Designing Organic Semiconducting Polymers for Better Fuel Alternatives

Materials Studio

Scientists are looking to create bionic leaves in the search for impact free fuels and electricity. Image Source: Flickr User: HockeyholicAZ

Scientists are looking to create bionic leaves in the search for impact free fuels and electricity.
Image Source: Flickr User: HockeyholicAZ

Recent world events have made it clearer than ever: The need for alternative fuels is pressing. With efforts mounting to find viable alternatives to fossil fuels, scientists are turning towards organisms that create their own energy: plants. Scientists have developed polyaniline, an organic semiconductor polymer that reduces carbon dioxide into an alcohol fuel in a process akin to photosynthesis.1 These semiconductors have several technical advantages that researchers have only begun to explore, including flexibility and versatility. Fortunately, this is only the beginning. Moving forward, researchers would benefit from using innovative lab software that will allow them to model potential compounds before continuing. This will save them time and money while ensuring that they are able to move products to market much faster.  

Photosynthesis Beyond Plants

Chloroplasts, the organelles responsible for photosynthesis in plants, are one of the foundational molecular machines that power life. The fact that they have been utilized by a countless variety of organisms is a testament to their efficiency and versatility, and so it makes sense that humans too would attempt to harness the power of the sun in this way. Bionic leaves that produce energy from sunlight, water and air much like their organic predecessors represent an ideal sustainable alternative to fossil fuels. The most common way we have attempted to jump this evolutionary chasm is through solar cells. Solar cells are a fantastic concept, but execution is still falling shy of the full potential. The inability to efficiently store the energy created is causing a bottleneck effect with solar technologies. Researchers are now looking at the best ways to store this energy in chemical bonds, a process which can be eased with in silico modelling using innovative lab software.

Most solar-fuel generators focus too closely on ultra-violet light and expensive catalysts such as platinum. Using modern lab software, it may be possible to model potential chemical reactions to develop and deliver better solar fuel technology. In silico modelling allows researchers to test multiple hypotheses before setting about buying and assembling expensive components. Solar-fuel prototype components can be alarmingly expensive, so conducting computer simulations of the efficiency of more earth-abundant catalysts can save researchers a lot of time and money. Additionally, by examining the energy potential behind the full spectrum of visible light and earth-abundant metals (i.e. less expensive components) the potential for surpassing this bottleneck is possible. Recently, researchers used a gallium phosphide/cobaloxime hybrid to expand the amount of light absorbed and reduce catalyst costs. 2 They did see that only a small portion of the light hitting the hybrid-semiconductor surface was actually absorbed, but it was a step in the right direction. This indicated that there is great potential is widening the breadth of absorbed light. Now we only need to find the chemical combinations to do so.

Doing Away With Catalysts

Another way to avoid the cost prohibitive nature of many of the catalysts is to do away with them completely. The aforementioned semiconductor polymer does not need a catalyst. This technology is still in its infancy and will not be very efficient yet. However it does lay the foundation for more research into catalyst free solar-fuel technology. It is likely that in silico modelling with modern lab software will be the key to optimizing this technology.

In recent months, some forward-thinking catalyst free research has been geared toward looking at the properties of spinach. Popeye’s favorite snack is helping researchers create a bio-photo-electro-chemical (BPEC) cell that generates electricity and hydrogen from water and sunlight. In order to use this chemical process for electricity, scientists used an iron-based compound to the process. This compound, ferricyanide, in combination with thylakoids (isolated from spinach), mediates the electrons between the cell membrane and electric current allowing the creation of electricity, which is a thrilling concept. This electrical current can form hydrogen gas, which can be used and stored in a similar manner to hydrocarbon fuels both within and without the cell. 3 Fortunately, the harmful side-effects of burning hydrocarbon fuels are mitigated as the only product of hydrogen use is water.

Efficiency will be a key factor in the success of any of these products. With BIOVIA Materials Studio, comprehensive models can be created to allow researchers to better predict what will work saving both time and money. Materials studio can help investigators to eliminate repetitive testing by automating modelling tasks. For example, it could model and store the already existing BPEC cell and allow investigators to go through and run simulations on small modifications, such as changing the concentrations of ferricyanide or better assessing the potential of broader spectrum light absorption. The need for greener fuels is imminent, and Materials Studio can help get you there. Please contact us today to learn more about how our software options can support the efforts of your lab.

  1.  “Polyaniline films photoelectrochemically reduce CO2 to alcohols,” June 16, 2016, http://pubs.rsc.org/en/content/articlepdf/2016/cc/c6cc04050k
  2. “Energetics and efficiency analysis of a cobaloxime-modified semiconductor under simulated air mass 1.5 illumination,” February 12, 2014, http://pubs.rsc.org/en/Content/ArticleLanding/2014/CP/C4CP00495G#!divAbstract
  3.   “Hybrid bio-photo-electro-chemical cells for solar water splitting,” August 23, 2016, http://www.nature.com/articles/ncomms12552