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Tahir Iqbal, M. Irfan, Shahid M. Ramay, Abdullah Alhamidi, Hamid Shaikh, Murtaza Saleem, Saadat A. Siddiqi. Mg and Ni Incorporated ZnO Diluted Magnetic Semiconductor for Magnetic and Photo-Catalytic Applications[J]. Chinese Journal of Chemical Physics , 2020, 33(6): 743-748. doi: 10.1063/1674-0068/cjcp1908157
Citation: Tahir Iqbal, M. Irfan, Shahid M. Ramay, Abdullah Alhamidi, Hamid Shaikh, Murtaza Saleem, Saadat A. Siddiqi. Mg and Ni Incorporated ZnO Diluted Magnetic Semiconductor for Magnetic and Photo-Catalytic Applications[J]. Chinese Journal of Chemical Physics , 2020, 33(6): 743-748. doi: 10.1063/1674-0068/cjcp1908157

Mg and Ni Incorporated ZnO Diluted Magnetic Semiconductor for Magnetic and Photo-Catalytic Applications

doi: 10.1063/1674-0068/cjcp1908157
More Information
  • Zinc oxide is recently being used as a magnetic semiconductor with the introduction of magnetic elements. In this work, we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure, optical, magnetic and photo-catalytic properties. X-ray diffraction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase. UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix. Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices. Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions.
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  • [1] M. Saleem, A. Manzoor, M. Zaffar, S. Z. Hussain, and M. S. Anwar, Appl. Phys. A 122, 589 (2016).
    [2] M. Tosun, S. Ataoglu, L. Arda, O. Ozturk, E. Asikuzun, D. Akcan, and O. Cakiroglu, Mater. Sci. Eng. A 590, 416 (2014).
    [3] Z. K. Heiba, L. Arda, M. B. Mohammed, Y. M. Nasser, and N. Dogan, J. Supercond. Nov. Magn. 26, 3487 (2013).
    [4] M. S. Shafiq, M. Furqan, S. Atiq, M. Saleem, S. Riaz, and S. Naseem, J. Sol-Gel Sci. Technol. 79, 535 (2016).
    [5] M. Saleem, M. S. Anwar, A. Mahmood, S. Atiq, S. M. Ramay, and S. A. Siddiqi, Phys. B Condensed Matter 465, 16 (2015).
    [6] C. Boyraz, B. Yesilbas, and L. Arda, J. Supercond. 30, 1691 (2017).
    [7] L. Arda, M. Acikgoz, Z. K. Heiba, N. Dogan, D. Akcan, and O. Cakiroglu, Solid State Commun. 170, 14 (2013).
    [8] A. Goktas, I. H. Mutlu, and Y. Yamada, Superlattice Microstruct. 57, 139 (2013).
    [9] Z. K. Heiba, L. Arda, M. B. Mohammed, M. A. Al-Jalali, and N. Dogan, J. Supercond. Nov. Magn. 26, 3299 (2013).
    [10] Z. K. Heiba, L. Arda, and M. B. Mohammed, J. Magn. Magn. Mater. 389, 153 (2015).
    [11] A. Tumbul, F. Aslan, S. Demirozu, A. Goktas, A. Kilic, M. Durgun, and M. Z. Zarbali, Mater. Res. Express 6, 035903 (2019).
    [12] P. Fons, K. Iwata, S. Niki, A. Yamada, K. Matsubara, and M. Watanabe, J. Cryst. Growth 209, 532 (2000).
    [13] S. Boumaza, A. Boudjemaa, A. Bouguelia, R. Bouarab, and M. Trari, Appl. Energy 87, 2230 (2010).
    [14] S. Ida, K. Yamada, T. Matsunaga, H. Hagiwara, Y. Matsumoto, and T. Ishihara, J. Am. Chem. Soc. 132, 17343 (2010).
    [15] E. Casbeer, V. K. Sharma, and X. Z. Li, Sep. Purif. Technol. 87, 1 (2012).
    [16] R. Dom, R. Subasri, K. Radha, and P. H. Borse, Solid State Commun. 151, 470 (2011).
    [17] X. Su, G. Duan, Z. Xu, F. Zhou, and W. Cai, J. Colloid Interface Sci. 503, 150 (2017).
    [18] P. V. Dorpe, V. F. Motsnyi1, and M. Nijboer, Jpn. J. Appl. Phys. 42, L502 (2003).
    [19] G. Bouzerar and T. Ziman, Phys. Rev. Lett. 96, 207602 (2006).
    [20] M. Saleem, S. A. Siddiqi, S. M. Ramay, S. Atiq, and S. Naseem, Chin. Phys. Lett. 29, 106103 (2012).
    [21] L. T. Chang, C. Y. Wang, and J. Tang, Nano Lett. 14, 1823 (2014).
    [22] J. Tang, C. Y. Wang, L. T. Chang, and Y. Fan, Nano Lett. 13, 4036 (2013).
    [23] S. Atiq, M. Majeed, A. Ahmad, S. K Abbas, M. Saleem, S. Riaz, and S. Naseem, Ceram. Int. 43, 2486 (2017).
    [24] M. Saleem, S. Atiq, S. Naseem, and S. A Siddiqi, J. Korean Phys. Soc. 60, 1772 (2012).
    [25] X. L. Tang, S. L. Young, C. Y. Kung, M. C. Kao, H. Z. Chen, and C. J. Ou, Thin Solid Films 649, 75 (2018).
    [26] A. Samanta, M. N. Goswami, and P. K. Mahapatra, J. Alloys Compd. 730, 399 (2018).
    [27] J. N. Alexander, N. Sun, R. Sun, H. Efstathiadis, and P. Haldar, J. Alloys Compd. 633, 157 (2015).
    [28] N. Kumar and A. Srivastava, J. Alloys Compd. 735, 312 (2018).
    [29] A. Goktas, A. Tumbul, Z. Aba, and M. Durgun, Thin Solid Films 680, 20 (2019).
    [30] A. Goktas, F. Aslan, B. Yesilata, and I. Boze, Mat. Sci. Semicon. Proc. 75, 221 (2018).
    [31] A. Goktas, J. Alloy Compd. 735, 2038 (2018).
    [32] S. Fabbiyola, V. Sailaja, L. J. Kennedy, M. Bououdina, and J. J. Vijaya, J. Alloy Compd. 694, 522 (2017).
    [33] M. Saleem, S. A. Siddiqi, S. Atiq, M. S. Anwar, I. Hussain, and S. Alam, Mater Charact. 62, 1102 (2011).
    [34] M. S. Abdel-Wahab, A. Jilani, I. S. Yahia, and A. A. Al-Ghamdi, Superlattice Microst. 94, 108 (2016).
    [35] S. M. Mousavi, A. R. Mahjoub, and R. Abazari, J. Mol. Liq. 242, 512 (2017).
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Mg and Ni Incorporated ZnO Diluted Magnetic Semiconductor for Magnetic and Photo-Catalytic Applications

doi: 10.1063/1674-0068/cjcp1908157

Abstract: Zinc oxide is recently being used as a magnetic semiconductor with the introduction of magnetic elements. In this work, we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure, optical, magnetic and photo-catalytic properties. X-ray diffraction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase. UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix. Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices. Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions.

Tahir Iqbal, M. Irfan, Shahid M. Ramay, Abdullah Alhamidi, Hamid Shaikh, Murtaza Saleem, Saadat A. Siddiqi. Mg and Ni Incorporated ZnO Diluted Magnetic Semiconductor for Magnetic and Photo-Catalytic Applications[J]. Chinese Journal of Chemical Physics , 2020, 33(6): 743-748. doi: 10.1063/1674-0068/cjcp1908157
Citation: Tahir Iqbal, M. Irfan, Shahid M. Ramay, Abdullah Alhamidi, Hamid Shaikh, Murtaza Saleem, Saadat A. Siddiqi. Mg and Ni Incorporated ZnO Diluted Magnetic Semiconductor for Magnetic and Photo-Catalytic Applications[J]. Chinese Journal of Chemical Physics , 2020, 33(6): 743-748. doi: 10.1063/1674-0068/cjcp1908157
  • Zinc oxide (ZnO) based diluted magnetic semiconductor (DMS) materials are currently being used extensively in magneto-optic, optoelectronic and spintronic devices [1-5]. ZnO doped with magnetic elements, as well as co-doped with some other elements, exhibits stimulating changes in physical properties and makes them more appealing candidate for various applications [6]. ZnO is a wide band gap (3.3 eV) semiconductor with large binding energy [7]. A key characteristic of ZnO based DMSs is that the electrical and magnetic properties of these materials can be tuned with doping of some other elements [6-10]. Importantly, band gap engineering of ZnO has already been reported by many researchers in Mg-doped compositions synthesized using various techniques [10-12]. ZnO has high exciton binding energy and therefore is preferably used as ultraviolet (UV) to the visible converter with the addition of Au, Ag, Pt, Co, etc. [13-16]. In addition, nanoparticles and thin films of DMSs are currently gaining interest in advanced electronic-based industries [17]. The origin of ferromagnetism in DMSs is still under discussion among research groups [18, 19] and different compositions with varying concentrations of additional dopants need to be optimized for further analysis and improvement in device functionalities [20-22]. It was reported that band gap of ZnO decreased while magnetization was introduced with doping of magnetic elements. However, the band gap is usually enhanced with doping of Mg in ZnO and therefore can be used for stabilization. Wide band gap ZnO can be useful for high temperature, high voltage, and photo-catalytic applications. Hence, in this work, we made an attempt to explore the structure, morphology, optical, magnetic and photo-catalytic activity in brief for ZnO and co-doped Mg and Ni compositions.

  • Mg and Ni co-doped ZnO nanoparticles were synthesized using a self-combustive sol-gel method. The ingredients used such as zinc nitrate hexahydrate Zn(NO$_3$)$_2$$\cdot$6H$_2$O, magnesium nitrate hexahydrate Mg(NO$_3$)$_2$$\cdot$6H$_2$O, and nickel nitrate hexahydrate Ni(No$_3$)$_2$$\cdot$6H$_2$O were of analytical research-grade, purchased from Sigma Aldrich. Anhydrous citric acid was used as fuel agent with 1:1 ratio of metal nitrate to citric acid. The other details of the method have already been given in Refs.[23, 24]. Finally the obtained powder samples were calcined at 600 ℃ for 4 h for the establishment of crystalline phase. Structural analysis for phase identification was performed using Bruker D-2 phaser X-ray diffractometer (XRD) operating with Cu K$\alpha$ radiation ($\lambda$=1.5406 Å) at 30 kV and 10 mA. An FEI Nova 450, field emission scanning electron microscope (FESEM) was employed for morphological analysis. Quantitative as well as qualitative elemental composition analysis was carried out using Oxford Instruments Inca X-Act energy dispersive X-ray spectrometry (EDS). The absorbance spectra were obtained using Shimadzu UV-1800 ultraviolet-visible (UV-Vis) spectrophotometry and corresponding values of band gaps were extracted. Magnetic measurements were performed using cryogenic vibrating sample magnetometer (VSM) at room temperature using a magnetic field of $\pm$0.5 T.

  • The XRD patterns of un-doped and doped ZnO samples are presented in FIG. 1. The reflected intensities corresponding to hkl planes in all the compositions are exactly matched with the JCPD reference pattern (No.01-80-0075), a standard reference card for ZnO, exhibiting wurtzite type structure with P63mc space group. It has already been reported that the crystal structure of ZnO is not disturbed with doping concentrations up to 15% [5, 24], as it can also be observed from the XRD spectra of Mg and Ni-doped compositions. The ionic radii of Mg$^{2+}$ and Ni$^{2+}$ are significantly smaller than that of Zn$^{2+}$, so the atoms of dopants have the capability to exactly substitute the Zn sites in the crystal structure [25, 26]. The estimated lattice constants, $a$ and $c$ for the wurtzite structure were calculated and a significant variation was found with Mg and Ni contents, lying in the range of 3.233-3.259 Å and 5.177-5.215 Å, respectively. Average values of crystallite sizes were calculated using Scherrer's relation [1] and found to decrease from 37.39 nm for un-doped ZnO to 23.84 nm for doped compositions corroborating the disturbance in structure with dopants. The variation of lattice parameters and change in crystallite size are attributed to the previously defined substitution of elements with smaller ionic radii at Zn sites. Similarly, a small decrease in unit cell volume from 47.968 Å$^3$ to 46.862 Å$^3$ was also witnessed as a result of the unit cell shrinkage. The strain in the lattice for undoped and doped compositions was determined using Williamson-Hall analysis [1] from XRD data and found to increase with doping as expected, and the doping of Mg and Ni in ZnO matrix revealed a change in crystallite size and cell volume, which can be witnessed as a result of the unit cell shrinkage. The values of most intense (101) reflection, lattice constants, average crystallite sizes, cell volume, and lattice strain are presented in Table Ⅰ and FIG. 2.

    Figure 1.  XRD patterns of (a) ZnO, (b) Zn$_{0.95}$Mg$_{0.05}$O, (c) Zn$_{0.90}$Mg$_{0.05}$Ni$_{0.05}$O, and (d) Zn$_{0.85}$Mg$_{0.05}$Ni$_{0.10}$O.

    Table Ⅰ.  Position of (101) reflection, lattice constants, crystallite size, cell volume, lattice strain, band gap $E_\textrm{g}$, coercivity $H_\textrm{c}$, saturation magnetization $M_\textrm{s}$, and remanent magnetization $M_\textrm{r}$ values of all compositions

    Figure 2.  Lattice constants, crystallite size, cell volume, and lattice strain of Mg and Ni incorporated ZnO nanaoparticles.

  • FIG. 3 presents FESEM images of un-doped and doped ZnO compositions. It can be seen that morphology has been significantly changed with the doping of Mg and Ni contents. In FIG. 3(a), the un-doped ZnO composition reveals more uniform and ordered morphology with clear nano-sized particles of diameter in the range of 50-250 nm. The size of particles is found to decrease significantly with additional doping of Mg and Ni, as shown in FIG. 3 (b-d), due to the smaller ionic radii of dopants than Zn. It can be seen from FIG. 3(d) that morphology of Zn$_{0.85}$Mg$_{0.05}$Ni$_{0.10}$O has a bit difference due to the maximum concentration of Mg and Ni dopants in this composition. EDX spectra with quantitative analysis as given in FIG. 4 and Table Ⅱ confirmed the presence of required elements in each composition.

    Figure 3.  FESEM micrographs of (a) ZnO, (b) Zn$_{0.95}$Mg$_{0.05}$O, (c) Zn$_{0.90}$Mg$_{0.05}$Ni$_{0.05}$O, and (d) Zn$_{0.85}$Mg$_{0.05}$Ni$_{0.10}$O.

    Figure 4.  EDX spectra of (a) ZnO, (b) Zn$_{0.95}$Mg$_{0.05}$O, (c) Zn$_{0.90}$Mg$_{0.05}$Ni$_{0.05}$O, and (d) Zn$_{0.85}$Mg$_{0.05}$Ni$_{0.10}$O.

    Table Ⅱ.  Elemental compositions of samples calculated using EDX analysis.

  • FIG. 5 shows the Tauc plot data extracted using UV-Vis spectrophotometry. Absorption coefficient and photon energy can be used to implement the Tauc model using the relation, ($\alpha h\nu$)=$A$($h\nu$-$E_\textrm{g}$)$^n$ [1, 27], where the notations $\alpha$, $h \nu$, $A$, $E_\textrm{g}$, and $n$ present absorption coefficient, photon energy, proportionality constant, optical band gap energy, and an integer, respectively. The band gap values were extracted by extra plotting the Tauc curves towards the energy axis ($X$-axis) as shown in graphs. The band gap of Mg-doped composition was found to increase with Mg content as also reported in a recent paper [28]. The doping of Mg in ZnO introduced more electrons which located at some higher fermi levels than host material consequently widening the energy band gap [29]. It was again decreased to some extent with additional doping of Ni contents but overall values showed an enhanced band gap than the host ZnO. The extracted values of the band gap were observed between minimum of 3.30 eV for ZnO and maximum of 3.41 eV for doped composition mentioned in Table Ⅰ for each composition.

    Figure 5.  Band gap analysis from UV-Vis measurements for (a) ZnO, (b) Zn$_{0.95}$Mg$_{0.05}$O, (c) Zn$_{0.90}$Mg$_{0.05}$Ni$_{0.05}$O, and (d) Zn$_{0.85}$Mg$_{0.05}$Ni$_{0.10}$O.

  • Magnetic hysteresis ($M-H$) loops were attained using VSM at an applied magnetic field of $\pm$0.5 T as presented in FIG. 6. There is very small magnetization that appeared in un-doped and Mg-doped ZnO composition at very low applied fields which might be due to the already reported defect induced magnetization in ZnO with addition to high field diamagnetic behavior. However, Mg and Ni co-doped compositions show clear ferromagnetic behavior with prominent saturation magnetization as evident from $M-H$ curves. Ferromagnetism in magnetic elements doped ZnO has already been reported by many research groups with a significant change in the band gap as well. The saturation magnetization ($M_\textrm{s}$), coercive field ($H_\textrm{c}$), and remanent magnetization ($M_\textrm{r}$) were found to vary with dopant contents as given in Table Ⅰ and FIG. 7, however, band gap retained its higher value than un-doped ZnO composition. The origin of ferromagnetism in ZnO based dilute magnetic semiconductors remained controversial among the researchers. Goktas et al. [30, 31] reported the enhanced magnetization in ZnO with additional doping of Al related to the oxygen vacancies, inter-granular boundaries and quality of crystallinity in materials. The origin of ferromagnetism in Ni-doped ZnO NPs was recently reported and attributed to the bound magnetic polaron mechanism [32]. The abrupt increase in magnetization with Ni content corroborates the strong magnetic nature originating from Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions as described in detail in our previously work [33].

    Figure 6.  $M-H$ loops of (a) ZnO, (b) Zn$_{0.95}$Mg$_{0.05}$O, (c) Zn$_{0.90}$Mg$_{0.05}$Ni$_{0.05}$O, and (d) Zn$_{0.85}$Mg$_{0.05}$Ni$_{0.10}$O.

    Figure 7.  Coercivity ($H_\textrm{c}$) and saturation magnetization ($M_\textrm{s}$) of (a) ZnO, (b) Zn$_{0.95}$Mg$_{0.05}$O, (c) Zn$_{0.90}$Mg$_{0.05}$Ni$_{0.05}$O, and (d) Zn$_{0.85}$Mg$_{0.05}$Ni$_{0.10}$O.

  • The samples were analyzed for degradation of methyl green dye with its solution of 1$\times$10$^{-4}$ mol/L concentration in deionized water. A glass reactor was used for photo-catalytic analysis containing a 100 mL aqueous methyl green solution. The lamp was mounted vertically at 25 cm distance from the reactor by evading the solution from direct heating. The absorption spectra were taken every 30 min to analyze the variation in the concentration of methyl green dye. The percentage of degradation was calculated using the relation:

    where $C_0$ and $C_t$ are concentrations of methyl green at initial and after specific time $t$ for the duration of the catalytic reaction. FIG. 8 shows the variation of percentage degradation with the time of all the samples reveal an increasing trend with time and doping of Mg and Ni contents. The enhanced trend of photo-catalytic activity was reported in literature in the similar type of ZnO compositions that were attributed to the surface roughness, band gap variation, and enhanced surface area [34]. It was also found in another study for Ni doped ZnO compositions that morphology and size of nanostructures strongly influenced the photo-catalytic efficiency [35]. Apparent rate constant ($k_{\textrm{app}}$) for the decomposition of MG dye has been described by Langmuir Hinshelwood kinetics model: ln($C_0/C_t)$ =$k_{\textrm{app}}$$t$, where $t$ denotes for the irradiation time. FIG. 9 presents the variation in $C_t$/$C_0$ with time, exhibiting that the decreasing trend with time and doping contents followed the pseudo-first-order kinetics for degradation of methyl green dye.

    Figure 8.  Photo-catalytic activity (% degradation) of MG for (a) ZnO, (b) Zn$_{0.95}$Mg$_{0.05}$O, (c) Zn$_{0.90}$Mg$_{0.05}$Ni$_{0.05}$O, and (d) Zn$_{0.85}$Mg$_{0.05}$Ni$_{0.10}$O.

    Figure 9.  Photo-catalytic activity ($C_t$/$C_0$) of MG for (a) ZnO, (b) Zn$_{0.95}$Mg$_{0.05}$O, (c) Zn$_{0.90}$Mg$_{0.05}$Ni$_{0.05}$O, and (d) Zn$_{0.85}$Mg$_{0.05}$Ni$_{0.10}$O.

  • Mg and Ni co-doped ZnO compositions were successfully synthesized using a self-combustive sol-gel method. X-ray diffraction studies reveal the presence of wurtzite type hexagonal crystal structure in all compositions without traces of any impurity phase. Morphological studies are exactly correlated with the structural analysis with respect to shape, size, and distribution of particles. EDX analysis confirmed the presence of doping contents in all compositions. It was observed that the band gap of pure ZnO increased with doping of Mg and then again decreased with additional doping contents of Ni showing the band gap stability of ZnO with co-doping. Magnetic properties disclose the room temperature magnetization in Ni-doped concentration and display a boosted enhanced magnetization with Ni-contents. Photo-catalytic measurements reveal an enhanced activity in doped compositions.

  • The work was supported by the Deanship of Scientific Research at King Saud University for funding under Research Group (No.RG1440-021).

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