Researcher vs Educator: A Fork in the Academic Road

Assistant professors aspiring for tenure at major research institutions generally understand that poor teaching or instruction skills rarely count against them. Individual professors may take it upon themselves to improve these skills, but it isn’t expected or demanded.

Research (i.e. funding and publishing) is prioritized to the point that student learning barely registers in tenure decisions. As an aspiring academic, this continues to prompt me to ask: Would I have greater impact on the chemistry community if I focused on research or instruction? (The question implies a forced dichotomy that could be addressed. For example, universities could hire ‘research faculty’ and ‘instruction faculty’, but I digress…) Exploring this further, I wonder: Will I have greater impact if I dedicate myself to full-time research, ignoring the education aspect, and - through a combination of hard work and luck - maybe solve a big problem or discover something ground breaking? Or would I have greater impact if I committed myself to instructing and preparing bright and motivated students to solve the world’s problems? Collectively, could these students contribute more than I could alone?

While I sometimes revisit these questions, I’ve made a decision. My ultimate goal is to be a research professor and my overarching priority will be research. Yet, while my (hoped-for) job and tenure offers will be based on my research prowess, I do not plan to completely ignore my role as an educator. I ultimately think that my ability to conduct ground breaking research – and perhaps solve a big problem - will be significantly better if I have highly skilled and educated students at my side.

Read more »

Subscribe to the comments for this post

An Earth-Abundant Photoelectrochemical Cell: One Step Closer to a Hydrogen Economy?

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 generating PEC. In fact two different architectures for the PEC were investigated and both can be seen below.

The article describes a triple junction amorphous silicon solar cell (3jn a-Si) as the light absorbing and charge separating component which creates the electricity necessary to run the electrolysis of H₂O. The 3jn a-Si is composed of alternating layers of amorphous silicon and amorphous silicon-germanium alloy on a stainless steel back plate. Unlike the devices described in the previous post, the 3jn a-Si can produce > 2 V of driving force and thus it does not require a power supply to run catalysis.

Read more »

Subscribe to the comments for this post

Your Dream Job Awaits!

The Interdisciplinary Centre for Advanced Materials Simulation (ICAMS) at the Ruhr University in Bochum, Germany  recently posted an opening for a post-doctoral researcher to study "Atomistic simulations of structural rearrangements at solid-solid interfaces." Shortly after the announcement was posted the email below was sent to the PSI-K community - a network created by researchers all over Europe to facilitate cooperation and collaboration in the field of electronic structure calculations. Members usually use the PSI-K listserv to distribute and receive information about workshops, conferences and job announcements.

To: PSI-K

Subject: [ PSI-K ] postdoc position at Department Atomistic Simulation ICAMS Ruhr-Univ. Bochum

Category: Job

From: juttar ogal

Date: 09-Sep-2011 17:57

Message:

I am desperately searching for eager victims - postdocs or PhD students - mine or other supervisors' - to make my workhorses and to plunder ideas from. I am a dirty Hun who seethes from jealousy out of every pore. I cannot do research myself because I'm narrow-minded, rigid-brained, and petty. Therefore, I have to recruit desperate scientists from anywhere in the world and then manage (harangue) them into submission. The smarter you are relative to me, the more I will hate you. If you complain, you will be threatened by my gang of goons - faculty and administration are all allied with me in order to achieve our clan's goal of world domination which has eluded us for the last century or so. The reward for taking up this Faustian bargain with me is good renumeration - but if you start to complain or expose the secret of my incompetence to others, especially outsiders, then you will be let go as we cannot tolerate traitors within our ranks. ALL credit for your work will go to me and my gang of inbred dullards, not to you. We are ruthless gangsters who recruit legitimate scientists from all over the world to do our work because we cannot do any of it ourselves - due to severe brain rigidity brought about by centuries of inbreeding the traits of blind obedience, robotization, and general dullness. The techniques which we employ to keep these victims productive is nagging, threats and psychological abuse, facilitated by the university's administration. Eventually, the victims give up all credit for their research to us. I have no conscience since I am a psychopath. I am entitled to success because supremacy is my birthright.

Please send your CV and three references to jutta.rogal@rub.de

The above email (and another I did not see) was soon followed by a message from the PSI-K Chairman and Vice Chairman:

Dear Psi-k members,

We want to shortly comment on the two e-mails sent last Friday by the fake user "juttar ogal". This was an unfortunate misuse of the Psi-k mailing list. Fortunately up to now it was also the only incident noted. Obviously, these e-mails were not sent by our long term Psi-k member and highly respected scientist Jutta Rogal.

We are very sorry that this has happened and will take appropriate measures for the future.

With best regards,

Peter Dederichs        Walter Temmerman

Psi-k Chairman         Psi-k Vice Chairman

Prof. Peter H. Dederichs
PGI, Forschungszentrum Jülich
D-52425 Jülich, Germany

e-mail: p.h.dederichs@fz-juelich.de

Who sent the emails? A disgruntled employee? An aspiring comedian trying to reach a larger audience? The email is clearly over the top, yet many employees can relate to some of the messages embedded in the hyperbole. Post docs and graduate students acknowledge that we are working to make our advisers famous or more famous. We know that we may not receive full credit for fame-inducing ideas.

Additionally, there are few options for graduate students and postdocs disgruntled with their bosses. Human relation's resources  are limited or underutilized in science departments. A conflict between an adviser and a graduate student results in the student joining another research group or leaving school. Postdocs move on to a new position, assuming they receive a reasonable letter of recommendation.

So is the best way to deal with these issues an anonymous, inflammatory email? Probably not. But we should acknowledge that this response alludes to greater issues within the system.

Subscribe to the comments for this post

Molecules that Changed History

Chemistry courses, particularly introductory courses, often cover at least some history of the field. I remember learning straight facts like “Dr. x discovered y in…” or theory development like “Greek atomism was replaced by the plum pudding model, which in turn was replaced by the Bohr model.” Yet, minimal time is spent discussing how the discovery or creation of new chemicals impacted the world outside of the lab and shaped human history.

This is understandable. There was plenty to cover and to be honest history was never my favorite subject anyway.

Despite my lack of interest in history, I have gained some piecewise stories and factoids over the years about chemistry’s impact on human history. It was after reading Napoleon’s Buttons: 17 Molecules That Changed History, by Penny Le Couteur and Jay Burreson, that I feel I can say I have an overview about the true history-shaping nature of molecules/chemistry.

Rather than being a chronological account, as with most history books, the molecules are the main characters in Napoleon’s Buttons. Each chapter is divided into different classes of molecules and their impact tracked from as early as 5000 BC to present day. The pursuit of specific atomic arrangements caused colonialism, vicious battles, and the end to these aggressions – particularly when just the right synthetic pathway was discovered. Our chemical history is not entirely bleak - chemicals have also been used to save innumerable lives.

One thought provoking trend introduced in the book is the recall of one-time ‘miracle’ molecules. DDT, CFCs, phenol and others were employed far and wide before their dangerous and accumulative effects were fully understood. Without committing to full blown conspiracy theories, this information makes me apprehensive of some recent chemical advances. I might think twice before I eat too much artificial sweetener, especially the chlorinated compounds like sucralose.

One critique I have of the book is that the title is a bit of a misnomer. Rather than focusing on 17 molecules they cover 17 classes of molecules, including dyes, nitro compounds, chlorocarbons, sugars, and more. Also, one of the chapters is dedicated to salts like NaCl and NaHCO₃ which are technically not molecules because they lack covalent bonds.

For those seeking a book written specifically for chemists, Napoleon’s Buttons is probably not for you. It is definitely written for a more general audience. A seasoned veteran of chemistry can easily skip the few pages in each chapter that introduce structures (e.g. each corner is a carbon, what a polymer is and so on) and still gain insight into the historical context of the molecules.

I highly recommend this book, especially for teachers. It provides compelling anecdotes that will not only tie lessons together, but also demonstrate the importance of the work that we as chemists are doing.

Subscribe to the comments for this post

Build Your Own Dye-Sensitized Solar Cell

In 1991 Brian O’Regan and Michael Gratzel published a paper titled “A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO₂ films.” This paper is the foundation for an entire branch of solar energy conversion research known as dye-sensitized solar cells (DSSC).

The basic operation of a DSSC is summarized in the schematic below. In roughly a stepwise manner:

1. Light (hν) hits a light-absorbing molecule ( chromophore, C), causing it to enter an energetically excited state (C*).
2. The excited chromophore injects an electron (e^-) into the anode.
3. The iodine (I^-) in solution donates an e^- to the previously oxidized C and combines with I₂ to become I₃^- .
4. The high energy e^- from step 2 enters the external circuit where it can be used to perform work on a load (e.g., charge a battery, run a fan).
5. The low energy e^- then continues to the cathode where it catalytically reduces I₃^- to I^- and completes the circuit.

The 1991 Gratzel paper was groundbreaking because it introduced the use of a high surface area TiO₂ semiconductor electrode as the anode material. With a higher surface area, more chromophore can be loaded on the surface to increase light absorption and thus can generate more photocurrent. Using this basic architecture - with variations to its components - has allowed us to realizef efficiencies greater than 10% in the lab. Companies like Dysol and others are currently commercializing this technology.

As well as being groundbreaking the DSSC is relatively simple with four basic components: an anode acceptor material, a chromophore, a reversibly redox active electrolyte and a cathode material that can catalytically reduce the electrolyte. Given the availability of these components, Greg P. Smestad and Michael Gratzel later published a procedure in the Journal of Chemical Education that allows just about anyone to create their own DSSC. The Institute of Chemical Education (ICE), based out of the University of Wisconsin, has taken the educational utility of this paper one step further and  created a $45 Nanocrystalline Solar Cell Kit. The components of this kit can be seen in the figure below. It consists of 1) 10 x SnO₂ conductive glass slides, 2) 15 mL of I^-/I₂ ethylene glycol solution, 3) 25 g TiO2 powder, 4) a soft graphite pencil, 5) 10 x binder clips and 6) a variable resistor.

All that you need in addition to the kit is an oven/hot plate that can sinter the film at 450°C; a dye that can be easily obtained from raspberries, blue berries, black berries or other fruits; and a mortar/pestle to grind up the TiO₂ while adding acetic acid. The assembled solar cell is shown in the top left of the image. From the kit you can make up to five solar cells at a time and, because many of the components are reusable, the process can be repeated several times. The ICE manual that comes with the kit provides clear instructions for assembling, characterizing and cleaning the devices. It also includes background information, visual aids, graphing paper, teaching suggestions and other useful tips/hints for trouble-shooting the devices.

While DSSCs are currently being studied by graduate students and researchers all over the world, the concepts and components of these devices are so simple that they can be used for teaching activities in middle schools and undergraduate chemistry labs. In fact, last week I had the pleasure of demonstrating this kit/exercise for local high school and middle school science teachers through a program sponsored by the University of North Carolina at Chapel Hill’s Institute for the Environment.

I have been involved with solar cell technology as a researcher for several years, and I can say without a hesitation that I was blown away by how user-friendly the kits are – especially given the high level of science involved. For example, you can construct the circuit in the image to the right (top) using two $10 multimeters from Radio Shack, the variable resistor that comes with the kit and your fully assembled cell. While shining light on the cell and changing the variable resistor, the relationship between the current (I) and voltage (V) can be documented (The graph of voltage versus current is a common sight to anyone that has studied solar cells.)  An incredible amount of information can be obtained from these I/V curves, like open circuit voltage (V_oc), short circuit current (I_sc), power maximum (P_max), fill factor (FF), shunt resistance (R_SH) and series resistance (R_S). Also, if you know the power of incident light (P_inc = 800-1000 W/m², for daytime sunlight) you can calculate the device efficiency (h) by dividing P_max by P_inc.

The DSSC kits are exciting because of the various opportunities they provide to teach high level scientific concepts and troubleshooting through simple hands on activities. Middle school students can compare different dyes and their effect on the devices' efficiencies/current/voltages. Undergraduate inorganic chemistry students can synthesize and compare various dyes. These exercises can also bring together concepts in biology, chemistry, and physics classes. For example, students can prepare chlorophyll dye through enzymatic reactions in a biology lab,  fabricate and load the dye on the TiO₂ films in chemistry class, and then do the I/V characterization or measure the parallel versus series currents of several devices in physics class.

Subscribe to the comments for this post

Artificial Leaf or Solar Powered Electrosynthesis?

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 is this: how close to natural photosynthesis does a solar fuel cell have to be for us to reasonably consider it an artificial leaf? Is it enough that a device absorbs sunlight and makes chemical bonds? If that is the case then a bond forming reaction driven by a solar-powered hotplate could be considered an artificial leaf. Is it defined by the chemical bonds that are formed or is a well-defined molecular geometry for the photon absorption and electron transfer events sufficient? An official line between artificial photosynthesis and solar powered chemistry has not yet been drawn. I do not set out to define that line here but I do want to call attention to the differences in recent “artificial leaf” devices and describe how they fall short of their aspiring names while simultaneously indicating that a true artificial leaf may be imminent.

One “artificial leaf” receiving buzz at the moment is being publicized by MIT professor Daniel Nocera. The catalytic portion of this artificial leaf has a cobalt phosphate thin-film anode and a yet to be published nickel cathode.  When these electrodes are submerged in a pH 7 phosphate-buffered aqueous solution and a potential of 1.3 V vs NHE is applied, water is catalytically oxidized at the anode to give O₂. The remaining protons are reduced at the cathode to give hydrogen.  The hydrogen and oxygen can then be used for hydrogen fuel cells.

The applied potential to run the catalysts can come from any source: a water-wheel, a wind turbine, a person riding a bicycle equipped with a generator or any other device that generates electricity. In the case of Nocera’s artificial leaf the potential is created by hooking the electrocatalytic device described above to a silicon solar cell. By describing the device in this way I try to emphasize why I dislike its designation as an “artificial leaf.” It is only an artificial leaf in the most superficial sense in that it converts sunlight into molecular bonds. However, in a more logistical sense it is simply a solar cell (a more than 125 year old technology) attached by wires to a electrocatalytic cell (a more than 200 year old technology).

I am in no way trying to belittle the research of Professor Nocera but I am questioning the use of the descriptor “artificial leaf” rather than focusing on the device’s interesting and important materials. The water oxidation catalyst is not only composed of relatively inexpensive cobalt ions but it can also be electrodeposited on an electrode from a solution of Co²⁺ and phosphate. The importance of electrodeposition is twofold: 1) it makes production of the catalyst relatively easy and 2) it offers a mechanism for self-repair of the catalytic material.

When the line is drawn a true artificial leaf should, at the very least, integrate the two devices into one operational component that generates charges (ideally on a molecular level) and delivers oxidative/reductive equivalents to the catalysts. A simplified, one component system may also reduce the production and operational costs of such a device. Professor Nocera, his collaborator Professor Buonassisi and their colleagues have taken one step closer to a true artificial leaf in their recent publication in the Proceedings of the National Academy of Sciences. In this paper they describe a device where they combined the two component system into one by depositing the electrocatalytic cobalt material directly onto a silicon solar cell. The device can be seen below (not pictured are the Ag/AgCl reference and the platinum counter electrodes):

In this device’s architecture a standard p-n junction silicon solar cell  is coated on one side with metal contact and semi-transparent photoresist. The other side of the solar cell is coated with an indium tin oxide (ITO) layer and then the catalytic cobalt phosphate thin film. Under illumination the silicon absorbs photons to generate an exciton (a bound electron hole pair) which is separated at the p-n interface to give a free hole and an electron. The electron travels to the metal contact and then to the external circuit while the holes travel through the ITO layer to the cobalt film. The cobalt film then catalytically oxidizes H₂O to O₂.

When a silicon wafer is put under illumination in an aqueous solution an insulating layer of SiO₂ will form that kills the photocurrent. The key to using a silicon solar cell in this architecture is to passivate the surface of silicon with photoresist and ITO so the silicon will not get oxidized. Using this strategy they created a device that can generate oxygen from water consistently for at least 6 days.

Although the device is predominantly driven by photon energy, a single silicon solar cell unfortunately does not have the driving force to oxidize water. An external applied potential was still necessary to generate O₂. Despite this shortcoming, this is a great proof-of-concept device that, as the paper states, is “analogous to the wireless current in natural photosynthesis.” (It can be argued that the ITO in this case is acting as the wire but that is just more semantics). 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.

Although I do not think we have yet created a true “artificial leaf” and that we should be vigilant to avoid sensationalism, results like those described above as well as progress in other solar fuel strategies signal that man-made photosynthesis is on the horizon and a future powered by solar fuels is within our grasp.

Subscribe to the comments for this post

Energy Frontier Research Centers

We cannot meet the expanding energy needs of our growing human population using oil-dependent, 19^th century technology. We need to expand renewable energy technologies, develop methods for storing renewable energy, and clean up problems generated from our oil dependency like atmospheric CO_2.

The U.S. Department of Energy’s (DOE) Office of Basic Energy Sciences is supporting this goal by funding scientific innovation on the atomic and molecular scale - the foundation of renewable energy technology. One such effort is the Energy Frontier Research Centers (EFRC) program which was established to “integrate the talents and expertise of leading scientists in a setting designed to accelerate research toward meeting our critical energy challenges.”

Each of the 46 EFRCs represent a collaborative unit that can contain universities, national laboratories, nonprofit organizations, and for-profit firms (mapped out below). Beginning in 2009 each center receives $2-5 million per year for a 5-year period to focus on one of the following: advanced nuclear systems, catalysis, clean and efficient combustion, electric energy storage, geological sequestration of CO₂, materials in extreme environments, hydrogen science, biofuels, solar energy utilization, solid state lighting, and superconductivity.

On May 25-27, 2011, the DOE will host the first Science for Our Nation's Energy Future: Energy Frontier Research Centers Summit & Forum to gather researchers from all the EFRCs and discuss recent progresses and the challenges ahead. The summit will include notable speakers like Steven Chu (U.S. Secretary of Energy) as well as presentations and posters by gradate students, research scientists and professors (The Official Agenda). The event is free and open to the public but you must register ahead of time.

In a build up to the summit, the DOE invited the EFRCs to produce a 2-3 minute video that “educates, inspires, and entertains an intelligent but not expert audience about the extraordinary science, innovation and people” involved with the program. Between now and May 24^th a contest is underway to decide which of the 26 submitted videos is the public’s favorite. The winning video will be shown at the EFRC Summit and may be featured on the DOE YouTube channel, Science for Our Nation's Energy Future website, and the DOE websites. Please vote for your favorite here. Here are a few of my favorite videos, in case you’re interested:

Subscribe to the comments for this post

Successful Failures

Many, if not the majority, of research projects end up as ‘failures’. I use the term failure because the project simply fails to reach the pre-defined goals. Useful knowledge is usually still gained, such as why you could not reach the goal or why the goal is unreachable. Unfortunately, knowledge about what not to do is less publishable and therefore less likely to be shared.

It is a tragedy that this knowledge from failure is not shared with others and added to the compendium of human understanding. Without a method for capturing and disseminating this information, countless researchers in countless labs end up having to reinvent failures many times over. The same mistakes are allowed to happen because there are few if any forums for researchers to learn why their proposl might not work.

A few years ago I stumbled upon the Journal of Negative Results in BioMedicine. In this journal biologists and biochemists share the results of their 'failed' experiments. After posting a link to this journal on the chemistry subreddit Mitch and I got into a discussion about starting a Journal of Failed Chemistry, an open access, peer reviewed journal to share failed chemistry projects and the too often underappreciated knowledge they produce. We decided to wait until we were more established in our careers before tackling the project because we wanted more credibility to support the journal.

I am excited to share with as many people as I can that someone beat us to it. The All Results Journals: Chem is currently accepting submissions in an effort to “compile and publish articles with undesirable results and their interpretations written up in common scientific format after a peer review process.”

All articles are written in standard journal format and each submission will be sent out to one or more reviewers as chosen by the editors. Every published article is available online free of charge in open access format to support a greater global exchange of knowledge.

While this journal is still in its fledgling stages I hope that everyone recognizes its importance and provides support. Its success rests on the shoulders of those willing to both submit and review the articles. Please take a look at the online submission guidelines to see if you have something fitting for the journal (I would wager that anyone who’s completed a Doctoral thesis has at least one chapter that fits the criteria). Also if you are willing and interested in being a reviewer check out the requirements and fill out an application.

For those of you who are interested, check out the other All Results Journals for Biology, Physics and Nanotechnology.

Related side note: I pass on the advice I was once given as a graduate student – while doing an original research proposal, like the one required during most qualifying exam processes, be able to answer the question “If you fail to reach the goals of your proposal, what will you have learned?” The most valuable proposals to the scientific community at large are not just the ones that present a unique way to go after a problem but also the ones that will help humanity better understand the inner workings of the universe.

Subscribe to the comments for this post

Promoting Science One High School at a Time

I grew up in Foley, Minnesota, a small town (population: 1600 people) in the middle of nowhere. My early world view was shaped by a very homogeneous local population, television, and movies. For example, my isolated perspective made me think that Hollywood was a vision of wealth and fame. Then I moved to Los Angeles for graduate school and these visions were shattered in one fell swoop during my first trip to a shockingly crowded Hollywood strip that offered souvenir stands, sex-toy/lingerie shops, and shattered dreams.

Without meeting a scientist, a similar contrast between reality and imagination can also emerge. Impressions of science and scientists can instead be based on movies like Frankenstein, The Fly or others. For many, this impression can also be affected by anti-evolutionists and climate-change deniers who demonize scientists.

To help add reality into this equation I decided to do what I could, one talk at a time, starting with my former high school. At the beginning of March I was a visiting speaker for my former teacher, Dave Voeltz, in three chemistry classes and one physics class. This was my first attempt at showing the reality of being a scientist and, more specifically, the importance of science and chemistry.

Sam Mueller, my friend since high school, agreed to video tape my talk, cut together some of the more important points, and create a video. I am sharing this video with you with the hope of spreading the importance of science to an even greater audience. Here is the outcome of his 48 hour, video-editing binge (Thanks Sam). I apologize preemptively for my compulsive swaying. With much energy comes much movement.

If you are interested in more of Sam Mueller’s work check out the preview for his latest film Raising Sparrows, which is currently making the documentary film circuit.

Subscribe to the comments for this post