Facile One-Pot In Situ Synthesis and Characterization of a Cu2O/ Cu2(PO4)(OH) Binary Heterojunction Nanocomposite for the Efficient Photocatalytic Degradation of Ciprofloxacin from Aqueous Solution under Direct Sunlight Irradiation

Abstract

Antibiotic-containing wastewater as a dangerous factor for human health must be effectively removed from the environment. In this work, we fabricated a novel full-spectrum solar-driven Cu2O/Cu2(PO4)(OH) heterojunction nanocomposite with the outstanding photocatalytic degradation performance of ciprofloxacin (CP) antibiotic under direct sunlight irradiation. The hierarchical cactus-like Cu2O/Cu2(PO4)(OH) structures were prepared by a simple reflux route at 100 °C for 3 h. When Cu2O/Cu2(PO4)(OH) photocatalysts with a band gap energy of 2.26 eV were applied for the degradation of CP antibiotic, a high photodegradation efficiency (∼98%) was obtained after 2 h of sunlight irradiation, which was higher than individual Cu2O (48%) and Cu2(PO4)(OH) (74%). The excellent photocatalytic activity of the Cu2O/Cu2(PO4)(OH) photocatalyst can be mainly attributed to the unique hierarchical morphology, promoted visible-near infrared absorption, high separation, and low recombination rate of electron−hole pairs originated from the as-formed heterojunction structures. In addition, we suggested an advisable photocatalytic degradation mechanism based on the radical trapping trial, which disclosed that the hydroxyl (•OH) and hole (h+) species have a fundamental responsibility for the photocatalytic degradation of CP over Cu2O/Cu2(PO4)(OH) nanocomposites.