Photocatalytic Properties of Core-Shell Structured Wool-TiO2 Hybrid Composite Powders

Haoshuai Gu,Hui Zhang,Ningtao Mao,Hailiang Wu,Limeng Yang,Yani Guo,Xinyue Zhang

doi:10.3390/catal11010012

Abstract

In this study, a special core–shell structured wool-TiO2 (WT) hybrid composite powder also having TiO2 nanoparticles incorporated inside cortical cells was reported. The wool pallets were pulverized from wool fibers using vibration-assisted ball milling technique and the WT powders having mesopores and macropores were produced in hydrothermal process. Experimental results indicated that the infiltrated TiO2 nanoparticles were amorphous structure, while the coated TiO2 nanoparticles were anatase phase structure. The crystallized TiO2 nanoparticles were grafted with wool pallets by the N−Ti4+/S−Ti4+/O−Ti4+ bonds. The BET surface area was measured as 153.5 m2/g and the particle sizes were in the 600–3600 nm and 4000–6500 nm ranges. The main reactive radical species of the WT powders were holes, and •O2−, 1O2, and •OH were also involved in the photodegradation of MB dye under visible light irradiation. The experimental parameters for photodegradation of MB dye solution were optimized as follows: 0.25 g/L of WT powders was added in 40 mL of 3 mg/L MB dye solution containing 50 mL/L H2O2, which resulted in the increases of COD value of degraded MB dye solution up to 916.9 mg/L at 120 min. The WT powders could be used for repeatedly photodegradation of both anionic and cationic dyes.

Highlights

Wool as abundant natural protein fibers has been applied in a wide range of fields especially textile industry owing to its exceptional physical and chemical properties, such as good texture, moderate strength, high elasticity, strong water absorption, and easy dye-ability [1]
The microscopic morphologies of the grinded wool pallets before and after treatment with tetrabutyl titanate (TBT) under hydrothermal condition were observed on a field emission scanning electron microscopy (FESEM) instrument
These grinded small wool particles were piled up to form into the wool pallets having larger grain sizes, while still having both increased specific surface area and exposed more active groups [17]

Summary

Introduction

Wool as abundant natural protein fibers has been applied in a wide range of fields especially textile industry owing to its exceptional physical and chemical properties, such as good texture, moderate strength, high elasticity, strong water absorption, and easy dye-ability [1]. Wool fibers can be biodegradable in landfill with certain bacteria in the environment. It is worthwhile noting that wool fibers have a complex structure containing amorphous cortex and non-crystalline cuticle layer, which are composed of 18 different amino acids [2]. To make full use of the high value-added proteinaceous fibers, besides various physical and chemical routes [3], an environmentally benign milling technique [4] has recently received considerable attention because the increased surface area of wool powders can licenses/by/4.0/)

Methods

Results

Conclusion