Characterization of single phase Pt-doped Zn2TiO4 nanoparticles synthesized by flame spray pyrolysis
Highlights
► Synthesis of single phase Pt-doped Zn2TiO4 nanoparticles by Flame spray pyrolysis (FSP) was reported for the first time. ► The crystallite sizes were in the range of 5–18 nm from the TEM images. ► The SSABET was in the range of 165.0 to 197.3 m2/ cm3 corresponding to dBET of 6.9 to 5.7 nm.
Introduction
ZnO–TiO2 system has been used in paint pigment, gas sensor and catalytic sorbent [1], [2], [3]. Three compounds are known to exist in the ZnO–TiO2 system, namely: Zn2TiO4 (cubic), ZnTiO3 (hexagonal) and Zn2Ti3O8 (cubic) [4]. The h-ZnTiO3 decomposes into rutile TiO2 and cubic Zn2TiO4 when the temperature exceeds 945 °C. Cubic Zn2Ti3O8 has been regarded as a low-temperature phase of h-ZnTiO3, stabled at ~ 600–800 °C and transformed into h-ZnTiO3 at ~ 820 °C. Zn2TiO4 can easily be prepared by conventional solid state reaction between 2ZnO and 1TiO2 [5], [6]. Various crystalline phases and the stabilized temperature in the ZnO–TiO2 system are shown in Table 1. Other preparation methods were reported in literature [7], [8], [9], [10], [11]. All the mentioned preparation methods did not yield the stabilized final product of Zn2TiO4. Doping Zn2TiO4 with metals or metal oxides improved several properties such as photoluminescence [8], microwave dielectric [12], optical [13], and gas sensing [14], [15].
Flame spray pyrolysis (FSP) has previously been used to synthesize undoped ZnO and Nb-doped ZnO [16], [17]. FSP is a very promising technique for synthesis of high purity nano-sized materials with controlled size and high surface area in one step. The FSP synthesis was reported in the literature. The aim of this research is to apply this technique to synthesize the single phase undoped Zn2TiO4 and Pt-doped Zn2TiO4 nanoparticles. Characterization of the undoped Zn2TiO4 and Pt-doped Zn2TiO4 nanoparticles was also performed. Doping of Zn2TiO4 with Pt has never been reported before.
Section snippets
Flame synthesis of nanoparticles
Zinc naphthenate (Aldrich, 8 wt.% Zn), titanium tetra isopropoxide (Aldrich) and platinum (II) acetylacetonate were used as precursors. The precursors were dissolved in ethanol (Carlo Erba, 98.5%) to obtain a 0.5 mol/L precursor solution. The FSP synthesis has been reported in the literature [18].
Powder characterizations
X-ray diffraction (XRD) patterns were recorded with a JEOL JDX-3530 operating with Cu Kα. The BET surface area (SSABET) of the nanoparticles was measured by nitrogen adsorption at 77 K (Micromeritics
Particle properties
Fig. 1 shows the XRD patterns of the single phase undoped Zn2TiO4 and Pt-doped Zn2TiO4 nanoparticles. All peaks can be confirmed to correspond to the cubic structure of Zn2TiO4 (JCPDS No. 25-1164). However, diffraction peaks of Pt are not found in this pattern. This absence should be due to the fact that concentrations of Pt are very low and XRD does not have sufficient sensitivity to detect it.
The specific surface areas (SSABET) from BET method of undoped Zn2TiO4 and Pt-doped Zn2TiO4
Conclusions
In summary, we have shown that FSP is a promising technique for the synthesis of high purity nano-sized materials with controlled size and crystallinity in a single step of the single phase undoped Zn2TiO4 and Zn2TiO4 nanoparticles doped with 0.25–1.00 mol% Pt under 5/5 (precursor/oxygen) flame conditions. All peaks in the XRD spectrum can be confirmed to correspond to the cubic structure of Zn2TiO4 (JCPDS No. 25-1156). The SEM result showed the presence of agglomerated nanospheres with an
Acknowledgments
The authors would like to gratefully acknowledge the financial support from the National Research University Project under the Office of the Higher Education Commission, Ministry of Education, Thailand.
References (20)
- et al.
J Cryst Growth
(2009) - et al.
J Alloy Compd
(2009) - et al.
Mater Chem Phys
(2007) - et al.
Ceram Inter
(2004) - et al.
J Alloy Compd
(2009) - et al.
Mater Lett
(2005) - et al.
J Solid State Chem
(2006) - et al.
Mater Chem Phys
(2003) - et al.
J Alloy Compd
(2010) - et al.
J Alloy Compd
(2009)
Cited by (15)
Closed-cell polyurethane spray foam obtained with novel TiO<inf>2</inf>–ZnO hybrid fillers – mechanical, insulating properties and microbial purity
2023, Journal of Building EngineeringCitation Excerpt :The X-ray patterns for TiO2 (black curve) and TiO2–ZnO (purple curve) indicate the presence of TiO2 with an anatase structure (JCPDS no. 21–1272), which is evidenced by diffraction peaks visible at 2θ=25.28, 36.95, 37.80, 38.58, 48.05, 53.89, 55.06, 62.69, 68.76, 70.31, and 75.03. In the case of the TiO2–ZnO filler, diffraction peaks were also observed at 2θ=27.45 and 30.15 (with low intensity), these being specific to TiO2 with a rutile structure (JCPDS no. 21–1279) and Zn2TiO4 (JCPDS no. 25–1164) [37], respectively. The diffractogram for TiO2–ZnO also contains a diffraction peak at 2θ=25.09, which can be assigned to the zinc titanate (ZnTiO3) structure (JCPDS no. 39–0190) [38,39].
Synthesis of nanomaterials for biofuel and bioenergy applications
2021, Nanomaterials: Application in Biofuels and Bioenergy Production SystemsZn<inf>2</inf>TiO<inf>4</inf>: A novel host lattice for Sm<sup>3+</sup> doped reddish orange light emitting photoluminescent material for thermal and fingerprint sensor
2017, Optical MaterialsCitation Excerpt :Zn2TiO4 is a novel host from ZnO-TiO2 system which has its applications in different sensors [1–3]. Zn2TiO4 prepared by conventional solid state reaction method [4,5] and flame spray pyrolysis [6] was reported. All these synthesis methods did not yield the stabilized final product of Zn2TiO4.
Flame-spray-made Zn-In-O alloyed nanoparticles for NO<inf>2</inf> gas sensing
2016, Journal of Alloys and CompoundsCitation Excerpt :Zinc naphthenate (Aldrich, 8 wt% Zn) and indium (III) nitrate hydrate (Aldrich, 99.9%) were dissolved in ethanol (Carlo Erba, 98.5%) to obtain a 0.5 mol/L precursor solution with varying Zn metallic content from 0, 25, 33, 40, 50–100%. The details of FSP synthesis system and process were previously reported by our group [21,22]. In a typical synthesis procedure, the precursor was fed into a FSP reactor by a syringe pump with a flow rate of 5 mL/min and then dispersed into droplets by 5 L/min of O2 (referred to as 5/5 flame condition).
Zn<inf>2</inf>TiO<inf>4</inf>:Eu<sup>3+</sup> nanophosphor: Self explosive route and its near UV excited photoluminescence properties for WLEDs
2015, Spectrochimica Acta - Part A: Molecular and Biomolecular SpectroscopyCitation Excerpt :During the exothermic reaction with metal nitrates and organic fuel complexes at low temperature, sufficient heat was generated locally to form crystalline materials [3]. Recently various titanate hosts were well studied by doping with rare earth and transition metal ions namely CaTiO3:Eu3+ [16], Zn2TiO4:Pt [17], Zn2TiO4:Sn4+, Cr3+, V5+ [18] etc. Normally titanate samples required high calcinations temperature to get single pure phase, Table 1 shows Zn2TiO4 hosts prepared by different methods [18–23].
Sol-gel synthesis of ZnO/Zn<inf>2-x</inf>Fe<inf>x</inf>TiO<inf>4</inf> powders: structural properties, electrical conductivity and dielectric behavior
2018, Journal of Sol-Gel Science and Technology