Facile Synthesis and Photocatalytic Property of Titania/Carbon Composite Hollow Microspheres with Bimodal Mesoporous Shells

Guohong Wang,Jun Zhang,Lin Xu,Bei Cheng,Tingting Yin

doi:10.1155/2012/976389

Abstract

Titania/carbon composite hollow microspheres with bimodal mesoporous shells are one-pot fabricated by hydrothermal treatment of the acidic (NH4)2TiF6aqueous solution in the presence of glucose at180∘C for 24 h and then calcined at450∘C. The as-prepared samples were characterized by XRD, SEM, TEM, HRTEM, UV-visible spectroscopy, and nitrogen adsorption-desorption isotherms. The photocatalytic activity of the as-prepared samples was evaluated by daylight-induced photocatalytic decolorization of methyl orange aqueous solution at ambient temperature. The effects of calcination time on the morphology, phase structure, crystallite size, specific surface area, pore structures, and photocatalytic activity of the microspheres were investigated. The results indicated that the as-obtained TiO2/C composite hollow spheres generally exhibit bimodal mesopore size distribution with their peak intra-aggregated mesopore size in the range of 2.3–4.5 nm and peak interaggregated mesopore size in the range of 5.7–12.7 nm, depending on specific calcination time. The daylight-induced photoactivity of as-obtained hollow TiO2/C microspheres generally exceeds that of Degussa P25. The influences of calcination time on the photoactivity are discussed in terms of carbon content, phase structures, and pore structures.

Highlights

Photocatalytic degradation of organic compounds for the purpose of purifying water or wastewater from industries and households has attracted great attention in the past decade [1,2,3,4,5,6,7]
Titania/carbon composite hollow microspheres with bimodal mesoporous shells are one-pot fabricated by hydrothermal treatment of the acidic (NH4)2TiF6 aqueous solution in the presence of glucose at 180◦C for 24 h and calcined at 450◦C
The results indicated that the as-obtained TiO2/C composite hollow spheres generally exhibit bimodal mesopore size distribution with their peak intra-aggregated mesopore size in the range of 2.3–4.5 nm and peak interaggregated mesopore size in the range of 5.7– 12.7 nm, depending on specific calcination time

Summary

Introduction

Photocatalytic degradation of organic compounds for the purpose of purifying water or wastewater from industries and households has attracted great attention in the past decade [1,2,3,4,5,6,7]. The fabrication of TiO2 hollow structures attracts special attention due to their low density, high surface area, good surface permeability and larger light-harvesting capacities [9]. Various studies have demonstrated that titanium/carbon composite photocatalysts can result in a synergistic effect of both adsorption and photocatalysis and can dramatically improve the daylight-induced photocatalytic activity of titania for different modal organic components [30,31,32,33,34,35,36,37]. Preparation of well-crystallized titanium/carbon composite hollow microspheres with high daylightinduced photocatalytic activity keeps still a great challenge. Titanium/carbon composite hollow microspheres with bimodal mesoporous shell are one-pot fabricated according to the method reported by Titirici and coworkers [29] and their visible light photocatalytic activity is investigated

Experimental Section

Results and Discussion

Conclusions