Graphene@Metal Sulfide/Oxide Nanocomposites as Novel Photo‐Fenton‐like Catalysts for 4‐Nitrophenol Degradation
Renata Matos, Marta Nunes, Iwona Kuźniarska‐Biernacka, Mariana Rocha, Alexandra Guedes, Ana C. Estrada, Joana L. Lopes, Tito Trindade, Cristina Freire
Abstract
Abstract Herein, S‐doped graphene flakes‐based composites with Fe 3 O 4 and/or CuS nanoparticles (NPs) are reported as photo‐Fenton catalysts for the 4‐nitrophenol (4‐NP) degradation. The S‐doped graphene flakes (S‐GF) were prepared using a thermal treatment approach, and the nanocomposites by the in situ growth of Fe 3 O 4 and/or CuS onto the S‐GF scaffold. The characterization methods confirmed the formation of two‐ and three‐components nanocomposites. The Fe 3 O 4 NPs presented a cubic inverse spinel structure and the CuS phases a covellite structure, both with smaller crystallite sizes in the nanocomposites. The new nanocomposites showed higher ability to catalyze the photo‐Fenton 4‐NP degradation than the individual components. The S‐GF@CuS−Fe 3 O 4 nanocomposite exhibited the best catalytic activity: 95.2 % of 4‐NP degradation, a kinetic of pseudo‐first order ( k =0.016 min −1 ), high photo‐Fenton catalytic stability and catalyst's composition/structure preservation. The CuS NPs showed an important role in the photo‐Fenton‐like catalytic activity improvement.