Synthesis of Mesoporous TiO2-B Nanobelts with Highly Crystalized Walls toward Efficient H2 Evolution.

Li Li,Kim Kim,Lai Lai,Hou Hou,Alzahrani Alzahrani,Zheng Zheng,Ide Ide,Alghamidi Alghamidi,Alshehri Alshehri,Lin Lin,Cao Cao,Bando Bando,Malgras Malgras,Yamauchi Yamauchi

doi:10.3390/nano9070919

Abstract

Mesoporous TiO2 is attracting increasing interest due to properties suiting a broad range of photocatalytic applications. Here we report the facile synthesis of mesoporous crystalline TiO2-B nanobelts possessing a surface area as high as 80.9 m2 g−1 and uniformly-sized pores of 6–8 nm. Firstly, P25 powders are dissolved in NaOH solution under hydrothermal conditions, forming sodium titanate (Na2Ti3O7) intermediate precursor phase. Then, H2Ti3O7 is successfully obtained by ion exchange through acid washing from Na2Ti3O7 via an alkaline hydrothermal treatment. After calcination at 450 °C, the H2Ti3O7 is converted to a TiO2-B phase. At 600 °C, another anatase phase coexists with TiO2-B, which completely converts into anatase when annealed at 750 °C. Mesoporous TiO2-B nanobelts obtained after annealing at 450 °C are uniform with up to a few micrometers in length, 50–120 nm in width, and 5–15 nm in thickness. The resulting mesoporous TiO2-B nanobelts exhibit efficient H2 evolution capability, which is almost three times that of anatase TiO2 nanobelts.

Highlights

Mesoporous metal oxides are used in a wide range applications such as energy conversion and storage [1,2], catalysis [3,4], gas sensors [5], etc., because of their high specific surface area and mesoporous networks
Mesoporous TiO2 with regular and interpenetrated porous networks have been demonstrated as an effective photocatalyst due to its low cost, environmental friendliness, good physical and chemical stability, large surface area, pore volume and tunable porous structure [6,7,8]
Many efforts have been devoted to developing diverse techniques towards the synthesis of mesoporous TiO2 [9,10,11,12,13,14,15,16,17,18]

Summary

Introduction

Mesoporous metal oxides are used in a wide range applications such as energy conversion and storage [1,2], catalysis [3,4], gas sensors [5], etc., because of their high specific surface area and mesoporous networks. Huang et al demonstrated the use of graphene as a current collector to construct hybrid graphene/TiO2-B nanostructures to optimize the performance [27]. Such a hybrid mesoporous architecture can realize fast electron transport and acceleration of diffusion of lithium ions. 1D nanorods or nanotubes have gained attention due to enhanced charge mobility and strong light absorption, they suffer from lower surface area and poor crystallinity. It is, highly desirable to fabricate highly crystalline TiO2-B nanostructures with enhanced surface area for photocatalytic applications

Methods

Results

Conclusion