New oxide semiconductors for the photoelectrolysis of water: Although photovoltaic cells excel at directly converting of solar energy to electricity, they do not directly produce stored energy or fuels that account for more than 75% of current energy use. Direct photoelectrolysis of water has the advantage of converting solar energy directly to hydrogen. Unfortunately no materials are currently known to efficiently photoelectrolyze water that are, efficient, inexpensive and stable under illumination in electrolytes for many years. Nanostructured semiconducting metal oxides could potentially fulfill these requirements, making them the most promising materials for solar water photoelectrolysis, however no known oxide semiconductor has all the required properties. We have developed a simple, high-throughput combinatorial approach to prepare and screen many multi-component metal oxides for water photoelectrolysis activity. Several promising compositions have been identified and we are in the process of optimizing and understanding the physical structure, electronic structure and catalytic ability of some of these new photocatalysts. In addition, due to the millions of possible combinations to be printed and screened, we have developed a distributed research project that uses simple and inexpensive printing and screening devices to enlist many undergraduate and high school student researchers into the search for the “Holy Grail” of materials. The Solar Hydrogen Activity research Kit or SHArK project has been distributed to over sixty sites.

Photoelectrochemistry on Mars: Chemical analysis of Martian soil in the north polar region by the Phoenix Mars Lander unexpectedly detected high concentrations of perchlorate ion (0.4-0.6 weight %) that accounted for ~60% of the anionic charge and exceeded chloride concentrations by factors of 4 to 8. Initially perchlorate formation on Earth was found to be due to an atmospheric chemical reaction (ozone oxidation of chloride aerosols) and was also proposed to explain perchlorate production on Mars. We showed that highly oxidizing valence band holes, produced by ultraviolet (UV) illumination of naturally occurring semiconducting minerals, such as the anatase and rutile, are capable of oxidizing chloride ion to perchlorate in aqueous solutions.

Our results can help explain the presence and accumulation of perchlorate in the polar Martian soil during Martian spring and fall where water is present without any contribution from atmospheric chemistry. In addition, our mechanism predicts that over millennia even small amounts of semiconducting oxide minerals could eventually convert almost all the chloride to kinetically stable perchlorate, explaining the disparate perchlorate to chloride ratios found on Mars compared to those in naturally occurring perchlorate-containing soils on Earth.

Geological features and clay minerals indicate that large amounts of water were present on early Mars, however where it all went is still a mystery. We demonstrate that photoelectrochemical water splitting with a natural heterojunction cell may have been operative in early Mars history resulting in an oxidation of the surface and the hydrogen escaping the weak Mars gravity.

Dr. Bruce A. Parkinson is a member of the department of Chemistry and School of Energy Resources at the University of Wyoming.

The next e-cycling event will take place next Saturday, April 1st at the UCC Church a 300 Union Street in Northfield from 10am until noon.

As usual, please make sure to drop off all materials on site only on the collection day. Jim, the recycler, will accept a small number of CRT televisions and monitors, but they must be moveable by one person and there is a small fee for each, depending on the size.

Otherwise, all items will be accepted. If you have questions about what can or can’t be dropped off, please contact Jim directly at 651-214-3857.

Dale Jamieson is Professor of Environmental Studies and Philosophy, Affiliated Professor of Law, Affiliated Professor of Bioethics, and Chair of the Environmental Studies Department at New York University. Formerly he was Henry R. Luce Professor in Human Dimensions of Global Change at Carleton College. A leading scholar of environmental and animal ethics, he is the author of Reason in a Dark Time: Why the Struggle to Stop Climate Change Failed–and What It Means For Our Future (Oxford, 2014), and several other titles. His most recent book is Love in the Anthropocene (OR,2015), a collection of short stories and essays written with the novelist Bonnie Nadzam.

The annual Sigurd Olson Lecture Series in 2017 features Dave and Amy Freeman. Through images, video, and words, Dave and Amy will deliver a story filled with perseverance, joy, hope and their unwavering commitment to wilderness protection. These stories revolve around the work that the Freemans have done with the Campaign to Save the Boundary Waters over the last three years Come to be inspired and learning how to take further action for the Wilderness you love.

We will be cutting buckthorn, bush honeysuckle and amur cork tree in one of our forest restoration areas in the Upper Arboretum. All equipment is provided, just dress for the weather! Meet at the Arboretum trail-head kiosk in front of the Carleton Recreation Center to walk to the site. If you are running late that morning please come anyway – we will post signs to get to you to the right place. This activity goes on rain or shine but will be cancelled if hazardous weather (tornado warnings or lightening storm). No notice will be sent out, make your own judgement about weather conditions. Questions? Email nbraker@carleton.edu

Experience A Capella Improv with a great message! Social Activism in the Arts Public concert!
The Give Get Sistet is a group of 6 African American women from Minneapolis who sing a capella improvisation and every song has a great message. They sing about racism, about women’s rights, about human rights, about how human beings can love each other, about how the world could be. Their songs are in the tradition of singer songwriters like Sweet Honey in the Rock, Dylan, Pete Seeger etc. except inspiring messages for these times, using their art to teach us all the things we really need to know, but with love and deep human connection. The arts are such a great way to help us be uplifted and united at a challenging time. And help shift racism in Northfield in a beautiful way. We hope we can fill the church for their performance, 7:30 pm, Friday, March 3 at First UCC. 3rd and Union St. Northfield.
Suggested donation $10 or $25 per family, but no one turned away, all contributions accepted. Come early to get a good seat, to learn, enjoy and be uplifted and inspired, and be incredibly artistically entertained! Appropriate for all ages.