Magnetically Separable Iron Oxide-Based Nanocomposite Photocatalytic Materials for Environmental Remediation

The preparation of magnetically separable iron oxide-based nanostructured semiconductor composite photocatalysts and their application in environmental remediation are elucidated in detail. Magnetic nanocomposite photocatalysts can be effortlessly separated from a fluid using an external magnetic field. Therefore, catalyst recovery and economic reuse of the catalyst can be achieved easily. This magnetically separable semiconductor nanocomposite photocatalyst technique is more worthwhile for environmental engineering applications. ‘Nanocomposite photocatalyst’ is the term for a photocatalyst that has dimensions in nanometers. Nanocomposite magnetic photocatalysts have unique intrinsic properties, such as high surface to volume ratio, magnetic separation, abundant active sites, better light absorbance, and enhanced charge carrier separation. In this regard, iron oxide is an irresistible candidate. Iron oxide-based magnetic materials are classified as hematite, maghemite, magnetite, and spinel ferrites. Magnetic semiconductor nanophotocatalysts are classified into three groups: (i) a magnetic core coated semiconductor cell, (ii) a magnetic core coated semiconductor cell with an interlayer, and (iii) a magnetic core coated semiconductor cell with a doped semiconductor. Each category has its own merit and demerits which are described in a brief manner in this chapter. Further, currently emerging two-dimensional magnetic nanocomposites photocatalyst are also discussed. Moreover, iron oxide-based semiconductor nanophotocatalysts are employed to remove range of different organic contaminants, such as synthetic dyes, heavy metals, toxic chemical compounds (phenol, sulfamethazine), and pharmaceutical waste. The effects of iron oxide-based photocatalysts on each pollutant are discussed briefly at the end of the chapter.