“Artificial leaf” gains ability to self-heal

One of the great things trees can do for us may one day be reproduced by man-made inventions such as the “Artificial leaf.” In the news, one artificial leaf has gained the ability to self-heal damage and it can also produce energy from dirty water.

Another innovative feature has been added to the world’s first practical “artificial leaf,” making the device even more suitable for providing people in developing countries and remote areas with electricity, scientists reported here today. It gives the leaf the ability to self-heal damage that occurs during production of energy.

Daniel G. Nocera, Ph.D., described the advance during the “Kavli Foundation Innovations in Chemistry Lecture” at the 245th National Meeting & Exposition of the American Chemical Society.

 

Nocera, leader of the research team, explained that the “leaf” mimics the ability of real leaves to produce energy from sunlight and water. The device, however, actually is a simple catalyst-coated wafer of silicon, rather than a complicated reproduction of the photosynthesis mechanism in real leaves. Dropped into a jar of water and exposed to sunlight, catalysts in the device break water down into its components, hydrogen and oxygen. Those gases bubble up and can be collected and used as fuel to produce electricity in fuel cells.

 

“Surprisingly, some of the catalysts we’ve developed for use in the artificial leaf device actually heal themselves,” Nocera said. “They are a kind of ‘living catalyst.’ This is an important innovation that eases one of the concerns about initial use of the leaf in developing countries and other remote areas.”

 

Nocera, who is the Patterson Rockwood Professor of Energy at Harvard University, explained that the artificial leaf likely would find its first uses in providing “personalized” electricity to individual homes in areas that lack traditional electric power generating stations and electric transmission lines. Less than one quart of drinking water, for instance, would be enough to provide about 100 watts of electricity 24 hours a day. Earlier versions of the leaf required pure water, because bacteria eventually formed biofilms on the leaf’s surface, shutting down production.

 

“Self-healing enables the artificial leaf to run on the impure, bacteria-contaminated water found in nature,” Nocera said. “We figured out a way to tweak the conditions so that part of the catalyst falls apart, denying bacteria the smooth surface needed to form a biofilm. Then the catalyst can heal and re-assemble.” …

 

via ‘Artificial leaf’ gains the ability to self-heal damage and produce energy from dirty water.

Deforestation, for example of the Amazon, has been called one of the leading causes of endangered species and extinction around the globe. Removing trees from an area too quickly can cause desertification, soil erosion, fewer crops, flooding, and studies show that it leads to increased greenhouse gases in the atmosphere, climate change, and problems for local people and wildlife.

Artificial leaves to help generate power and clean the environment sound great, but also, we likely still need to save the forests to save ourselves.

Update: To answer Fred’s question see this

“To overcome corrosion in water, the self-healing Co, Mn, and Ni catalysts balance their self-assembly in the presence of phosphate (Pi)orborate(Bi) anions with OER catalysis such that the equilibrium for self-assembly (i.e.,catalyst regeneration) lies energetically within that for OER catalysis (Fig. 2, Right). The self-healing catalyst is distinguished by turnover number that is infinite; that is, as long as the catalyst is operating, it is able to heal itself.”  

–

https://newsi8.com