degree of crystallinity and porosity.