New Research on Photocatalysts for Clean Energy and Clean Waters

While most of the scientists at the Arecibo Observatory are looking up into Earth’s atmosphere and into space, Dr. Abniel Machín de Jesús is focused on issues below our feet: replacing fossil fuels with clean, renewable resources.

In a new study published in Biomimetics, Dr. Machín and his team analyzed catalysts - substances that accelerate the rates of chemical reactions - that are able to produce hydrogen via water splitting using only sunlight.

“Hydrogen has been considered as a replacement for fossil fuels,” says Dr. Machín. “Finding new, cheap, efficient and green ways to produce energy is a key goal for a sustainable future.”

The team also studied how these same catalysts could be used to degrade organic pollutants. Specifically, they looked at how antibiotics such as Ciprofloxacin can be broken down.

“Antibiotics are incompletely metabolized by humans and are excreted mostly through urine and stool,” Dr. Machín explains. “Ciprofloxacin has been detected in appreciable quantities in continental waters and reservoirs because it is highly resistant to degradation”.

“Finding new, cheap, efficient and green ways to produce energy is a key goal for a sustainable future.” - Dr. A. Machín, Executive Director of the Science & Visitor Center of the Arecibo Observatory

The concern is that bacteria can become resistant to the antibiotics when they are later ingested through the medicine-contaminated drinking water, making the drug less effective when it is needed for health purposes.
“Ultimately, we want to develop photocatalysts that are able to mimic nature to produce energy,” says Dr. Machín. Their next step is to look at photocatalysts that do not contain metals, like the silver-based photocatalysts that were used in this project, to find efficient ways to degrade antibiotics and replace fossil fuels.

With degrees in both chemistry and environmental sciences, this research was uniquely well-suited for Dr. Machín to pursue. While it is not directly related to his work as the Executive Director of the Science & Visitor Center of the Arecibo Observatory, he notes that he “always tries to talk about and inspire the visitors by describing other STEM areas, including chemistry, nanotechnology, biology and how they can be relevant to Arecibo”.