Environmental Nanogeochemistry Group

Research Focus

In our research, we study the key mechanistic processes by which metal ions interact with mineral-water interfaces and use this understanding to better predict reactivity in the field.

Variation in field and laboratory measurements likely arise in part from the complexity of mineral-water interfaces. Key differences in the interfacial region as compared to that of a bulk solid or liquid include:

  1. Undercoordination of surface atoms as compared to bulk atoms
  2. Interfacial water is structured differently than bulk water
  3. Solution phase ions can change surface functional groups and surface functional groups can in turn promote or impede how solution phase ions interact with the surface
Developing a true mechanistic understanding of how metal ions interact with surfaces requires addressing both the complexity of both the mineral surface and the near surface solution phase, which we address through the following research questions: 1) To what extent do metal ions adsorb to defects? 2) How do the presence of other ions/ligands affect metal uptake? and 3) To what extent do environmental conditions, especially temperature, affect uptake?


We are always looking for motivated undergraduate students to join our lab group! We are also currently recruiting a PhD student. See the Join Us tab for more details.

Jacquelyn Bracco

Assistant Professor
Alysse and Helmut Heydegger Endowed Chair in Environmental Geochemistry
School of Earth and Environmental Sciences
Queens College, City University of New York (CUNY)

Education and Experience

  • Postdoctoral Researcher, Argonne National Laboratory
  • PhD, Environmental Sciences, Wright State University
  • M.S., Earth and Atmospheric Sciences, Georgia Tech
  • B.S., Earth and Atmospheric Sciences, Georgia Tech



This endowment was made possible through the generosity of Dr. H. Roland Heydegger ’56 and Ms. Carol Bruell

Inva Braha
MA Geological and Environmental Sciences student
Thesis Project: Defect Driven Pb Adsorption at the Mineral-Water Interface

Amanda Dorfman
BS Geology Student
Project: Pb Adsorption to the Barite (210) - Water Interface

Lexi Kenis
BS Geology student
Project: Sr Adsorption to the Barite (210) - Water Interface

Tuffani Taigeshwar
BS Geology student
Project: Strontium Incorporation into Calcite: A Thermodynamic or Kinetic Effect?

Gusnadi Tjong
BS Environmental Sciences student
Project: Strontium Incorporation into Calcite: A Thermodynamic or Kinetic Effect?

Bracco, JN; Lee, SS; Stubbs, JE; Eng, PE; Jindra, S; Warren, DM; Kommu, A; Fenter, P; Kubicki, JD; Stack, AG. Simultaneous Adsorption and Incorporation of Sr2+ at the Barite (001) – Water Interface. Journal of Physical Chemistry C, 123, 2019, 1194-1207.

Yuan, K; Bracco, JN; Schmidt, M; Soderholm, L; Fenter, P; Lee, SS. Effect of Anions on the Changes in the Structure and Adsorption Mechanism of Zirconium Species at the Muscovite (001) – Water Interface. Journal of Physical Chemistry C, 123, 2019, 16699-16710.

Weber, J; Bracco, JN; Poplawsky, JD; Ievlev, AV; More, KL; Lorenz, M; Bertagni, AL; Jindra, SA; Starchenko, V; Higgins, SR; Stack, AG. Unraveling the Effects of Strontium Incorporation on Barite Growth—In Situ and Ex Situ Observations Using Multiscale Chemical Imaging. Cryst. Growth Des., 18, 2018, 5521-5533.

Jindra, SA; Bertagni, A; Bracco, JN; Higgins, SR. Hydrothermal Atomic Force Microscopy Investigation of Barite Growth: The Role of Spectator Ions in Elementary Step Edge Growth Kinetics and Hillock Morphology. Cryst. Growth Des., 17, 2018, 6085-6095.

Bracco, JN; Lee, SS; Stubbs, JE; Eng, PJ; Heberling, F; Fenter, P; Stack, AG. Hydration Structure of the Barite (001)-Water Interface: Comparison of X-ray Reflectivity with Molecular Dynamics Simulations. Journal of Physical Chemistry C, 121, 2017, 12236- 12248.

Bracco, JN; Gooijer, Y.; Higgins, SR. Hydrothermal atomic force microscopy observations of barite step growth rates as a function of the aqueous barium-to-sulfate ratio. Geochim. Cosmochim. Acta 2016, 183, 1-13.

Bracco, JN; Gooijer, Y.; Higgins, SR. Growth kinetics of step edges on celestite (001) surfaces as a function of temperature, saturation state, ionic strength, and aqueous strontium:sulfate ratio: An in situ atomic force microscopy study. Geochim. Cosmochim. Acta 2016, 175, 222-238.

Bracco, JN; Stack, AG; Higgins, SR. Magnesite step growth rates as a function of the aqueous magnesium:carbonate ratio. Cryst. Growth Des. 2014, 14, 6033-6040.

Bracco, JN; Stack, AG; Steefel, CI. Upscaling calcite growth rates from the meso- to the macro- scale. Environ. Sci. Technol. 2013, 47, 7555-7562.

Bracco, JN; Grantham, MC; Stack, AG. Calcite growth rates as a function of aqueous calcium-to-carbonate ratio, saturation index, and inhibitor concentration: insight into the mechanism of reaction and poisoning by strontium. Cryst. Growth Des. 2012, 12, 3540-3548.

Fall 2019

  • GEOL 09: Environmental Issues
    The scientific background for some major environmental issues is introduced. These issues may include the availability and use of renewable and non-renewable resources; conservation, recycling, waste disposal, and pollution; and land use. Human impact on global environmental problems are examined from both scientific and social points of view.

Spring 2019

  • GEOL 766: Analytical Techniques in Environemtnal Geosciences
    A graduate level course on analytical techniques applied to geochemical problems. Primarily lab and field based.
  • GEOL 099: Planet Earth: Resources (and Hazards) for the 21st Century
    An introduction to how understanding Earth's composition and processes enables geologists to find the energy and mineral resources on which modern civilization is based, and why those processes can lead to natural disasters if not fully understood.

Fall 2018

  • GEOL 760: Environmental Geochemistry
    A graduate level course on thermodynamic and kinetic principles applied to geochemical problems.

Undergraduate Opportunities

Never done research before? No problem! Most of the students working in our lab group have limited research experience - we will train you!

Have taken one undergraduate chemistry course and one 200 level geology course (mineralogy preferred) or ENSCI 200.

PhD Student Opportunity

I am looking for a PhD student to start in the fall of 2020 to work on a project studying the role that defects on mineral surfaces play in ion adsorption. This project is in collaboration with many other researchers, including researchers at Oak Ridge National Laboratory and Argonne National Laboratory. Required travel to the Advanced Photon Source or National Synchrotron Light Source II roughly twice per year.

Geochemistry or mineralogy background required, preference for students with familiarity with either coding or synchrotron x-ray scattering techniques.

Please send contact information, cv, and a brief description of your research interests to Jacquelyn.Bracco@qc.cuny.edu

More details on the PhD program are available here (applications due December 15, 2019)

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