Photocatalytic activity of ɑ-Fe2O3 synthesized by sol-gel method using cellulose nanocrystals as sacrificial template

Abstract

In this study, hematite (a-Fe2O3) was prepared based on the sol–gel method using cellulose nanocrystals (CNCs) as sacrificial template, and its performance on degradation of methylene blue from aqueous solution under sunlight irradiation was investigated. CNCs were synthesized from Nypa fruticans trunk (NFT) biomass via formic /peroxyformic acid process treatment and acid hydrolysis at atmospheric pressure. Images generated by transmission electron microscopy (TEM) showed that CNCs were rod-like in morphology, average diameter and length of 10 nm and 410 nm, respectively. The obtained CNCs were used as a template to prepare hematite (a-Fe2O3) nanostructures through sol-gel method. The samples were characterized by Field Emission Scanning Electron Microscope (FESEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Their surface area was analyzed by the N2 adsorption-desorption curve. The crystallite size of a-Fe2O3 prepared with CNCs and without CNCs, calculated from the XRD data by the Debye–Scherrer equation, were about 17.69 nm and 19.35 nm, respectively. The nitrogen adsorption characterization confirmed that the prepared a-Fe2O3 possessed the mesoporous structure, and its specific surface area was 90.9 m2g-1. The mesoporous a-Fe2O3 prepared with CNCs as template exhibited a significantly improved photocatalytic activity than that of the sample prepared without CNCs during the MB photocatalytic degradation process.