In₂O₃ Nanoparticles Decorated ZnO Hierarchical Structures for n-Butanol Sensor

Abstract

In2O3 nanoparticles decorated ZnO hierarchical structures with excellent n-butanol-sensing performance were successfully fabricated by the one-pot sol–gel method. The formation process of the unique In2O3–ZnO hierarchical structure was investigated through experiments. The addition of indium was a crucial factor for the morphology and structure of the final product. The influence of the addition of indium on the sensor properties of the In2O3–ZnO hierarchical structure was examined systematically. The optimum indium–zinc ratio was 1:3. Sensor responses of the In2O3–ZnO (1:3) heterostructures toward 10 and 100 ppm n-butanol reached 18 and 218.3 at 260 °C. The response–recovery times toward 10 ppm n-butanol were 1 and 5 s. The gas-sensing mechanism was investigated based on the X-ray photoelectronic spectroscopy, photoluminescence spectroscopy, electron paramagnetic resonance spectroscopy, and UV–vis diffuser reflectance spectroscopy analyses. The improved gas-sensing performance of In2O3–ZnO was ascribed mainly to the unique microstructure and the surface decoration by In2O3 nanoparticles.

Inorganic-Diverse Nanostructured Materials for Volatile Organic Compound Sensing

“…The sensors responses of these materials are 23.512 and 714, correspondingly, with response/recovery time <1 min/7 min, as shown in Table 2 . In a similar trend, hierarchical In 2 O 3 NPs decorated ZnO nanostructure [ 224 ] displayed discrimination of n-butanol (R a /R g = 218.3 for 100 ppm at 260 °C; response/recovery time = 22 s/53 s) with a LOD down to sub-ppm level, thereby become a notable material. Apart from hierarchical nanostructures, diverse shaped nanostructures were also used in volatile alcohols identification.…”

Indium Oxide Based Nanomaterials: Fabrication Strategies, Properties, Applications, Challenges and Future Prospect

“…Generally, this method involves controlled hydrolysis of metal alkoxides like zirconium propoxide or metal salts such as metal nitrates or chlorides in an aqueous or organic solvent medium. It is to be noted that at the initial step of this method the hydrolysis and polycondensation reactions occur that lead to the generation of polymeric/colloidal sol with particles of nano dimension [5,18]. By increasing mass of the desired material into sol or other significant changes in sol like solvent substitution, pH variation, solvent evaporation, etc.…”

“…results the formation of gel with three-dimensional network of porous nature. The solvent is enclosed inside the porous gel structure [5,18]. Heat treatment of the gel structure produces dense ceramics.…”

“…In order to minimize the cost without sacrificing the functional properties, indium oxide based thin films have been fabricated [15][16][17]. In this respect, the formation of heterostructure with band gap engineering of IO or IO based nanomaterials improve its functional properties for advanced applications especially in transparent electronic devices and sensors [18][19][20]. In this regard, Wang et al [18] reported hierarchically structured ZnO decorated with IO nanoparticles synthesized by one-pot sol-gel process towards improvement in n-butanol sensing performance.…”

“…In this respect, the formation of heterostructure with band gap engineering of IO or IO based nanomaterials improve its functional properties for advanced applications especially in transparent electronic devices and sensors [18][19][20]. In this regard, Wang et al [18] reported hierarchically structured ZnO decorated with IO nanoparticles synthesized by one-pot sol-gel process towards improvement in n-butanol sensing performance. Moreover, N-doped graphene quantum dots modified three-dimensional ordered macroporous IO based nanocomposites had been fabricated for NO 2 gas sensing application [10].…”