The effect of humic acid binding to magnetite nanoparticles on the photogeneration of reactive oxygen species

LUCIANO CARLOS; MARIANO CIPOLLONE; DELIA B. SORIA; M. SERGIO MORENO; PETER R. OGILBY; FERNANDO S. GARCÍA EINSCHLAG; DANIEL O. MARTIRE

SEPARATION AND PURIFICATION TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 vol. 91 p. 23 - 29

1383-5866

The goal of this study was to investigate how the binding of humic acids (HA) to magnetite nanoparticles affects the ability of the HA to generate reactive oxygen species (ROS) upon irradiation. To this end, magnetite nanoparticles coated with two different HA were prepared by the co precipitation method. These particles were characterized by several techniques. The nanoparticle sensitized quantum yield of singlet oxygen generation at lambda exc = 400 nm and the quantum efficiencies (lambda exc = 300?550 nm) of hydroxyl radical and hydrogen peroxide generation were measured and compared to the corresponding quantum yields obtained from solutions of the free HA. Despite being bonded to the magnetite nanoparticles, the HA are still able to generate ROS upon irradiation. As with free HA, the yields of ROS generation by the magnetite-bonded HA depend on the particular HA involved.