In June I wrote a blog post titled “Artificial Leaf or Solar Powered Electrosynthesis?” about a photoelectrochemical cell (PEC) described in the Proceedings of the National Academy of Sciences (PNAS). The goal of this research was to create a PEC that can use sunlight to split water (H2O) into oxygen (O2) and hydrogen (H2). The stored energy in hydrogen can then be used to generate electricity via a hydrogen fuel cell. In that post I described the device and how it operates. It essentially has a water oxidation catalyst on top of a p-n junction silicon solar cell. It was a step toward a solar driven device, but unfortunately the solar cell alone did not provide the force (>1.23 V) necessary to drive water oxidation and proton reduction.  The cell had to be supplemented with an external power supply. The device marked a great step forward but not quite a standalone earth-abundant PEC. I concluded the post with the sentence “With further optimization, possibly involving a tandem solar cell architecture, I have no doubt we will see a fully functioning device within the next few years.” While I was technically right in my timeline (< a few years) my estimate was clearly too pessimistic. A follow up paper to the PNAS publication was published last week in Science. The article “Wireless Solar Water Splitting Using Silicon-based Semiconductors and Earth-Abundant Catalysts”  by Daniel Nocera and the team at Sun Catalytix introduces a fully functional hydrogen and oxygen...

The tendency for sensationalism in science reporting is a problem. Phrases in a peer-reviewed article that say “this discovery could lead to applications such as x, y, and z” undergo a sensationalist spin when it’s reported that scientists have “discovered a cure for cancer,”  “found THE cause of schizophrenia,” or “increased solar cell efficiency by 50%!” Sometimes the reporter facilitates the translation. Other times it is the researcher. The unfortunate result of this type of reporting is desensitization and, even worse, an increased skepticism of scientific claims. When a really important discovery comes along it is appropriately met with “AGAIN? Really?” and “well, then where is my flying car?”  For the sake of maintaining the public’s trust and support, scientists should do what they can to avoid sensationalism. To avoid sensationalism in the area of solar fuels research we should be more thoughtful and critical about the use of the term “artificial leaf.” A leaf in nature uses the energy in sunlight to split water and convert carbon dioxide into energy-rich sugars, adenosine triphosphate, and other organic molecules in a process we know as photosynthesis. This complex process contains a number of stepwise events involving geometrically organized proteins and small molecules located in the chloroplast. I am not going to discuss the individual steps but I encourage everyone to read up on this incredible machinery. The question I now pose...