Direct polymerization of polyheptazine in the interlamelar spaces of titanate nanotubes enhances visible-light response

Author(s)

Rodrigues, Barbara S. ; Almeida, Vinicius A. ; Claudino, Caroline H. ; Ponce-de-Leon, Carlos ; Bavykin, Dmitry V. ; Souza, Juliana S.

• Document type: Journal article
• Source: JOURNAL OF NANOSTRUCTURE IN CHEMISTRY; v. 10, n. 4, p. 14-pg., 2020-10-07.

Abstract

A hybrid organic-inorganic catalyst of polyheptazine and TiO2 nanotubes was obtained by polymerization of polyheptazine directly on the surface of layered titanate nanotubes (TiNT) at 400 degrees C; leading to a phase transition from TiNT to TiO2 anatase. This method induces the polymerization in-between the layers of TiNTs, in contrast to what happens on commercial TiO2 nanoparticles (P25), for which polymer adsorption occurs only onto the outer surface. As a result, the hybrid materials exhibit enhanced physical-chemical properties, resulting in improved photocatalytic response; the methylene blue degradation was 1.28-times higher using the hybrid polyheptazine-TiO2 nanotubes as a photocatalyst, in comparison to the use of polyheptazine-P25. Besides, polyheptazine-TiO(2)nanotubes show higher photo-electrocatalytic activity than TiNTs, whereas polyheptazine-P25 exhibits lower activity than P25. The lower band-gap energies, zeta potentials and higher surface area make the polyheptazine-TiO2 nanotubes more efficient photocatalysts under visible light in comparison to P25-based nanoparticles. [GRAPHICS] . (AU)

• FAPESP's process: 19/26010-9 - Photoactive devices based on heterojunctions of bismuth vanadate and tungsten oxide over graphene
• Grantee: Bárbara Scola Rodrigues
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 17/11395-7 - Microwave-assisted synthesis of metal oxides semiconductors heterojunctions with photocatalytic applications
• Grantee: Juliana dos Santos de Souza Silva
• Support Opportunities: Regular Research Grants