Synergistic RGO/Black TiO2/2D-ZIF-8 Ternary Heterogeneous Composite with Highly Efficient Photocatalytic Activity

摘要

A ternary heterogeneous composite combining reduced gra-phene oxide (RGO), black titanium dioxide (BTiO2) nanosheets and two dimensional ZIF-8 sheets (2D-ZIF-8) was prepared. Under hydrothermal condition, BTiO2 nanosheets and GO were tightly bound together, and meanwhile GO was reduced to RGO. Upon mixing with poly (vinyl pyrrolidone) (PVP)-modified 2D-ZIF-8, the RGO/BTiO2/2D-ZIF-8 ternary composite was obtained by PVP binding between BTiO2 and 2D-ZIF-8. The introduction of 2D-ZIF-8 endowed the ternary composite a good adsorption capability of contaminant and followed degradation in situ at the site of adsorption. Owing to synergistic catalysis of oxygen vacancy and the formation of double heterogeneous interfaces, the prepared ternary composite had good visible light adsorption and rapid charge separation rate, which improved the photocatalytic performance. The rate constant of photocatalytic degradation of doxycycline hydrochloride and methylene blue by RGO/BTiO2/ 2D-ZIF-8 was determined to be 0.0118 and 0.0232 min~(-1), respectively, which are 2.68 and 3.3 times that of BTiO2. This study could provide deep insight for the design of high and bi-functional activity catalysts based on the assembly of two-dimensional sheet.