Surface, optical and photocatalytic properties of Rb doped ZnO nanoparticles

Kumar, Promod; Kumar, Ashish; Rizvi, Masood Ahmad; Moosvi, Syed Kazim; Krishnan, Venkata; Duvenhage, Mart‐Mari; Roos, W.; Swart, H.C.

doi:10.1016/j.apsusc.2020.145930

Cited by 93 publications

(46 citation statements)

References 43 publications

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“…This is consistent with the emission of 2p photoelectrons from ZnO [ 33 ]. The shoulder of Zn 2p in Figure 5 c is centered at 1019.27 eV and can be associated with the Zn broken bonds or O vacancies [ 39 , 40 ]. Additionally, the peak at 139.6 eV appearing in the Gd 4d spectra can be ascribed to the Gd4d 5/2 , showing that the oxidation state of Gd ions in the NPs is +3, which exist in the form of Gd 2 O 3 [ 41 ].…”

Section: Resultsmentioning

confidence: 99%

Facile Chemical Synthesis of Doped ZnO Nanocrystals Exploiting Oleic Acid

et al. 2020

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Zinc oxide nanocrystals (ZnO-NCs) doped with transition metal elements or rare earth elements can be probed for magnetic resonance imaging to be used as a molecular imaging technique for accurate diagnosis of various diseases. Herein, we use Mn as a candidate of transition metal elements and Gd as a presenter of rare earth elements. We report an easy and fast coprecipitation method exploiting oleic acid to synthesize spherical-shaped, small-sized doped ZnO-NCs. We show the improved colloidal stability of oleate-stabilized doped ZnO-NCs compared to the doped ZnO-NCs synthesized by conventional sol–gel synthesis method, i.e., without a stabilizing agent, especially for the Mn dopant. We also analyze their structural, morphological, optical, and magnetic properties. We are able to characterize the persistence of the crystalline properties (wurtzite structure) of ZnO in the doped structure and exclude the formation of undesired oxides by doping elements. Importantly, we determine the room-temperature ferromagnetism of the doped ZnO-NCs. This oleate-stabilized coprecipitation method can be subjected as a standard procedure to synthesize doped and also co-doped ZnO-NCs with any transition metal elements or rare earth elements. In the future, oleate-stabilized Gd/Mn-doped ZnO-NCs can be exploited as magnetic resonance imaging (MRI) contrast agents and possibly increase the signal intensity on T1-weighted images or reduce the signal intensity on T2-weighted images.

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Section: Resultsmentioning

confidence: 99%

Facile Chemical Synthesis of Doped ZnO Nanocrystals Exploiting Oleic Acid

et al. 2020

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“…All diffractograms were identified according to the same precursor oxide card (ICDD #36-1451). As described in the literature (Dib, Trari, & Bessekhouad, 2020;Promod Kumar et al, 2020;Poornaprakash, Chalapathi, Subramanyam, Vattikuti, & Park, 2020), this crystalline structure corresponds to the active phase for most required ZnO applications. Small peaks (on the magnification of Figure 1 (a)) indicate Fe presence (ICDD # 6-696).…”

Section: Resultsmentioning

confidence: 58%

“…The authors achieved high percentage of degradation using a milling time of 40h. Doping using several metal ions have also been used to enhance the ZnO optical and catalytic activity, such as Cu (Chandekar et al, 2020;Jiang et al, 2019), Co (Gonçalves, Paganini, Armillotta, Cerrato, & Calza, 2019), Fe (Reddy et al, 2019;Yin et al, 2017), among others (Khalid et al, 2019;Promod Kumar et al, 2020). Sharma et al (2016) (N. Sharma, Jandaik, & Kumar, 2016) also demonstrated that doping ZnO nanoparticles with Fe showed improved antimicrobial activity.…”

Section: Introductionmentioning

confidence: 99%

Influence of the shaker mill in the properties of ZnO processed by high energy milling

Storion

Pallone

Giraldi

et al. 2021

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This work evaluates how the High Energy Ball Milling (HEBM) in a shaker mill influences the optical, physical, and microstructural properties of ZnO. The procedure also combines Fe inclusion from the grinding medium with particle size reduction. ZnO powder was milled by 1, 2, 3, 4, and 5 h, which resulted in a particle size reduction to the nanometric scale with a mean size of around 50 nm and a crystallite size reduction by three times when processed from 4 h. Milling has proven to be an efficient process for obtaining nanoparticles with an incredibly short processing time and changed the morphology of the particles from random to spherical shapes. Results also indicate the processing progressively expanded the ZnO hexagonal structure due to the imposed strain and Fe inclusion, which can help to decrease the bandgap and slow down the recombination rate of the electron-hole pairs, improving the photocatalysis activity. The optical results showed no additional band appeared due to milling processes and diminished the bandgap from 3.37 to 3.21 eV. Milling also led to an increase in the c value from 5.2076 to 5.2112 Å, which is one of the most important factors for improved antibacterial activity. HEBM has proved to be a suitable process for obtaining ZnO nanoparticles with properties useful for various applications.

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“…According to the photoluminescence study, the intensity of a PL spectrum increases as the charge recombination of electron-hole pairs increases and vice versa. 53,54 The PL spectra of bare BiOBr and g-C 3 N 4 and the BiOBr/g-C 3 N 4 composite are shown in Fig. 12a.…”

Section: Mechanism Of Photocatalytic Activitymentioning

confidence: 99%