Growth of binary anatase–rutile on phosphorylated graphene through strong P–O–Ti bonding affords a stable visible-light photocatalyst

Abstract

Phosphorylated graphene sheets covalently bind, grow and stabilize biphasic anatase–rutile clusters through strong P–O–Ti bridges. The resulting nanocomposites stands as efficient visible-light photocatalysts for the degradation of dyes from water.

The solvent-free mechano-chemical grinding of a bifunctional P25–graphene oxide adsorbent–photocatalyst and its configuration as porous beads

“…This trend is expected for photocatalysis under visible light, as P25 Degussa do not display any appreciable activity. 23 In turn, graphene oxide brings additional adsorption sites 18 and also acts as a photosensitizer for titanium dioxide. 24 Within the dye series, the degradation of methylene blue and malachite green seems to be more quantitative (∼90% degradation reached with TiO 2 @GO-05 : 95).…”

“…The first material was prepared through the post-grafting of titanium alkoxide onto graphene oxide 22 followed by thermal annealing treatment to generate crystalline titanium dioxide grown on the external surface of graphene. 23 The second photocatalyst was prepared via mixing chitosan and titanium alkoxide in a sol–gel process followed by carbonization under nitrogen to generate well-entangled titanium dioxide inside of the carbonaceous graphene network (see the Experimental section for details and Fig. S4 † for more characterization data).…”

“…The outstanding adsorptive capacity of TiO 2 @GO_sol–gel with respect to TiO 2 @GO-45 : 55 can be explained based on differences in their specific surface areas, as estimated by nitrogen sorption; the former has a value of 186 m 2 g −1 , while a value of only 41 m 2 g −1 was recorded for the mechanically ground material. Although interesting, it is worth mentioning that TiO 2 @GO_sol–gel was prepared through a multistep procedure 22 involving expensive precursors and calcination at high temperature, 23 while a very trivial mechanical grinding procedure was applied in the case of TiO 2 @GO-45 : 55 ( Fig. 5b ).…”