TiO2 Nanocrystals Grown on Graphene as Advanced Photocatalytic Hybrid Materials

TL;DR

This paper reports a novel method for growing TiO2 nanocrystals directly on graphene oxide sheets, resulting in a hybrid material with enhanced photocatalytic activity and potential for energy storage applications.

Contribution

A new two-step hydrothermal method for controlled growth of TiO2 nanocrystals on graphene oxide, improving hybrid material quality and performance.

Findings

Demonstrated 3-fold increase in photocatalytic degradation of rhodamine B

Achieved strong coupling between TiO2 and graphene oxide

Provided a scalable method for hybrid material synthesis

Abstract

Graphene/TiO2 nanocrystals hybrid is successfully prepared by directly growing TiO2 nanocrystals on graphene oxide (GO) sheets. The direct growth of nanocrystals on GO sheets was achieved by a two-step method, in which TiO2 was coated on GO sheets by hydrolysis first and crystallized into anatase nanocrystals by hydrothermal treatment in second step. Slow hydrolysis reaction through the use of EtOH/H2O mixed solvents and addition of H2SO4 allows the selectively growing TiO2 on GO and suppressing free growth in solution. The method offers easy access to the GO/TiO2 nanocrystals hybrid with well controlled coating and strong interactions between TiO2 and the underlying GO sheets. The strong coupling could lead to advanced hybrid materials for various applications including photocatalysis. The prepared graphene/TiO2 nanocrystals hybrid has demonstrated superior photocatalytic activity in degradation of rhodamine B over other TiO2 materials, showing an impressive 3-fold photocatalytic enhancement over P25. It is expected that the hybrid material could also be promising for various other applications including lithium ion battery where strong electrical coupling to TiO2 nanoparticles is essential.