Visible-light-driven photocatalytic properties of Nb2C/Bi2WO6 hybrids with 2D/2D structure for efficient pollutant removal

Sunlight-driven photocatalysis is a promising method for the efficient removal of pollutants. However, most photocatalysts only adsorb and utilize part of the sunlight. In this work, as a typical MXenes material with broadband adsorption of sunlight, Nb2C nanosheets were obtained by etching Nb2AlC, and the Nb2C/Bi2WO6 hybrids (NB2 and s-NB2) with different coupling interfaces were prepared by in situ growth synthesis and selfassembly method, respectively. In addition, Nb2C nanosheets as co-catalysts were tightly combined with Bi2WO6 nanoflakes to ultimately construct a unique 2D/2D structure, which can reduce the carrier transport distance and increase the interfacial contact area. Moreover, the obtained hybrids exhibited significant improvements in the adsorption capacity and photocatalytic efficiency under visible light irradiation compared with pure Bi2WO6. Furthermore, the photodegradation rate constants for methylene blue (MB) of NB2 and s-NB2 were 0.0945 and 0.0506 min-1, respectively, which were 2.96 and 1.59 times higher than those of pure Bi2WO6. In particular, the hybrids prepared by in-situ growth synthesis (NB2) showed a higher photocatalytic efficiency for the treatment of organic contaminants due to the formed tighter interface. Therefore, this work could provide efficient catalyst configuration with ultrathin 2D/2D structure by using different methods, and demonstrate that Nb2C can serve as an effective co-catalyst for enhanced photocatalytic performance.