Spontaneous Selective Deposition of Iron Oxide Nanoparticles on Graphite as Model Catalysts

Defect generation process steps.

Chathura de Alwis (Chemistry), Timothy R. Leftwich (MSE), Pinaki Mukherjee (MSE), Alex Denofrea (Chemistry) and Kathryn A. Perrine (Chemistry) published a paper titled “Spontaneous selective deposition of iron oxide nanoparticles on graphite as model catalysts” in Nanoscale Advances in 2019.

DOI: 10.1039/c9na00472f

Extract

Iron oxide nanomaterials participate in redox processes that give them ideal properties for their use as earth-abundant catalysts. Fabricating nanocatalysts for such applications requires detailed knowledge of the deposition and growth. We report the spontaneous deposition of iron oxide nanoparticles on HOPG in defect areas and on step edges from a metal precursor solution.

Various defects were created on the highly oriented pyrolytic graphite (HOPG) surface using either argon (Ar+) sputtering or a focused ion beam (FIB) to provide defects for nucleation sites. A Hitachi 2000 A FIB instrument was used to create tailored arrays of defects on HOPG using a Ga+ beam.

The sputter rate was calculated using the amount of materials removed, by recording a height profile of 1 nm using atomic force microscopy (AFM) and the time to sputter the pattern.

All the samples were imaged using a Hitachi S-4700 cold field emission high resolution field emission scanning electron microscopy (FE-SEM) instrument.

X-ray photoelectron spectroscopy (XPS) was performed using a PHI 5800 to analyze the elemental composition and oxidation state of surface species of the iron oxide nanoparticles grown on the HOPG surface.

Scanning transmission electron microscopy (STEM) imaging and energy dispersive X-ray spectroscopy (EDS) mapping were used to measure the phase and composition of iron oxide nanoparticles after annealing and to confirm if the deposition was preferential at the defect sites of graphite. A FEI Titan Themis aberration corrected scanning transmission electron microscope was used to obtain atomically resolved electron images and EDS maps of the iron oxide nanoparticles on the graphene coated TEM grid. The microscope was operated at 200 kV using a point resolution of the aberration corrected STEM mode of 0.08 nm. The microscope was equipped with a SuperX™ X-ray detector, which is composed of 4 detectors for fast X-ray mapping in STEM mode. The EDS mapping of the sample was performed on specific particles with an average beam current of 100 pA.

Acknowledgements

Equipment for obtaining the AFM images in this project was provided by NSF CHE #1725818. The electron microscopy research was performed at the Applied Chemical and Morphological Analysis Laboratory, at Michigan Technological University. The electron microscopy facility is supported by NSF MRI 1429232. We acknowledge the Michigan Tech REF-RS fund for support of this work and the David J. and Valeria Pruett Graduate Research Fellowship. We acknowledge the Applied Chemical and Morphological Analysis Laboratory (ACMAL) for staff assistance and use of facilities.

Recommended Citation

de Alwis, C., Leftwich, T., Mukherjee, P., Denofre, A., & Perrine, K. (2019). Spontaneous selective deposition of iron oxide nanoparticles on graphite as model catalysts. Nanoscale Advances, 1(12), 4729-4744.

http://doi.org/10.1039/C9NA00472F

Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/1246

Liz Miller’s schedule

Liz Miller will be out of town for 6 weeks beginning next week. Aleister and I will try to pick up the work she was doing during her absence. One area that he and I cannot assume is EBSD. We have asked someone to help us with that but the response will be slowed. So, plan your EBSD work ahead of time – don’t wait until the last minute or your work will be delayed.

Liz will return to work on April 6th.

ESEM EDS detector alarm

EDS detectors works like a thermos bottle that slow liquid nitrogen evaporation. When the vacuum in the detector deteriorates the liquid nitrogen that cools the detector evaporates quicker. That is happening in the ESEM detector. We refill the detector twice each week but depending on the timing you might hear an alarm signaling that the liquid nitrogen is low. The alarm is a beep signal every few seconds. Here is the important part of this message – if you hear the alarm let me, Aleister or Liz know so we can refill it.

I will have the vacuum replenished in the summer when ESEM use drops.

Thanks, Owen

Analytical Electron Microscopy at Nanoscale Feb. 13

Pinaki Mukherjee
Pinaki Mukherjee

ME-EM Graduate Seminar Speaker Series

proudly presents:

Pinaki Mukherjee, PhD

Michigan Technological University

Abstract: This talk presents an overview of state-of-the-art capabilities of the aberration-corrected scanning transmission electron microscope (ac-STEM) at ACMAL, Michigan Tech. The FEI Titan Themis microscope we have here is one of a kind in the whole nation in terms of capabilities. These capabilities have been developed in last two years and most of them are already available for users. We have a wide range of imaging and spectroscopic techniques that enables a user to identify elements at atomic scale (~ 0.1 nm). READ MORE

Thursday, February 13 at 4:00 p.m.

Electrical Energy Resources Center (EERC), 103
1400 Townsend Drive, Houghton, MI 49931

Annual Steam Shutdown and Power Outage

The annual steam shutdown will take place during the week following spring commencement—Sunday, May 3 – Friday, May 8 (weather permitting). This outage is required to provide maintenance and service of the boilers and steam distribution system on campus. This planned maintenance improves the reliability of our system and reduces the likelihood of an unplanned failure during the winter heating season.

There will not be heat or hot water in the affected buildings during the steam shutdown. There will be no distilled water available from the steam-driven stills. Steam-driven autoclaves/sterilizers will not be operational. 

The buildings affected will include:

  • Administration Building
  • ROTC Building
  • Academic Offices Building
  • Annex Building
  • Electrical Energy Resources
  • DOW Envir Sciences & Eng Bldg
  • Rozsa Performing Arts & Educ
  • Walker – Arts & Humanities
  • Minerals & Materials Engr Bldg
  • Grover C. Dillman Hall
  • Fisher Hall
  • J.R. Van Pelt Library
  • U.J. Noblet Forestry Building
  • Chemical Sciences & Engr Building
  • R.L. Smith (MEEM) Building
  • Student Development Complex
  • Kanwal and Ann Rekhi Hall
  • Douglass Houghton Hall
  • Memorial Union Building
  • Wadsworth Hall
  • McNair Hall
  • Central Heating Plant
  • Facilities Management
  • Hillside Place
  • Great Lakes Research Center

Facilities Management has developed a five-year rotating plan to service the 12,470-volt switchgear and associated breakers on campus. Our campus electrical distribution system depends on this gear being in good working condition. This work requires a two-night power outage that affects the least number of buildings possible. Please note that in most cases elevators, fume hoods, exhaust fans, ventilation equipment, normal lighting, plug-in appliances, and plug-in equipment will not operate during the outage.

Only items connected to the building emergency generator will have power during the outage; the building emergency generators and battery systems that supply power to emergency/egress lighting and special equipment should function as normal. If you are unsure if your equipment connects to the building emergency generator, please contact the Facilities Management Building Mechanic for your building.

Information Technology will turn off all network equipment in the affected buildings for these outages starting at 5 p.m. You should plan to save any work and shut down your computer systems and exit buildings before the outages. Additionally, some buildings with power will be without phone or internet service. Only the buildings listed will have their power shut off during the scheduled outages.

There will be two power outages.

Power Outage One: Begins at 6 p.m. Wednesday, May 6 until 6 a.m. Thursday, May 7.

Power Outage Two: Begins at 6 p.m. Thursday, May 7 until 6 a.m. Friday, May 8.

Building affected will include:

  • Rekhi
  • Dillman
  • Fisher
  • Hamar House / CDI
  • Forestry
  • M&M 
  • ME-EM
  • ROTC
  • Academic Office Building
  • Alumni House
  • Annex

Buildings with power but no phone or internet:

  • Gates Tennis Center
  • Little Huskies
  • US Forest Service Labs
  • EMS/SLS Garage

You can find more details and updates on the Facilities Management website. If there are questions or concerns with this plan, contact Energy Management or Facilities Management at 7-2303.

By Energy Management and Facilities Management.