Direct Conversion of Sunlight to Hydrogen – Cheaply

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

We’ve witnessed several attempts to produce an “artificial leaf,” a device emulating the photosynthesis of plants, but providing hydrogen and oxygen that could power fuel cells in electric vehicles instead of plant sugars to make trees and flowers grow.  One of the biggest problems so far has been the rare and costly materials necessary to generate hydrogen. Ècole Polytechnique Fédéral de Lausanne (EPFL) scientists have come up with a low-cost alternative, using abundant materials called perovskites and budget electrodes to produce hydrogen from water with a 12.3 percent conversion efficiency – a record for fairly common materials. Perovskites are a calcium titanium oxide mineral that come in a variety of colors and can be bog-common or extremely rare, approaching rare earth mineral status.  The CaTiO3 used by Michael Grätzel is of the common variety, but that doesn’t seem to detract from its performance as a hydrogen-production agent. That, and the inexpensive materials used in the device’s electrodes cause Jingshan Luo, a post-graduate …

Rust and Sunshine Do Mix

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Chemists at Boston College in Chestnut Hill, Massachusetts, “Have achieved a series of breakthroughs in their efforts to develop an economical means of harnessing artificial photosynthesis by narrowing the voltage gap between the two crucial processes of oxidation and reduction, according to their paper, “Hematite-Based Water Splitting with Low Turn-on Voltage,” published this week in the journal Angewandte Chemie.” With your editor wishing he’d paid more attention in high-school chemistry, a quick search came up with simple definitions of oxidation and reduction. Oxidation is gain of oxygen. Reduction is loss of oxygen. When reduction and oxidation take place simultaneously, this is known as a redox reaction. These types of reactions take place in leaves producing plant energy from sunlight, and researchers are closing in on duplicating the reactions at a level which will make artificial photosynthesis an inexpensive, practical way to collect and store energy. So far, they’ve managed to produce 80 percent of the necessary voltage levels from their unique photoanodes and photocathodes.  …