Rectorite-supported nano-Fe3O4 composite materials as catalyst for P-chlorophenol degradation: Preparation, characterization, and mechanism

Clay minerals, as abundant natural resources, are among the most suitable supporting materials for nano metal. In this manuscript, new Fe3O4 nanoparticle/rectorite (Fe3O4/rectorite) catalysts are developed via in-situ precipitation oxidation reaction. Various physicochemical characterizations of Fe3O4/rectorite show that Fe3O4 nanoparticles (nano-Fe3O4) with an average particle diameter of approximately 10-20 nm are effectively loaded on the surface of acid leached rectorite (Al-rectorite) and have low coaggregation and improved dispersion. Moreover, the catalytic activity of Fe3O4/rectorite on degradation of P-chlorophenol by heterogeneous Fenton method is studied. Results of degradation experiments show that Fe3O4/rectorite has higher degradation efficiency of P-chlorophenol than bare nano-Fe3O4. Regeneration studies also show that Fe3O4/rectorite maintains 100% of its maximum P-chlorophenol degradation capacity after seven consecutive cycles. Fe3O4/rectorite can be easily separated by magnetic separation, and thus has good stability and reusability. The degradation mechanism of Fe3O4/rectorite is adsorption coupled with a Fenton-like reaction, which accounts for P-chlorophenol degradation of up to 625 mg/g. This work demonstrates a new composite material for the effective remediation of refractory organic compounds from wastewater.