ACS Applied Materials & Interfaces
ACS Applied Materials & Interfaces
5 years ago

Localized Charge Transfer in Two-Dimensional Molybdenum Trioxide

Localized Charge Transfer in Two-Dimensional Molybdenum Trioxide
Pooi See Lee, Liang Liu, Viet Cuong Nguyen, Kaushik Parida, Venkateswarlu Bhavanasi, Vipin Kumar, Daniel Mandler
Molybdenum trioxide is an interesting inorganic system in which the empty 4d states have potential to hold extra electrons and therefore can change states from insulating opaque (MoO3) to colored semimetallic (HxMoO3). Here, we characterize the local electrogeneration and charge transfer of the synthetic layered two-dimensional 2D MoO3-II (a polymorph of MoO3 and analogous to α-MoO3) in response to two different redox couples, i.e., [Ru(NH3)6]3+ and [Fe(CN)6]3– by scanning electrochemical microscopy (SECM). We identify the reduction of [Ru(NH3)6]3+ to [Ru(NH3)6]2+ at the microelectrode that leads to the reduction of MoO3-II to conducting blue-colored molybdenum bronze HxMoO3. It is recognized that the dominant conduction of the charges occurred preferentially at the edges active sites of the sheets, as edges of the sheets are found to be more conducting. This yields positive feedback current when approaching the microelectrode toward 2D MoO3-II-coated electrode. In contrast, the [Fe(CN)6]4–, which is reduced from [Fe(CN)6]3–, is found unfavorable to reduce MoO3-II due to its higher redox potential, thus showing a negative feedback current. The charge transfer on MoO3-II is further studied as a function of applied potential. The results shed light on the charge transfer behavior on the surface of MoO3-II coatings and opens the possibility of locally tuning of their oxidation states.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b09641

DOI: 10.1021/acsami.7b09641

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.