Multifunctional and smart Er2O3-ZnO nanocomposites for electronic ceramic varistors and visible light degradation of wastewater treatment.

Thekrayat Alabdulaal,Hamed Algarni,Mohamed Abdel-Wahab,Saqib Rafique,Heba Zahran,Mai Hussien,Vanga Ganesh,Manal Alshadidi,Ibrahim Yahia,Abdel-Fatah Bouzidi

doi:10.1007/s11356-021-16754-6

Abstract

In this proposed study, erbium (Er3+)-doped ZnO nanocomposites were prepared through the effective, basic, and green combustion method. The significant effects of Er dopants on the structural, morphological features, dielectric, and optical behaviors of the pure ZnO matrix as well as Er2O3-ZnO nanostructured materials were investigated applying X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transformation infrared (FT-IR) spectroscopy, and UV-Vis spectrophotometer techniques. These results showed that the synthesized Er2O3-ZnO nanocomposites are well polycrystalline. The Er2O3-ZnO nanocomposites are almost uniformly distributed on the surface morphologies. Furthermore, UV-Vis diffuse reflectance spectroscopy, AC electrical conductivity, and dielectric properties' current-voltage characteristics were utilized to examine the influence of erbium doping on the optical properties, energy bandgaps of the proposed Er2O3-ZnO nanostructured powder. The tested nano-samples were applied for the visible light photodegradation of p-chlorophenol(4-CP) and p-nitrophenol (4-NP). The Er-doped ZnO ratio affects the photocatalytic activity of the ZnO matrix. This current research substantiated that more than 99.5% of 4-CP and 4-NP were photodegraded through 30 min of irradiation. Four times, the Er:ZnO nanocatalysts were used and still displayed an efficiency of more than 96.5% for 4-CP and 4-NP degradations in the specified period of 30 min. The as-prepared Er2O3-ZnO nanostructures are considered novel potential candidates in broad nano-applications from visible photocatalytic degradation of waste pollutants to the electronic varistor devices.

Highlights

The nanocrystals are promising candidates to be used as a technological material in different applications, such as bioimaging, solar cells, and tunable lasers, which eventually have a strong dependence on controlling the nanocrystals ’properties through adding impurities as a dopant (Michalet et al 2005)
The significant effects of Er-dopants on the structural, morphological features, dielectric and optical behaviors of the pure zinc oxide (ZnO) matrix as well as Er2O3–ZnO nanostructured materials were investigated applying X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transformation Infrared spectroscopy (FTIR), and UV–Vis spectrophotometer techniques. These results showed that the synthesized Er2O3–ZnO nanocomposites are well polycrystalline
The XRD patterns of undoped ZnO and Er2O3 -ZnO nanocomposite samples are illustrated in Fig. 2, which offer mostly diffraction bands due to the wurtzite ZnO phase (JSPDS 01- 0750576) with weak lines related to the carbon phase (JSPDS 01-072-2091) as reported by Yu et al (2013)

Summary

Introduction

The nanocrystals are promising candidates to be used as a technological material in different applications, such as bioimaging, solar cells, and tunable lasers, which eventually have a strong dependence on controlling the nanocrystals ’properties through adding impurities as a dopant (Michalet et al 2005). The different 1D nanoscale semiconductor has been produced and investigated, including III–V group, carbon group, II-VI group, as well as oxide group materials (Calarco 2005; Iijima and Ichihashi 199; Vayssieres 2003; Mor et al 215) Among those various unique 1D nanoscale oxides, zinc oxide (ZnO) materials have been considered as a great potential candidate to own a structure of n-type wurtzite, considerable energy of exciton binding with 60 meV, and a broad-ranging optical energy bandgap of 3.37 eV at ambient temperature. The outstanding transparent and piezoelectric properties of ZnO semiconductor materials have extended the range of high technology in various applications, including transparent electrodes and wave filters of surface acoustic ( Lee et al 2004) Both zinc interstitials or oxygen vacancies perform significant roles in n-type semiconductor dopants, mainly affecting chemical and physical properties ( Zeng et al 2010; Djurisic et al 2010; Unalan et al 2008; Willander et al 2009)

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Conclusion