| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 65238 | Journal of Molecular Catalysis A: Chemical | 2015 | 8 Pages |
•Graphene sheets and ribbons show variant effect on photocatalysis in composite.•TiO2/graphene sheets or ribbons exhibit higher photocatalytic efficiency.•The composite of TiO2 and graphene sheets exhibits best photocatalytic activity.•Rectangular TiO2 sheets are dominated with a larger percentage of {0 0 1} facets.•Graphene oxide sheets/ribbons were photoreduced by TiO2 under UV irradiation.
To investigate the effect of graphene sheets and ribbons on photocatalysis, the composite of anatase TiO2 nanosheets (TiO2-NS) and graphene materials was prepared. Graphene oxide sheet (GOS) was synthesized by a modified Hummers’ method, and graphene oxide ribbon (GOR) was formed by unzipping carbon nanotubes. UV–vis absorption spectrum and X-ray photoelectron spectroscopy (XPS) reveal that GOSs and GORs were photoreduced with TiO2-NS under ultraviolet irradiation. The as-prepared TiO2 nanosheets/graphene sheets (TS-GNSs) or ribbons (TS-GNRs) display drastically quenching of photoluminescence (PL) intensity and lower electron impedance, and TS-GNSs show better results than TS-GNRs. It is due to the excellent mobility of charge carriers and large surface area with graphene, which facilitate the separation of electron–hole pairs. Thus, TS-GNSs and TS-GNRs exhibit prominent photocatalytic activity under ultraviolet irradiation. The degradation efficiency of RhB is nearly 80% for TS-GNRs and 100% for TS-GNSs within 25 min. The lower degradation efficiency of TS-GNRs is due to the lower charge mobility of GNRs, which demonstrates that the excellent charge mobility of graphene plays a crucial role in composites for photodegradation.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (309 K)Download as PowerPoint slide
