Nanoporous core–shell Cu@Cu2O nanocomposites with superior photocatalytic properties towards the degradation of methyl orange

Abstract

We present a facile two-step strategy to fabricate a novel nanoporous core–shell Cu@Cu2O nanocomposite photocatalyst. The photocatalyst was synthesized via the combination of dealloying of the as-milled Al66.7Cu33.3 (at.%) precursor powders in alkaline media with subsequent surface oxidation in air. The microstructure of the as-prepared photocatalyst has been characterized by X-ray diffraction (XRD), a field-emission scanning electron microscope (FESEM) and a transmission electron microscope (TEM). The results show that the as-prepared photocatalyst exhibits an open, bicontinuous interpenetrating ligament (ca. 30 nm)–channel (ca. 15 nm) structure, and is comprised of Cu (core) and Cu2O (shell) phases. Methyl orange (MO) was used as the model pollutant, and photodegradation experiments were monitored by UV-vis spectrophotometry. The nanoporous core–shell Cu@Cu2O photocatalyst shows excellent photocatalytic activity towards the degradation of MO under sunlight. The MO degradation rate can reach as high as 8.04 mg min−1 gcat−1. In addition, the influence of additive amounts of photocatalyst and initial concentrations of MO on the photodegradation process has been investigated. The photodegradation mechanism of the as-prepared photocatalyst has also been discussed.