High Efficient Visible-Light Photocatalytic Performance of Cu/ZnO/rGO Nanocomposite for Decomposing of Aqueous Ammonia and Treatment of Domestic Wastewater

Abstract

Photocatalytic removal of ammonium-nitrogen (NH4+-N) from water using solar energy is an approach of high interest and applicability due to the convenience in application. ZnO has a great potential in photocatalytic decomposition of NH4+-N and conversion of this nutrient to under visible light irradiations. However the applicability of pristine ZnO though is limited due to its reduced capacity to utilize light from natural light. Herein, we report a two-step ZnO-modified strategy (Cu-doped ZnO nanoparticles, immobilized on reduced graphene oxide (rGO) sheets) for the promotion of photocatalytic degradation of NH4+-N under visible light. UV-Vis spectra showed that the Cu/ZnO/rGO can be highly efficient in the utilization of photons from the visible region. Hence, Cu/ZnO/rGO managed to demonstrate adequate photocatalytic activity and effective NH4+-N removal from water under visible light compared to single ZnO. Specifically, up to 83.1% of NH4+-N (initial concentration 50 mg·L−1, catalyst dosage 2 g·L−1, pH 10) was removed within 2 h retention time under Xe lamp irradiation. From the catalysis, the major by-product was N2. The high ammonia degradation efficiency from the ZnO/Cu/rGO is attributed to the improvement of the reactive oxygen species (ROSs) production efficiency and the further activation of the interfacial catalytic sites. This study also demonstrated that such nanocomposite is a recyclable agent. Its NH4+-N removal capacity remained effective even after five batch cycles. In addition, Cu/ZnO/rGO was applied to treat real domestic wastewater, and it was found that chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) removal efficiencies can reach 84.3, 80.7, and 90.3%, respectively. Thus, Cu/ZnO/rGO in the presence of solar light can be a promising photocatalyst in the field of wastewater treatment.

Cu-Doped ZnO Nanoparticles for Non-Enzymatic Glucose Sensing

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“…Despite quite similar radii for Cu 2+ and Zn 2+ cations (Cu 2+ : 0.73 Å, Zn 2+ : 0.74 Å) [ 18 ], relatively low values of Cu content can be incorporated in the ZnO wurtzite structure, without the phases demixing. In the case of Cu-doped ZnO nanorods synthesized using an ice-bath-assisted sonochemical technique, Othman et al [ 21 ] reported a single phase (wurtzite) up to a doping content of 4% Cu.…”

A Novel α‑Fe2O3/TiO2 heterostructured nanocomposite with Enhanced Visible-light Photocatalytic Performance for Degradation of Organic Pollutant

“…To meet the shortage in water supply worldwide and improving the environmental pollution, the elimination of several impurities from adequate water has major pervasive problem worldwide with widespread concerned. Nowadays the rapid industrialization of modern society exclusively in the developing countries, organic dyes are widely used in paper, leather, textile, pigment, cosmetic, food, and drug manufacturing [1][2][3]. Besides, the industrial and sanitary sewage comprises dyes cause water contamination as serious health problems and they are hazardous effects toward aquatic organisms, plants, humans, animals and aquatic ecosystem.…”

Enhancing the Photocatalytic Activity of SnO2-TiO2 and ZnO-TiO2 Tandem Structures Toward Indoor Air Decontamination

“…Different mono-component metal oxide photocatalyst such as ZnO (He et al, 2018;Smazna et al, 2019), TiO 2 (Andronic et al, 2014;Castellanos et al, 2020), WO 3 (Yang et al, 2018;Zhao et al, 2020) or SnO 2 (Enesca et al, 2012a;Patil et al, 2018) were widely used for wastewater and air pollutant removal. Although efficient, these materials have limitations in terms of charge carrier recombination, absorption range, and photoactive crystalline structure.…”