Facile preparation of exposed {001} facet TiO2 nanobelts coated by monolayer carbon and its high-performance photocatalytic activity

The photocatalytic property of TiO2-based nanomaterials can be markedly enhanced by hybridizing conjugated materials at the surface. In this paper, we first utilized a silane coupling agent as carbon source and grafting reagent to prepare a graphite-like carbon coating on the surface of {001} crystal facets that were exposed on TiO2 nanobelts. The thickness of this carbon layer could be controlled to a thickness of a few molecules by adjusting the addition of silane. Due to the synergistic effects between the monolayer carbon coating (similar to 1 nm) and the exposed {001} crystal facets, the as-prepared TiO2 nanobelts enhanced the photocatalytic activity by approximately 2.5 times that of pure TiO2 (Degussa, P-25), to photodegrade methylene blue under UV light. Additionally, the photodegradation of rhodamine B (RHB) was better (approximately 2.1 times) than that of P-25. Further, we discuss the proper mechanism of the enhanced performance, which is attributed to the faster transfer of photogenerated electrons by d-pi interaction and the decreased possibility of recombination of e(-)/h(+)pairs.