Nanostructured TiO₂-based gas sensors with enhanced sensitivity to reducing gases

• Wojciech Maziarz,
• Anna Kusior and
• Anita Trenczek-Zajac

Beilstein J. Nanotechnol. 2016, 7, 1718–1726, doi:10.3762/bjnano.7.164

• . Mickiewicza 30, Krakow 30-059, Poland 10.3762/bjnano.7.164 Abstract 2D TiO2 thin films and 3D flower-like TiO2-based nanostructures, also decorated with SnO2, were prepared by chemical and thermal oxidation of Ti substrates, respectively. The crystal structure, morphology and gas sensing properties of the

• selectivity to CO(CH3)2 after sensitization by SnO2 nanoparticles. The sensor response time was of the order of several seconds. Their fast response, high sensitivity to selected gas species, improved selectivity and stability suggest that the SnO2-decorated flower-like 3D nanostructures are a promising

• importance to consciously design the method of preparation. Another way to improve sensing properties is the combination of two dissimilar materials [32]. For the past few decades, the TiO2/SnO2 coupled system has been a subject of intensive research [18][27][33]. This synergetic system modifies the

Ammonia gas sensors based on In₂O₃/PANI hetero-nanofibers operating at room temperature

• Qingxin Nie,
• Zengyuan Pang,
• Hangyi Lu,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2016, 7, 1312–1321, doi:10.3762/bjnano.7.122

• even death [5][6][7]. So, there is an urgent need to develop a kind of gas sensor with high sensitivity and selectivity to detect NH3 at room temperature. Metal oxide semiconductors can be applied as sensing materials for monitoring NH3. Ammonia sensors based on In2O3 [8], TiO2 [9], SnO2 [10], ZnO [11

Photocurrent generation in carbon nanotube/cubic-phase HfO₂ nanoparticle hybrid nanocomposites

• Protima Rauwel,
• Augustinas Galeckas,
• Martin Salumaa,
• Frédérique Ducroquet and
• Erwan Rauwel

Beilstein J. Nanotechnol. 2016, 7, 1075–1085, doi:10.3762/bjnano.7.101

• conduction via the CNT. To date, numerous studies have been reported on the decoration of CNTs with metal oxides including TiO2 [7][8] and ZnO [9] for solar cell applications and SnO2 for gas sensors. Reports on the fabrication of an all carbon nanocomposite combining CNTs, graphene and carbon quantum dots

NO gas sensing at room temperature using single titanium oxide nanodot sensors created by atomic force microscopy nanolithography

• Li-Yang Hong and
• Heh-Nan Lin

Beilstein J. Nanotechnol. 2016, 7, 1044–1051, doi:10.3762/bjnano.7.97

• fabrication of titanium oxide nanowire (NW) gas sensors [25][26]. NO gas sensing at low concentrations is beneficial for human health [1][2] and environmental monitoring [3]. Various types of metal oxide nanomaterials have been utilized for NO or NO2 gas sensing, e.g., SnO2 [12][15][16][17], ZnO [13][14][17

Evaluation of gas-sensing properties of ZnO nanostructures electrochemically doped with Au nanophases

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2016, 7, 22–31, doi:10.3762/bjnano.7.3

• . In this context, chemical gas sensors have a deep impact on human security, medical prevention and diagnosis, monitoring and detection of polluting and toxic substances [1]. Specifically, nowadays metal oxide semiconductors (MOS), such as WO3, SnO2, In2O3 and TiO2 [2], have been largely used as

Effects of swift heavy ion irradiation on structural, optical and photocatalytic properties of ZnO–CuO nanocomposites prepared by carbothermal evaporation method

• Sini Kuriakose,
• D. K. Avasthi and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2015, 6, 928–937, doi:10.3762/bjnano.6.96

• ], vapour-transport processes [2][3], thermal evaporation [4], wet chemical methods [5] and flame-transport methods [6][7] have been used to fabricate nanocomposites of SnO2–ZnO [8], ZnO–ZnS [9], and Zn–ZnO [10]. ZnO, an n-type semiconductor, has attracted significant research interests due to its wide band

Tunable white light emission by variation of composition and defects of electrospun Al₂O₃–SiO₂ nanofibers

• Jinyuan Zhou,
• Gengzhi Sun,
• Hao Zhao,
• Xiaojun Pan,
• Zhenxing Zhang,
• Yujun Fu,
• Yanzhe Mao and
• Erqing Xie

Beilstein J. Nanotechnol. 2015, 6, 313–320, doi:10.3762/bjnano.6.29

• preparation processes, which can be effectively tuned and controlled by doping [1][2][3][4]. Thus far, in order to achieve enhanced and stable light emission, various materials have been incorporated into a SiO2 matrix, such as Si nanocrystals, carbon nanocomposites, ZnO, Al2O3, SnO2, and various rare-earth

Influence of stabilising agents and pH on the size of SnO₂ nanoparticles

• Olga Rac,
• Patrycja Suchorska-Woźniak,
• Marta Fiedot and
• Helena Teterycz

Beilstein J. Nanotechnol. 2014, 5, 2192–2201, doi:10.3762/bjnano.5.228

• material increases the selectivity and sensitivity and shortens the response time of a sensor. However, the synthesis of SnO2 nanoparticles presents many difficulties. The following article presents a simple and inexpensive method for the synthesis of SnO2 nanoparticles. The influence of the surfactant and

• polymer choice on the size of the resulting nanoparticles was investigated and a mechanism describing their interaction was proposed. It was found that stable colloids of SnO2 nanoparticles are formed in the presence of both PEI and Triton X-100 surfactants as stabilising agents. However, an additional

• dioxide; Introduction Tin dioxide is an n-type semiconductor with a band gap width of 3.6 eV. It is characterised by good photocatalytic properties and in its presence, decomposition of an organic dye in the visible range of the electromagnetic spectrum may takes place [1]. Moreover, SnO2 is widely used

Room temperature, ppb-level NO₂ gas sensing of multiple-networked ZnSe nanowire sensors under UV illumination

• Sunghoon Park,
• Soohyun Kim,
• Wan In Lee,
• Kyoung-Kook Kim and
• Chongmu Lee

Beilstein J. Nanotechnol. 2014, 5, 1836–1841, doi:10.3762/bjnano.5.194

• at room temperature in the dark in this study was stronger than or comparable to those of typical metal oxide, 1D nanostructures, such as ZnO, SnO2, In2O3, and MoO3 at higher temperatures and higher NO2 concentrations [25][26][27][28][29][30]. This suggests that the ZnSe nanowires are also a

• or comparable to those of typical metal oxide semiconductors reported in the literature, such as ZnO, SnO2, In2O3, and MoO3, at higher temperatures and higher NO2 concentrations. The ZnSe nanowire sensors cannot be used at high temperatures, such as 300 °C, because of the oxidation of ZnSe, but their

Nanocrystalline ceria coatings on solid oxide fuel cell anodes: the role of organic surfactant pretreatments on coating microstructures and sulfur tolerance

• Chieh-Chun Wu,
• Ling Tang and
• Mark R. De Guire

Beilstein J. Nanotechnol. 2014, 5, 1712–1724, doi:10.3762/bjnano.5.181

• –GDC composite). In previous studies of oxide film deposition on surfactant-treated surfaces, sulfonate surfaces strongly favored the formation of continuous films of ZrO2, TiO2, and SnO2 [26]. This outcome is attributed to the high negative surface charge density of well-packed sulfonate surfaces

Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

• Anastasios Stergiou,
• Georgia Pagona and
• Nikos Tagmatarchis

Beilstein J. Nanotechnol. 2014, 5, 1580–1589, doi:10.3762/bjnano.5.170

• . This configuration allows for photocurrent measurements under electrochemical bias. Electrophoretic deposition is applied to fabricate films of the graphene-based hybrid material onto an optically transparent electrode (OTE) covered with nanostructured SnO2. Typically, a suspension of the graphene

• /SnO2/graphene-based hybrid material) is deposited within a short period of time. The photocurrent action spectrum of the OTE/SnO2/graphene-based hybrid material electrode is evaluated by examining the wavelength dependence of the incident-photon-to-current conversion efficiency (IPCE). The IPCE values

• state to the graphene sheets occurs. Moving a step forward, a prototype photoelectrochemical device, in which a SnO2 electrode was coated with the aforementioned graphene–porphyrin hybrid material, was constructed. Photophysical and electrical measurements revealed the absence of any photocurrent

Microstructural and plasmonic modifications in Ag–TiO₂ and Au–TiO₂ nanocomposites through ion beam irradiation

• Venkata Sai Kiran Chakravadhanula,
• Yogendra Kumar Mishra,
• Venkata Girish Kotnur,
• Devesh Kumar Avasthi,
• Thomas Strunskus,
• Vladimir Zaporotchenko,
• Dietmar Fink,
• Lorenz Kienle and
• Franz Faupel

Beilstein J. Nanotechnol. 2014, 5, 1419–1431, doi:10.3762/bjnano.5.154

• semiconducting matrices, such as SnO2 [10], ZnO [11] and CdS [12] for the embedding of noble metal nanoparticles has shown great potential. Thin films and nanostructures of TiO2 are probably one of the most investigated systems for different applications, such as memristors, dye-sensitized solar cells

Liquid fuel cells

• Grigorii L. Soloveichik

Beilstein J. Nanotechnol. 2014, 5, 1399–1418, doi:10.3762/bjnano.5.153

• achieved with Ptn(SnO2)/C (n = 1, 3, 9) electrocatalysts. A fuel cell using 2 M EtOH, a Nafion® 117 membrane and a Pt/C cathode catalyst reached a peak power density of 127 mW/cm2 for n = 3 at 100 °C [69]. Acetaldehyde and acetic acid were the major products, and the yield of CO2 was below 7%. Acetic acid

DFT study of binding and electron transfer from colorless aromatic pollutants to a TiO₂ nanocluster: Application to photocatalytic degradation under visible light irradiation

• Corneliu I. Oprea,
• Petre Panait and
• Mihai A. Gîrţu

Beilstein J. Nanotechnol. 2014, 5, 1016–1030, doi:10.3762/bjnano.5.115

• conduction band of TiO2, due to its d-symmetry, but not that of SnO2 or ZnO, which have predominantly s-character. Keeping in mind that for Grätzel cells the charge transfer is optimized in the case of a strong overlap between the dye and the semiconductor [18], which is favored by the presence of charge on

One-step synthesis of high quality kesterite Cu₂ZnSnS₄ nanocrystals – a hydrothermal approach

• Vincent Tiing Tiong,
• John Bell and
• Hongxia Wang

Beilstein J. Nanotechnol. 2014, 5, 438–446, doi:10.3762/bjnano.5.51

• attributed to SnO2 (JCPDS 00-001-0625) impurity. Raman spectra in Figure 3b indicates that, in the absence of TGA, a weak peak located at 298 cm−1 which is assigned to ternary Cu2SnS3, is detected along with the CZTS peaks. However, the peaks corresponding to impurities disappear when tiny amount of TGA (18

• poor composition in the sample with no TGA is probably due to the formation of Cu2SnS3 and SnO2 impurity as confirmed by the above XRD and Raman spectrum. The EDS analysis also shows that the elemental composition of the CZTS material using excessive amount of TGA (180 μL) leads to the slightly reduced

Quantum size effects in TiO₂ thin films grown by atomic layer deposition

• Massimo Tallarida,
• Chittaranjan Das and
• Dieter Schmeisser

Beilstein J. Nanotechnol. 2014, 5, 77–82, doi:10.3762/bjnano.5.7

• nm thickness and allows for the investigation of similar quantum size effects in TiO2 thin films. In this case interface effects, as those observed in TiO2 ALD films grown on SnO2:F [11], could also become important. We performed the characterization of ALD films by using mostly X-ray absorption

• by Kronawitter et al. [11] at the interface between TiO2 and SnO2:F and were attributed to modified electronic properties of TiO2. In that case, TiO2 was grown by ALD using TiCl4 and H2O at 150 °C. This shows that the interface formation is similar for these two different ALD-precursors and for

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• built-in potential on the DSC performance at the TiO2/SnO2:F interface, investigated on a nanometer scale by KPFM measurements under visible light illumination, has not been resolved so far. Keywords: atomic force microscopy (AFM); dye-sensitized solar cells (DSC); Kelvin probe force microscopy (KPFM

• electrons diffuse toward the SnO2:F substrate and establish the photovoltage. The most frequently used dye complexes contain less-abundant transition metal elements such as ruthenium. Complexes of earth-abundant metals such as zinc and copper are candidates to replace the more expensive ruthenium dyes [9

• reached by the incident light [19]. In the present work, the sample was illuminated with focused light from an optical fiber or directly with a laser. The measured SPV can have two contributions, one from the TiO2/SnO2:F interface and the other from the TiO2 layer depending on the energy of the incident

Photoelectrochemical and Raman characterization of In₂O₃ mesoporous films sensitized by CdS nanoparticles

• Mikalai V. Malashchonak,
• Sergey K. Poznyak,
• Eugene A. Streltsov,
• Anatoly I. Kulak,
• Olga V. Korolik and
• Alexander V. Mazanik

Beilstein J. Nanotechnol. 2013, 4, 255–261, doi:10.3762/bjnano.4.27

• , Ag2S, Bi2S3 and others) immobilized onto the surface of mesoporous films of wide-bandgap oxides (TiO2, ZnO, SnO2, Nb2O5, Ta2O5, WO3, In2O3) are used as the sensitizing components [2][3][4][5]. It is considered that the best technique for the in situ deposition of such nanoparticles is the successive

Nanostructure-directed chemical sensing: The IHSAB principle and the dynamics of acid/base-interface interaction

• James L. Gole and
• William Laminack

Beilstein J. Nanotechnol. 2013, 4, 20–31, doi:10.3762/bjnano.4.3

• gas and metal oxides. The dynamic interaction of NO with TiO2, SnO2, NiO, CuxO, and AuxO (x >> 1), in order of decreasing acidity, demonstrates this effect. Interactions with the metal-oxide-decorated interface can be modified by the in situ nitridation of the oxide nanoparticles, enhancing the

• broader-based and predicts reversible sensor–analyte interactions. The fractional deposition of TiO2, SnO2, NiO, CuxO, and AuxO (x >> 1) nanostructured islands (Figure 1) modifies the sensitivity response of the extrinsic porous silicon interface. The deposited nanostructures, in effect, dominate the PS

• decorated surface is five times more responsive than the untreated PS interface [24]. For p+-type PS, TiO2, SnO2, CuxO, and AuxO decorated surfaces are respectively ≥ 4, 2.5, 3–3.5, and 7 times more responsive. The analyte response data forms the basis for the development of the materials positioning

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• should be pointed out that the SSD technique is not limited to the deposition of titanium dioxide and was utilized for patterned growth of other oxides such as In2O3 [70], Ta2O5, SnO2 and SrTiO3 [69]. The most popular means for selective growth is direct site-selective deposition (Figure 4), based on

Extended X-ray absorption fine structure of bimetallic nanoparticles

• Carolin Antoniak

Beilstein J. Nanotechnol. 2011, 2, 237–251, doi:10.3762/bjnano.2.28

• several examples can be found for EXAFS analysis on nanoparticle systems, e.g., Co [8], CdS [9], CdSe [10], SnO2 [11] and Au [12] nanoparticles, as well as Ag nanoparticles embedded in glass [13][14]. To discuss the advantages and possible drawbacks of EXAFS analysis in nanoparticulate systems, this paper

Schottky junction/ohmic contact behavior of a nanoporous TiO₂ thin film photoanode in contact with redox electrolyte solutions

• Masao Kaneko,
• Hirohito Ueno and
• Junichi Nemoto

Beilstein J. Nanotechnol. 2011, 2, 127–134, doi:10.3762/bjnano.2.15

• are transported first to the fluorine-doped tin oxide (FTO, SnO2:F) conductive layer through TiO2 grain boundaries and then to the cathode reducing electron acceptor there (O2 in the present case). In a Schottky junction, under the conditions when the band structure is flat without any bending, the

• To prepare a nanoporous TiO2 film, Ti-nanoxide paste (T/SP, average particle size 13 nm, anatase >90%) was purchased from Solaronix SA, Aubonne, Switzerland. Larger size TiO2 powders, G2 (500 nm, rutile >95%) was purchased from Showa Denko Co., Ltd, Japan. F-doped SnO2 conductive glass (FTO, surface

Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition

• Mario Boehme,
• Emanuel Ionescu,
• Ganhua Fu and
• Wolfgang Ensinger

Beilstein J. Nanotechnol. 2011, 2, 119–126, doi:10.3762/bjnano.2.14

• surfaces of substrates or homogeneous nucleation in solution, is determined by the supersaturated solution [16]. When the solution is supersaturated, nucleation begins; ITO nanocrystallites form on the template surface (Equation 12), according to the concentration ratio of In2O3 and SnO2, due to the