Established in 2020 Saturday, February 24, 2024


Electroactive bacterium generates well-defined nanosized metal catalysts with remarkable water-splitting performance
Using bacteria to produce metal nanoclusters could be a greener and more efficient way to produce precious catalysts used in industry. Image courtesy: KAUST; Anastasia Serin.



THUWAL.- A biological method that produces metal nanoclusters using the electroactive bacterium Geobacter sulfurreducens could provide a cheap and sustainable solution to high-performance catalyst synthesis for various applications such as water splitting.

Metal nanoclusters contain fewer than one hundred atoms and are much smaller than nanoparticles. They have unique electronic properties but also feature numerous active sites available for catalysis on their surface. There are several synthetic methods for making metal nanoclusters, but most require multiple steps involving toxic substances and harsh temperature and pressure conditions.

Biological methods are expected to deliver ecofriendly alternatives to conventional chemical synthesis. Yet, to date, they have only led to large nanoparticles in a wide range of sizes. "We found a way to control the size of the nanoclusters," says Rodrigo Jimenez-Sandoval, a Ph.D. candidate in Pascal Saikaly's group at KAUST.

Having previously shown that the surface of electroactive bacterial cells could serve as a support for single metal atoms, Saikaly's team explored the creation of biohybrid materials. These consisted of palladium nanoclusters anchored to the bacterial surface of G. sulfurreducens cells. This bacterium, readily found in soil, can transfer electrons to metals present outside the cell and can also conduct electricity when grown on an electrode of a microbial electrochemical system. In this project, it acted as a reducing agent and a conductive scaffold for the nanoclusters.

Drawing from nanoparticle chemical synthesis, the researchers decided to control the metal precursor concentration in their setup, and their attempt paid off, Jimenez-Sandoval says. "To come up with this idea, we had to think of G. sulfurreducens as a chemical entity instead of a biological entity."

They discovered that adding the metal precursor step by step was the key to fine-tuning nanocluster size and distribution and, ultimately, catalytic performance.

As a proof of concept, the researchers evaluated the catalytic performance of the as-synthesized nanoclusters anchored to the bacterial surface for the overall water-splitting reaction, which involves electrochemically breaking down water into gaseous hydrogen and oxygen. The nanoclusters outperformed benchmark platinum- and iridium-based catalysts used for the hydrogen and oxygen evolution reactions in alkaline solutions.

"These results have very important implications in real life applications because a catalyst synthesized with a biological method is not only cheaper and simpler but also greener," Jimenez-Sandoval says.

The study is published in the journal ACS Sustainable Chemistry & Engineering.

The team is now working to produce a biohybrid catalyst that does not rely on noble metals but a more abundant and cheaper material to enhance the sustainability of their strategy.







Today's News

March 19, 2023

Antibody fragment-nanoparticle therapeutic eradicates cancer

Satellite powered by 48 AA batteries and a $20 microprocessor shows a low-cost way to reduce space junk

Immune-cell booster for cancer patients

DNA treatment could delay paralysis that strikes nearly all patients with ALS

Scientists discover giant insect genome

Team successfully generates mouse models for two subtypes of multiple myeloma

Coupling light and matter to ensure optimum brightness for displays

"Denoising" a noisy ocean

Losing a key type of pancreatic cell may contribute to diabetes

How fishermen benefit from the reversing evolution of cod

Climate change creates 'win-win' between bald eagles and farmers

Genetic causes of three previously unexplained rare diseases identified

Humans bite back by deactivating mosquito sperm

Scientists develop energy-saving, tunable meta-devices for high-precision, secure 6G communications

Electroactive bacterium generates well-defined nanosized metal catalysts with remarkable water-splitting performance

Researchers discover a new approach to harvesting aerial humidity with organic crystals

3D-printed revolving devices can sense how they are moving

'Terminator zones' on distant planets could harbor life, astronomers say



 


Editor & Publisher: Jose Villarreal
Art Director: Juan José Sepúlveda Ramírez



Tell a Friend
Dear User, please complete the form below in order to recommend the ResearchNews newsletter to someone you know.
Please complete all fields marked *.
Sending Mail
Sending Successful