Enhanced Photo Catalytic Activity of ZnO Nano Particles Co-doped with Rare Earth Elements (Nd and Sm) Under UV Light Illumination

P Baskaran,A Pramothkumar,P Mani

doi:10.1007/s10904-022-02228-w

P Baskaran, A Pramothkumar + Show 1 more

Open Access

https://doi.org/10.1007/s10904-022-02228-w

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Abstract

In the present report, synthesis of zinc oxide (ZnO) nano particles (NPs) in pure form, 1 wt% of neodymium (Nd)-doped and 1 wt% of neodymium (Nd) and samarium (Sm) co-doped ZnO NPs in doped form by using simple co-precipitation method (samples namely PZ as pure, NZ as Nd-doped ZnO and NSZ as Nd–Sm co-doped ZnO NPs). Powder X-ray diffraction patterns of all the synthesized samples expose the hexagonal crystal structure of ZnO NPs without any impurity. The various functional groups presented in the synthesized samples were analyzed by Fourier-transform infrared spectroscopy studies. From Ultraviolet (UV)–Visible Diffuse Reflectance Spectroscopy (DRS), the band gap was found to be 2.81 eV, 2.90 eV and 3.10 eV respectively for pure, Nd-doped and Nd–Sm co-doped ZnO NPs. Photoluminescence (PL) spectrum displays the broad emission at 393 nm and 450 nm for all the synthesized samples. The agglomeration of flower-like morphology of pure ZnO NPs, flake-like structure of Nd-doped and rod-like morphology of Nd–Sm co-doped ZnO NPs were examined by scanning electron microscopy. The surface chemical composition of samples was carried out with X-ray photoelectron spectroscopy. The photocatalytic activity of the prepared samples for dye degradation of acid orange 7 (AO-7) and acid red 13 (AR-13) was studied under UV light. The result revealed that, the Nd–Sm co-doped ZnO NPs found to have efficient degradation candidate materials.

Highlights

Zinc Oxide (ZnO) NPs is a versatile n-type semiconducting material in the II-VI group elements with a direct band gap of 3.37eV and possess the most varied nanocrystalline designs
The clean environmental, safe drinking water and sufficient energy are highly polluted by several dyes coming out from the various factories like leather, textiles, printing, cosmetics, hair colouring, medical laboratories, convulsions mutagenic, plastics, foods, pharmaceuticals, teratogenic and other industries.In addition, most industrials dyes are soluble in water and which can cause severe disorders on aquatic organisms, humans and animals due to their high toxicity, low biodegradability, stability and mutability [9,10].In past few years, several techniques have been used for the removal of organic dye pollutants from the industrials waste water. among them, the photocatalysis methods is great treatment for the removal of organic dye pollutants from the industrial waste water due to low cost and environmentally friendly [11]
For each interval of time, the C/C0 was computed and a plot was sketched between successive C/C0 values to corresponding reaction time periods for all synthesized materials pure ZnO (PZ), Nd doped ZnO (NZ) and Nd-Sm co-doped ZnO NPs (NSZ NPs) to evaluate the proportion of the dye molecules destruction and is being illustrated in Fig. 11 (A & B) for AO 7 and AR 13 dyes, respectively

Summary

Introduction

ZnO NPs is a versatile n-type semiconducting material in the II-VI group elements with a direct band gap of 3.37eV and possess the most varied nanocrystalline designs It has high exciton energy (60 meV), hexagonal wurtzite structure, low resistivity, good transparency, high electron mobility, non-toxicity, high photo stability and has been used a countless remarkable applications like opto-electronics, solar cell, spintronics, sensors, gas sensors, antimicrobial, photoconductive, photocatalytic, PN junction diode liquid crystal display, magnetic storage media, lithium-ion battery and laser source [1,2,3,4,5]. Where c0 is the preliminary dye solution intensity before illumination and c is the dye solution intensity after illumination with light at time (t)

Results and discussion

Reaction mechanism for the degradation process:

Conclusion