Exfoliation-co-flocculation fabrication of novel porous HTiNbO5/reduced graphene oxide nanocomposites and the photocatalytic performance

A series of novel two-dimensional composites between layered HTiNbO5 and graphene were prepared by exfoliation-co-flocculation process, in which HTiNbO5 and graphene oxide were firstly obtained, and the two components were then delaminated into the corresponding dispersed systems, and further the colloidal solution containing the exfoliated HTiNbO5 single layers was mixed with the colloidal suspension containing the ultrathin graphene oxide (GO) nanosheets, followed by adding HCl solution to flocculate, and then by reduction hydrothermally with hydrazine hydrate. The original HTiNbOs, and the composites between HTiNbO5 and reduced graphene oxide (designated as HTiNbO5/rGO) were structurally characterized by means of XRD, FT-IR, Raman spectroscopy, N-2 adsorption-desorption technique, TEM and SEM. The photo-absorption property of the samples was measured by using DR-UV-Vis technique. The catalytic performance of the original HTiNbO5 and the HTiNbO5/rGO composites for photodegradation of rhodamine B was also investigated. It was found that upon modifying the layered HTiNbO5 with graphene through the exfoliation-co-flocculation way, its visible light response was effectively enhanced, and its photocatalytic activity was improved, in particular that under visible light irradiation. The photocatalytic activity of the HTiNbO5/rGO composites increased with increasing doping amount of graphene.