About

Robert Vajtai is a Research Professor at Rice University, with a background in physics and solid-state physics. He received his undergraduate and doctoral degrees from the University of Szeged in Hungary, earning his Ph.D. in 1997. His research focuses on the synthesis, processing, and characterization of new, advanced material forms and structures, particularly nanometals, nanosized oxides, and various forms of nanocarbon such as carbon nanotubes and graphene. His work includes developing applications of nanomaterials for energy storage devices, multifunctional vehicle parts, sensors, and thermal management systems. Vajtai has a distinguished academic and research career, having been a tenured faculty member in the Department of Experimental Physics in Hungary, and holding fellowships at institutions such as the Swedish Institute in Uppsala, EPFL in Lausanne, and the Max Planck Institute in Göttingen. Before joining Rice University in 2008, he spent eight years at Rensselaer Polytechnic Institute, where he managed laboratories focused on nanoparticle generation and carbon nanotechnology. He has authored over 150 scientific publications, including articles in prominent journals like Science, Nature, and PNAS, and has been cited more than five thousand times. Vajtai is also active in the scientific community, organizing conferences, editing journals, reviewing proposals, and recently editing the Springer Handbook of Nanomaterials. He is passionate about teaching, having instructed courses in physics, thermodynamics, electrodynamics, materials science, and solid-state physics, and has received recognition for mentoring high-school and undergraduate research.

Research topics

• Chemistry
• Optoelectronics
• Organic chemistry
• Computer Science
• Nanotechnology
• Materials science
• Computational chemistry
• Embedded system
• Crystallography
• Optics
• Physics

Selected publications

• The modulating effect of N coordination on single-atom catalysts researched by Pt-N -C model through both experimental study and DFT simulation

  Journal of Material Science and Technology · 2021 · 48 citations

  • Computer Science
  • Chemistry
  • Computational chemistry
  DOI

• Facile synthesis of highly fluorescent free-standing films comprising graphitic carbon nitride (g-C₃N₄) nanolayers

  New Journal of Chemistry · 2020 · 58 citations

  • Chemistry
  • Nanotechnology
  • Optoelectronics

  The free-standing g-C₃N₄ films were fabricated by thermal condensation of C₂H₄N₄ at 600 °C in a low pressure of Ar atmosphere. The as-synthesized g-C₃N₄ films exhibited stable and strong photoluminescence emission centered around 455–460 nm.

  DOI

• Multifunctional Bio‐Nanocomposite Coatings for Perishable Fruits

  Advanced Materials · 2020 · 270 citations

  • Materials science
  • Waste management
  • Nanotechnology

  Hunger and chronic undernourishment impact over 800 million people, which translates to ≈10.7% of the world's population. While countries are increasingly making efforts to reduce poverty and hunger by pursuing sustainable energy and agricultural practices, a third of the food produced around the globe still is wasted and never consumed. Reducing food shortages is vital in this effort and is often addressed by the development of genetically modified produce or chemical additives and inedible coatings, which create additional health and environmental concerns. Herein, a multifunctional bio-nanocomposite comprised largely of egg-derived polymers and cellulose nanomaterials as a conformal coating onto fresh produce that slows down food decay by retarding ripening, dehydration, and microbial invasion is reported. The coating is edible, washable, and made from readily available inexpensive or waste materials, which makes it a promising economic alternative to commercially available fruit coatings and a solution to combat food wastage that is rampant in the world.

  DOI

• Full-color fluorescent carbon quantum dots

  Science Advances · 2020 · 616 citations

  • Optoelectronics
  • Materials science
  • Photochemistry

  Quantum dots have innate advantages as the key component of optoelectronic devices. For white light-emitting diodes (WLEDs), the modulation of the spectrum and color of the device often involves various quantum dots of different emission wavelengths. Here, we fabricate a series of carbon quantum dots (CQDs) through a scalable acid reagent engineering strategy. The growing electron-withdrawing groups on the surface of CQDs that originated from acid reagents boost their photoluminescence wavelength red shift and raise their particle sizes, elucidating the quantum size effect. These CQDs emit bright and remarkably stable full-color fluorescence ranging from blue to red light and even white light. Full-color emissive polymer films and all types of high-color rendering index WLEDs are synthesized by mixing multiple kinds of CQDs in appropriate ratios. The universal electron-donating/withdrawing group engineering approach for synthesizing tunable emissive CQDs will facilitate the progress of carbon-based luminescent materials for manufacturing forward-looking films and devices.

  DOI

• White luminescent single-crystalline chlorinated graphene quantum dots

  Nanoscale Horizons · 2020 · 65 citations

  • Materials science
  • Nanotechnology
  • Optoelectronics

  A new class of white luminescent materials, white-light-emitting graphene quantum dots (WGQDs), have attracted increasing attention because of their unique features and potential applications. Herein, we designed and synthesized a novel WGQDs via a solvothermal molecular fusion strategy. The modulation of chlorine doping amount and reaction temperature gives the WGQDs a single-crystalline structure and bright white fluorescence properties. In particular, the WGQDs also exhibit novel and robust white phosphorescence performance for the first time. An optimum fluorescence quantum yield of WGQDs is 34%, which exceeds the majority of reported WGQDs and other white luminescent materials. The WGQDs display broad-spectrum absorption within almost the entire visible light region, broad full width at half maximum and extend their phosphorescence emission to the entire white long-wavelength region. This unique dual-mode optical characteristic of the WGQDs originates from the synergistic effect of low-defect and high chlorine-doping in WGQDs and enlarges their applications in white light emission devices, cell nuclei imaging, and information encryption. Our finding provides us an opportunity to design and construct more advanced multifunctional white luminescent materials based on metal-free carbon nanomaterials.

  DOI

Frequent coauthors

• Pulickel M. Ajayan

  Rice University

  14 shared

• Anand B. Puthirath

  Rice University

  8 shared

• Sreehari K. Saju

  Rice University

  5 shared

• Ranjith Prasannachandran

  Indian Institute of Science Education and Research Thiruvananthapuram

  4 shared

• Yang Li

  Guangxi Medical University

  3 shared

• Tony Ivanov

  DEVCOM Army Research Laboratory

  3 shared

• Abhijit Baburaj

  Rice University

  3 shared

• A. Glen Birdwell

  DEVCOM Army Research Laboratory

  3 shared

Awards & honors

• Bolyai Fellowship of the Hungarian Academy of Sciences (1999…
• Siemens-Westinghouse Mentoring Award

Similar researchers at Rice University

• Menachem Elimelechh-209
• Pulickel Ajayanh-204
• James Tourh-178
• Naomi J. Halash-173
• Frank Geurtsh-157