A More Efficient, Safer Alternative to Sourcing Copper

Copper stays among the single most common metals in daily life. As a conductor of heat and electrical energy, it is used in wires, roof, and pipes, along with a driver for petrochemical plants, solar and electrical conductors, and for a vast array of energy-related applications. Subsequently, any technique to collect more of the important product shows a useful venture.

Debora Rodrigues, Ezekiel Cullen Professor of Engineering at the University of Houston Cullen College of Engineering, in partnership with Francisco C. Robles Hernandez, teacher at the UH College of Technology and Ellen Aquino Perpetuo, teacher at the University of Sao Paulo, Brazil provided definitive research study for comprehending how germs discovered in copper mines transform poisonous copper ions to steady single-atom copper.

Ezekiel Cullen Professor of Engineering at the University of Houston Cullen College of Engineering. Credit: University of Houston

In their co-authored paper, “Copper Mining Bacteria: Converting toxic copper ions into a stable single atom copper,” their research study shows how copper-resistant germs from a copper mine in Brazil transform CuSO₄ (copper sulfate) ions into zero-valent Cu (metal copper).

“The idea of having bacteria in mines is not new, but the unanswered question was: what are they doing in the mines?” Robles stated. “By putting the bacteria inside an electronic microscope, we were able to figure out the physics and analyze it. We found out the bacteria were isolating single atom copper. In terms of chemistry, this is extremely difficult to derive. Typically, harsh chemicals are used in order to produce single atoms of any element. This bacterium is creating it naturally that is very impressive.”

As beneficial as copper is, the procedure of mining the metal typically causes poisonous direct exposures and difficulties on extracting considerable volume for industrial usage. Approximately one billion lots of copper are approximated in worldwide reserves, according to the Copper Development Association Inc., with approximately 12.5 million metric loads annually mined. This aggregates to approximately 65 years of staying reserves. Part of the supply difficulty originates from restricted offered copper in high concentration in the earth’s crust, however the other difficulty is the direct exposure to sulfur dioxide and nitrogen dioxide in the copper smelting and production procedure to focus the metal into beneficial amounts.

Francisco C. Robles, teacher at the UH College of Technology. Credit: University of Houston

“The novelty of this discovery is that microbes in the environment can easily transform copper sulfate into zero valent single atom copper. This is a breakthrough because the current synthetic process of single atom zerovalent copper is typically not clean, it is labor intensive and expensive,” Rodrigues stated.

“The microorganisms use a unique biological path with a range of proteins that can draw out copper (II) (Cu²⁺) and transform it into single-atom zero-valent copper (Cu⁰). The objective of the microorganisms is to produce a less poisonous environment on their own by transforming the ionic copper into single-atom copper, however at the exact same time they make something that is useful for us too.”

With a focus in electronic microscopy, Robles analyzed samples from Rodrigues’ findings in Brazilian copper mines and he identified the single atom nature of the copper. Rodrigues and Aquino’s groups even more recognized the bacterial procedure for transforming copper sulfate to essential copper – an uncommon discover.

Research results show this brand-new conversion procedure as an option to produce single atoms of metal copper is much safer, and more effective versus present approaches (i.e. chemical vapor deposition, sputtering, and femtosecond laser ablation).

“We have only worked with one bacterium, but that may not be the only one out there that performs a similar function,” Rodrigues concluded. “The next step for this particular research is harvesting the copper from these cells and using it for practical applications.”