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 Cu 2 O/ Cu 2 (PO 4 )(OH) heterojunction nanocomposite with the outstanding photocatalytic degradation performance of ciprofloxacin (CP) antibiotic under direct sunlight irradiation. The hierarchical cactus-like Cu 2 O/Cu 2 (PO 4 )(OH) structures were prepared by a simple reflux route at 100 °C for 3 h. When Cu 2 O/Cu 2 (PO 4 )(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 Cu 2 O (48%) and Cu 2 (PO 4 )(OH) (74%). The excellent photocatalytic activity of the Cu 2 O/Cu 2 (PO 4 )(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 Cu 2 O/Cu 2 (PO 4 )(OH) nanocomposites.

Research Progress on Cu2O‐based Type‐II Heterojunction Photocatalysts for Photocatalytic Removal of Antibiotics

“… Schematic design of the synthesis of the hierarchical Cu 2 O/Cu 2 (PO 4 )(OH) nanocomposite by the refluxing method and its photocatalytic degradation performance (a). Reprinted with permission from ref [143] . Copyright 2020 American Chemical Society.…”

“…The unique constructure can enhance the charges migration. Beshear et al [143] . synthesized hierarchical cactus‐like Cu 2 O/Cu 2 (OH)PO 4 composite by a simple refluxing method, as shown in Figure 12(a), which has enhanced photocatalysis.…”

“…Compared Reprinted with permission from ref. [143] Copyright 2020 American Chemical Society. Charge transfer on irradiation (b) Internal reflection from silicate glass onto junction (c) Possible Z-scheme transfer in silicate glass matrix@Cu 2 O/Cu 2 V 2 O 7 photocatalyst (d).…”

“…The unique constructure can enhance the charges migration. Beshear et al [143] synthesized hierarchical cactus-like Cu 2 O/Cu 2 (OH)PO 4 composite by a simple refluxing method, as shown in Figure 12(a), which has enhanced photocatalysis. In the composite system, Cu 2 O nanoparticles have significant light absorption, and the uniformly stratified Cu 2 O/Cu 2 (PO 4 )(OH) structure can promote surface contact with antibiotic molecules and increase more active sites.…”

Photocatalytic Removal of Ciprofloxacin in Water by Novel Sandwich-like CuFe2O4 on rGO/Halloysite Material: Insights into Kinetics and Intermediate Reactive Radicals

“…Therefore, various strategies have been proposed to overcome these drawbacks, such as doping with metals or non-metals, coupling with other semiconductors, modifying with noble metal nanoparticles, and designing novel nanostructures [11,12]. Several photocatalysts for CIP treatment have been researched and produced, including ZnO-based photocatalysts [13], Ag-TiO 2 photocatalysts [14], and Cu 2 O photocatalysts [15,16]. Since the photo-Fenton effect and the existence of a metal combination are present, CuFe 2 O 4 is a new material that has a small band gap energy and exhibits high and consistent activity during reactions [17,18].…”