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The ultrafine SnO2 quantum dots (QDs) modified with poly(ethylene glycol methyl ether) (PEGME) (PEGME-SnO2 QDs) were synthesized via hydrothermal method. X-ray diffraction and high-resolution transmission electron microscopy were employed to illustrate that the PEGME-SnO2 QDs are uniform, monodispersed and about 4 nm in diameter. Then infrared spec...
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... From the literature review, it is seen that a large number of researchers groups are fully engaged in a finding of new materials like binary metallic oxides such as ZnO/CdS [6], Mo/ZnO [7] [14]. SnO2 is a transparent semiconductor with a bandgap of Eg=3.6 eV at 300 K, it has been studied more and it has excellent photoelectronic properties [15], superior gas sensitivity [16][17], high chemical stability [18][19], and unique photocatalytic activity [20]. It may be a promising candidate for use in flat-panel screens, translucent conducting electrodes, optoelectronic and other electrical devices [21]. ...
In this paper, we demonstrate the unique actinomorphic flower-like morphology of a tin oxide -zinc oxide (SZ) nanocomposite that has been synthesized using a one-step hydrothermal method and investigated for supercapacitor (SC) application. The optical, morphological and elemental composition features of pure SnO2 and SZ nanocomposite were carried out by using different characterization techniques such as XRD, FTIR, FESEM, HRTEM, and XPS. The SZ-10 nanocomposite was the most significant one and was used in the fabrication of all solid-state symmetric supercapacitor. Electrochemical analysis of the Galvano charging-discharging (GCD) curves achieved a high specific capacitance (Csp) of 797.23 Fg⁻¹ at a current density (CD) of 1 Ag⁻¹. The cyclic voltammetry (CV) curve for the SZ-10 electrode shows the high Csp of 548.56 Fg⁻¹ at a scan rate of 10 mV/s. It has superior cyclic stability with capacitance retention of 88.2% and coulombic efficiency of 98.7%, even after 5000 repetitive cycles. The SZ-10 electrode also shows a high energy density (ED) of 45.72 Whkg⁻¹ and a power density (PD) of 406 Wkg-1, at a CD of 1 Ag⁻¹. Furthermore, the fabricated SC device is linked in series to turn on a commercial red LED that glows for 1 to 2 min. These investigations demonstrate that the SZ-10 nanocomposite is an excellent electrode material for high-energy storage devices for SC applications.
... In order to improve its electrochemical or photocatalytic property, SnO 2 QDs have also successfully been bonded with some other matrix, such as TiO 2 [67,114,115], ZnO [116], MgO [117], Li 4 Ti 5 O 12 [118], SnS 2 [119], amorphous silica [120,121], conducting polymer [122,123], C 3 N 4 [124] and polyvinylpyrrolidone (PVP) [125]. ...
... Planting SnO 2 QDs onto other nanomaterials, e.g. TiO 2 [67,143], silica [121] and poly (ethylene glycol methyl ether) [123], are another efficient way to improve the photocatalytic properties on the degradation of organic pollutant. For example, Lee et al. [67] have compared the photocatalytic performances of undecorated P25 TiO 2 and the P25 TiO 2 decorated with SnO 2 QDs on the degradation toward Rhodamine B. Compared with undecorated P25 TiO 2 , the P25 TiO 2 decorated with SnO 2 QDs with size of about 5.3 nm showed an improved photocatalytic performance on the degradation of toward Rhodamine B under UV light illumination. ...
The applications of SnO2 are benefited from its nanostructure with different sizes and novel morphologies. When the size of nanoparticles reduces to 1–10 nm, the unique physical and chemical properties will make prominent. SnO2 quantum dots (QDs), a type of zero-dimensional ultrasmall SnO2 nanomaterials with a size in 1–10 nm, have displayed unique physical and chemical properties, which are different from those of their larger-sized ones. This review summarizes various synthesis strategies of SnO2 QDs and the methods of their modifications, discusses their applications in lithium-ion batteries, photocatalysis, and gas sensors. These applications profit from the characteristic properties inherent in SnO2 QDs.
... [1][2][3][4][5][6] One of the most important requirements for any photocatalyst for water splitting is that it musth ave appropriate band positions, that is, the valence band maximum (VBM) and conduction band minimum (CBM) must straddle the hydrogen evolution potential( HEP) and oxygen evolution potential( OEP). [7] Since TiO 2 was first utilized as ap hotocatalyst to split water into H 2 and O 2 in 1972, [8] many other metal oxides, such as ZnO, SnO 2 , LiTaO 3 ,A gP 3 O 4 ,N aTaO 3 ,K NbO 3 ,L iNbO 3 ,A gTaO 3 ,S rTiO 3 , Sr 2 Nb 2 O 7 ,S r 2 Ta 2 O 7 ,S bTaO 4 ,B i 12 TiO 20 , [9][10][11][12][13][14][15][16][17][18][19][20][21][22] have Bi 24 Al 2 O 39 ,h ave been found to have photocatalytic abilitiest os plit water.U nfortunately,m ost of these semiconductors can only split water by using the UV light,w hich accountsf or only 4% of solar energy and severely limits the conversione fficiencyo fp hotocatalysis. To make full use of solar energy,t he band gap of an ideal photocatalyst has to be limited to around2eV,s ot hat the photocatalyst can use visible light, which accounts for 43 %o fs olar energy. ...
Monodoping with Mo, Cr, N atoms and codoping with Mo-N, Cr-N atom pairs have been utilized to adjust the band structure of NaNbO$_{3}$ so that NaNbO$_{3}$ can effectively make use of visible light for photocatalytic decomposition of water into hydrogen and oxygen by using the hybrid density functional. It is found that the codoping is energetically favorable when compared to the corresponding monodoping due to the strong Coulomb interaction between the dopants and the other atoms, and the effective bandgap and stability for codoped systems increase with the decline of the dopant concentration and the distance between dopants. The Mo, Cr, N monodoped and Cr-N codoped systems are not suitable for photocatalytic decomposition of water by using visible light because the defects introduced by monodoping or the presence of unoccupied states above the Fermi level promoting electron-hole recombination process will suppress their photocatalytic performance. The Mo-N codoped NaNbO$_{3}$ is a promising photocatalyst for the decomposition of water by using visible light due to the fact that Mo-N codoping could reduce the bandgap to suitable value with respect to the water redox level without introducing unoccupied states.
... TiO 2 is the most extensively used photocatalyst for the treatment of organic waste but it can be activated in UV light due to its wide band gap of 3.2 eV (4,(7)(8)(9)(10). Besides TiO 2 , other photcatalysts include, for instance, ZnO, SnO 2 , and ZrO 2 , but they are also active in UV light due to their wide band gap (11)(12)(13)(14)(15)(16)(17)(18)(19). Several efforts have been made to utilize wide-band gap photocatalyst that could also be effective under visible light by doping it with some metal/non-metal or coupling with some narrow-band gap semi-conductors (4,15,(20)(21)(22)(23). ...
Ag2O nanoparticles (NPs) were synthesized using colloidal solution of spherical polyelectrolyte brushes (SPB) as nano-reactors. In this work, the average diameter of Ag2O NPs was around 10 nm as determined by transmission electron microscopy (TEM). The composite NPs of Ag2O immobilized in SPB (Ag2O-SPB) showed significant absorption in the visible light region as confirmed by UV-Vis diffuse reflectance spectra (DRS), and their photoluminescence (PL) exhibited emission peak in the visible range. Ag2O-SPB has shown outstanding photocatalytic activity during degradation of methyl blue (MB) in the visible light. This work will open up a new way to prepare ideal Ag2O nano-catalyst for the remediation of wastewater using visible light.
... Shamsizadeh and co-workers [15] efficiently removed malachite green-oxalate (MG) dye using tin oxide nanoparticles loaded activated carbon. Semiconducting SnO 2 quantum dots (QDs) are presently attracting consideration due to their noticeable effect in removing pollutants from wastewater [16]. ...
Tin dioxide (SnO2) is a material of ever increasing scientific interest as a result of its many useful and varied physical properties: it is a wide band gap (3.6 eV at 300 K), n-type semiconductor which is both highly thermally/chemically stable and inexpensively produced as a highly active nanomaterial. Consequently, it has repeatedly demonstrated promising results in a wide range of applications including gas sensing, lithium batteries and photocatalysis etc. An interesting facet of SnO2 research is the ability to tune the nanomaterials physical properties through controlled synthesis of a target morphology. By modulating the morphologies of SnO2 nanocrystals it becomes possible to prepare devices that meet new challenges, in particular by development of new ways to selectively tune morphology in order to manipulate physical properties, enhancing some and suppressing others through synthetic strategy. This review article aims to highlight the morphology- dependent properties of SnO2 nanocrystals and outlines the tools available by which to tailor applications. At the outset, general synthetic methodologies are illustrated, outlining the selective preparation of a morphologically diverse range of SnO2 nanostructures and describing the induced physical changes as a result. The impact of these different morphologies on a wide range of applications (photoluminescence, electrochemistry, photocatalysis and gas sensing) is then discussed. Finally, the promising future prospects of this research field are evaluated. The overall aim of this review is to provide an in-depth and rational understanding of the application-based properties of SnO2 nanocrystals with a primary focus on the systematic enhancement/control of the afore mentioned properties through morphological design.
The photocatalytic properties of SnO2 nanocrystals are tuned by varying their morphology and microstructure. SnO2 nanoparticles and nanowedges have been synthesized using hydrothermal methods, while microwave irradiation techniques have given nanospheres. Detailed structural and chemical characterization of these different morphologies has been accomplished. The influence of SnO2 morphology on photocatalytic activity has been examined by monitoring the degradation of aqueous methylene blue dye. Results demonstrate that changing the morphology of the SnO2 modulates both surface area and levels of surface defects and that these alterations are reflected in the photocatalytic properties of the materials. The degradation of methylene blue dye (98%) in the presence of SnO2 nanoparticles under simulated solar irradiation is superior to previously reported photocatalyst performance and is comparable to that of standard TiO2 (Degussa P-25). The SnO2 nanoparticles perform better than both the nanowedges and nanospheres and this is attributed to the number of surface defects available to the high surface area material. They also reveal outstanding recyclability and stability.
Doping technology has been proved to be a productive strategy to realize the multi-functionality of materials. Herein, Ni doped SnO 2 quantum dots (QDs) are fabricated through a convenient hydrothermal process. In the fabrication process, Vitamin C (VC) acts as a stabilizer to avoid the precipitating of Sn ⁴⁺ (Ni ²⁺ ), and Na 2 CO 3 serves as a precipitator to react with Sn ⁴⁺ (Ni ²⁺ ) to produce Ni doped SnO 2 QDs. The influence of the Ni doping amount on the photodegradation performance of SnO 2 QDs is studied. It was found that the Ni doped SnO 2 QDs with Ni/Sn atomic ratio of 1% display the best photocatalytic performace due to the following advantages: (1) the Ni doping can boost light-harvesting and narrow the band gaps of the SnO 2 QDs; (2) the SnO 2 QDs with ultra small particle size and large specific surface area can supply more reactive centers for photocatalytic reactions. The two important factors contribute to enhancing the photocatalytic performance of the 1% Ni doped SnO 2 QDs. As a result, the 1% Ni doped SnO 2 QDs photodegrade 91.5% Rhodamine B after being illuminated by solar light for 28 min, obviously surpassing that of their pure counterparts.
