Mn doping accelerates regeneration of Fe2+ in FeOOH and promotes efficient H2O2 activation for degradation of As(III)

In this study, a carbonized aerogel (CA) decorated with Mn-FeOOH hybrid nanoparticles was prepared and has been used as a better heterogeneous photo-Fenton catalyst. Mn doping accelerated the regeneration of Fe 2+ and promoted the decomposition of H 2 O 2 while producing many hydroxyl radicals (·OH), which solved the mass transfer problem in the traditional heterogeneous Fenton system. The amount of·OH in the Mn-FeOOH@CA/H 2 O 2 system within 40 min was 2.4 times higher than that in the FeOOH@CA/H 2 O 2 system, which further indicates that·OH was the main active species. High-porosity CA has been designed as an electron transport channel. During photocatalysis , electron transfer occurred between the Mn-FeOOH composite material and CA. The Fe 2+ could be used as reaction sites to promote the activation of H 2 O 2 on the surface of 1-Mn/FeOOH, and achieved 100 % As(III) degradation efficiency within 25 min. The catalyst maintained more than 80 % of its original oxidation capacity after five cycles of experiments, which indicates that it has good durability. This work is expected to provide rational design of heterometallic doped materials with oxygen vacancies to treat arsenic pollution.