Vol.:(0123456789) 1 3 Journal of Materials Science: Materials in Electronics https://doi.org/10.1007/s10854-020-03684-1 Magneto‑structural and photocatalytic behavior of mixed Ni–Zn nano‑spinel ferrites: visible light‑enabled active photodegradation of rhodamine B Swapnil A. Jadhav 1  · Sandeep B. Somvanshi 1  · Mangesh V. Khedkar 1  · Supriya R. Patade 1  · K. M. Jadhav 1 Received: 12 December 2019 / Accepted: 25 May 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract The present study compiles with the physicochemical, magnetic, and photocatalytic evaluation of the mixed spinel Ni–Zn nanoferrites prepared by the auto-combustion sol–gel route. All the samples were characterized by XRD for the recognition of phase-pure cubic spinel structure. Spectral studies that were carried out by FT-IR clearly show two absorptions band revealing the characteristics of ferrite skeleton. The morphology of the prepared nanoparticles was visualized by SEM and TEM microscopy technique. BET analysis showed the enhancement in surface parameters. Hydrodynamic diameter and dispersion studies were evaluated by DLS and Zeta potential measurements. The DC resistivity measured by two-probe technique shows the semiconductor behavior for all the samples. M–H hysteresis loop of all the samples exhibited the super- paramagnetic behavior. The energy bandgap values obtained by the UV–Vis spectroscopy technique show the increasing trend from 1.82 to 2.07 eV with increase in Ni 2+ content. The photocatalytic activity of Rhodamine B was evaluated under sunlight irradiation. With increasing Ni 2+ concentration, the degradation efciency increased to 98%. Further, the present nanocatalyst shows active reusability and can be easily separable due to its magnetic nature. The obtained results show the enhanced photocatalytic of the Ni–Zn nanoferrites under the visible light in contrast with the available literature reports. 1 Introduction Nowadays, the occurrence of toxic organic pollutants due to the development of industries has great efects on the clean environment such as the growth of plants, sea-animals, the fertility of the soil, and human health, therefore it is a seri- ous global issue [1]. Over the past decade, young research- ers focused on to synthesis of low-dimensional nanomateri- als and widely used them in photocatalytic degradation of highly toxic organic pollutants [2]. Many researchers already concluded that low-dimensional materials have large surface area, active adsorptions sites, and electron–hole recombi- nation rate under UV and visible light sources [3]. Rho- damine B is a chemical dye having structure as depicted in Scheme 1. It is generally used in industrials purposes like textiles, paints, paper, biotechnology applications such as fuorescence microscopy, fow cytometry, etc. [4]. The organic dyes may cause serious environmental problems related to eye, skin, and lung tract irritation [5]. So, elimi- nating dye from water is the most important and demanding task. For the wastewater treatment, advanced oxidation process (AOPs) is the best alternative technique in comparison to adsorption, precipitation, and fltration for the degradation of organic pollutants [6]. The AOPs are very simple to operate eco-friendly with high efciency and nonselective process. Generally, the Photocatalytic process is one of the types of AOPs procedure that is widely used for wastewater treat- ment. AOPs mainly includes the production of nonselec- tive as well as enormously reactive hydroxyl radical ( . OH). Hydroxyl radical can be formed by the interaction of Fe 3+ / Fe 2+ ions with H 2 O 2 , where H 2 O 2 works as an oxidizing agent and Fe 3+ /Fe 2+ as catalyst [7–9]. Spinel ferrite nanomaterials ofer photocatalytic prop- erties, which are useful in various degradation of organic pollutants in wastewater [10]. The general formula of spi- nel ferrite nanoparticles is AFe 2 O 4 (A can be Mn, Mg, Ni, Zn, etc.) [11–13] where A and Fe are metal cations which occupy tetrahedral and the octahedral sites, respectively * K. M. Jadhav drjadhavkm@gmail.com 1 Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, Maharashtra 431004, India