title: The flux growth of single-crystalline CoTiO3polyhedral particles and improved visible-light photocatalytic activity of heterostructured CoTiO3/g-C3N4composites.
abstract: Highly crystalline and idiomorphic CoTiO3single crystals with a well-defined polyhedral morphology were grown successfully for the first time by a facile flux method. Herein, the effects of the molten salt type and cobalt precursor on the phase composition, crystallization habit and morphology of the CoTiO3products were also investigated. Importantly, using the flux-grown CoTiO3crystal as the visible-light sensitizer due to its narrow band gap to couple with graphitic carbon nitride (g-C3N4) by a direct in situ thermal induced polycondensation route, novel CoTiO3/g-C3N4composite photocatalysts were obtained. The as-synthesized samples were systematically characterized by XRD, EDS, SEM, TEM, SAED, HRTEM, FT-IR, XPS, DRS and PL techniques. The results revealed that CoTiO3polyhedral crystals were closely combined with g-C3N4nanosheets leading to the formation of a heterojunction structure at the interface between CoTiO3and g-C3N4. Photocatalytic evaluation showed that the heterostructured CoTiO3/g-C3N4composite exhibited much higher photocatalytic activity for the degradation of methyl orange under visible light irradiation than that of individual CoTiO3and g-C3N4, which could be mainly ascribed to the synergistic effect between CoTiO3and g-C3N4, including the enhanced visible-light harvesting ability and more efficient separation and longer lifetime of photogenerated charge carriers. Furthermore, the composite photocatalyst showed an excellent stability and reusability during four successive cycles. Finally, a possible mechanism responsible for the charge separation and improved photocatalytic activity was proposed.
authors.affiliation: School of Mechanical and Power Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China. bingli@ecust.edu.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Guo
authors.forename: Leping
authors.initials: L
authors.lastname: Wang
authors.forename: Bing
authors.initials: B
authors.lastname: Li