Tin Dioxide鈥揅arbon Heterostructures Applied to Gas Sensing: Structure-Dependent Properties and General Sensing Mechanism

详细信息    查看全文

• 作者：Catherine Marichy ; Patricia A. Russo ; Mariangela Latino ; Jean-Philippe Tessonnier ; Marc-Georg Willinger ; Nicola Donato ; Giovanni Neri ; Nicola Pinna
• 刊名：Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：September 26, 2013
• 年：2013
• 卷：117
• 期：38
• 页码：19729-19739
• 全文大小：490K
• 年卷期：v.117,no.38(September 26, 2013)
• ISSN：1932-7455

文摘

Carbon materials such as carbon nanotubes (CNTs), graphene, and reduced graphene oxide (RGO) exhibit unique electrical properties, which are also influenced by the surrounding atmosphere. They are therefore promising sensing materials. Despite the existence of studies reporting the gas-sensing properties of metal oxide (MO_x) coated nanostructured carbon, an incomplete understanding of their sensing mechanism remains. Here we report a systematic study on the preparation, characterization, and sensing properties of CNT and RGO composites with SnO₂ coating. Atomic layer deposition (ALD) was applied to the conformal coating of the inner and outer walls of CNTs with thin films of SnO₂ of various thicknesses, while nonaqueous sol鈥揼el chemistry assisted by microwave heating was used to deposit tin dioxide onto RGO in one step. The sensing properties of SnO₂/CNTs and SnO₂/RGO heterostructures toward NO₂ target gas were investigated as a function of the morphology and density of the metal oxide coating. The general sensing mechanism of carbon-based heterostructures and the role of the various junctions involved are established.