CdSe cluster-modified biogenic α-FeOOH based on macroporous biochar for Fenton-like reaction of As(III)

In this study, CdSe cluster-modified biogenic α − FeOOH based on macroporous biochar was constructed from rhizosphere iron plaque via pyrolysis. An ultrahigh H2O2 production rate of 655.75 μmol/L was achieved by the photocatalysis-self-Fenton system within 30 min under visible light irradiation. α-FeOOH, with abundant iron ions, can directly activate H2O2 to produce abundant ⋅OH radicals. It was found that As(III) (10 mg/L) could be completely degraded within 20 min. Electron spin resonance spectroscopy (ESR) and density functional theory (DFT) revealed that a suitable energy band structure was achieved by the introduction of CdSe clusters; thus, O2 was mainly reduced to H2O2 through a two-electron reduction route in the reaction system. The photogenerated electrons promoted the conversion of Fe(III)/Fe(II) by reacting with Fe(III) in α-FeOOH. The presence of H2O2 and Fe2+ in this system accelerates the oxidation of As(III) by a Fenton-like reaction.