Enhanced photocatalytic degradation of sulfamethoxazole by stable hierarchical Fe2O3/Co3O4 heterojunction on nickel foam

Abstract

A facile approach was successfully employed to prepare Fe2O3/Co3O4 nanosheet arrays on nickel foams (Fe2O3/Co3O4@NF), which owned such advantages as narrow band gap energies and high separation rate of photoexcited electron-hole pairs. The combination of Fe2O3 and Co3O4 dramatically enhanced the photocatalytic activity towards sulfamethoxazole (SMZ) degradation, with the highest catalytic efficiency of k = 0.0538 min−1, which was much higher than that of Fe2O3@NF (0.0098 min−1) and Co3O4@NF (0.0094 min−1). The introduction of Ni foam could not only act as the support to anchor photocatalyst, but also work as the electron mediator to promote the transition of electron-hole pairs. Reactive species trapping experiments combined with electron paramagnetic resonance analysis confirmed •O2− was primarily responsible for SMZ degradation. Furthermore, Fe2O3/Co3O4@NF was effective and almost unaffected by inorganic cations and anions in aqueous solution. This study could provide a facile and promising path for the construction of self-supported metal oxide-based heterojunction with high efficiency and strong stability.