Photocatalytic activity of Cu₂O/ZnO nanocomposite for the decomposition of methyl orange under visible light irradiation

Abstract

ZnO is modified by Cu2O by the process of precipitation and calcination. X-ray diffraction has shown that Cu2O/ZnO catalysts are made of highly purified cubic Cu2O and hexagonal ZnO. Scanning electron microscopy and transmission electron microscopy have shown that ZnO adhered to the surface of Cu2O. Due to the doping of Cu2O, the absorption range of the Cu2O/ZnO catalyst is shifted from the ultraviolet to the visible region due to diffuse reflection. X-ray photoelectron spectroscopy and photoluminescence spectra have confirmed that there is a substantial interaction between the two phases of the resultant catalyst. The degradation efficiency of Cu2O/ZnO on methyl orange solution is obviously enhanced compared to Cu2O and ZnO. The maximum degradation efficiency is 98%. The degradation efficiency is affected by the pH of the solution and initial concentration. After three rounds of recycling, the degradation rate is almost same. This shows a consistent performance of Cu2O/ZnO. The increase in catalytic ability is related to the lattice interaction caused by the doping of Cu2O.

Copper sulfide and zinc oxide hybrid nanocomposite for wastewater decontamination of pharmaceuticals and pesticides

“…From the CuS QDs @ ZnO XRD pattern, as the (107) and (103) planes of CuS appeared at 47.9° and 31.8°, respectively, and the (102) and (002) planes of ZnO appeared at 47.8° and 31.7°, it is observed that the CuS peaks at 31.78° and 47.64° are merged with ZNR peaks with a slight displacement. The small displacement between the (107) plane of CuS and the (102) plane of ZnO can confirmed the existence of lattice interaction, implying the formation of p-n heterojunctions 50 , 51 .…”

Synthesis and Characterization of Broccoli-like Ag/Cu2O Nanostructures on ZnO Nanowires Using the Plasma–Liquid Interaction Method

“…Therefore, the exploitation of a ZnO/Cu 2 O heterojunction is expected to slow down the charge carrier recombination rate-since there exists an irreversible electric field at the p-n junction of the ZnO/Cu 2 O system-and expand the absorption spectrum toward the visible light range, as shown in previous articles [8][9][10][11]. Furthermore, the concordance between the energy level and the electronic structure in the ZnO and Cu 2 O forms a superior catalytic p-n system compared with other p-n systems [8][9][10][11][12][13]. On the other hand, the formation of a Schottky barrier at the precious metal-semiconductor interface can efficiently prevent the recombination of electron-hole pairs [14][15][16].…”

Hydrothermal fabrication of p‐Cu2O−n‐ZnO films and their properties for photodegradation and ultraviolet sensors

“…Wang et al. fabricated p‐Cu 2 O−n‐ZnO nanoparticle heterojunctions through precipitation and calcination methods, 40 and their samples exhibited superior degradation efficiency of MO compared with Cu 2 O and ZnO alone under visible‐light irradiation. Hsiao et al.…”

“…7 The sample exhibited excellent photodegradation of methyl orange (MO) under visible-light irradiation. Wang et al fabricated p-Cu 2 O−n-ZnO nanoparticle heterojunctions through precipitation and calcination methods, 40 and their samples exhibited superior degradation efficiency of MO compared with Cu 2 O and ZnO alone under visible-light irradiation. Hsiao et al reported the synthesis of ZnO−Cu 2 O on Si nanowires (SiNWs) (supporting skeleton) using all-solution-based approaches.…”