{"id":1995468,"date":"2023-03-06T13:39:19","date_gmt":"2023-03-06T18:39:19","guid":{"rendered":"https:\/\/wordpress-1016567-4521551.cloudwaysapps.com\/plato-data\/mof-catalyst-purifies-herbicide-tainted-water-and-produces-hydrogen\/"},"modified":"2023-03-06T13:39:19","modified_gmt":"2023-03-06T18:39:19","slug":"mof-catalyst-purifies-herbicide-tainted-water-and-produces-hydrogen","status":"publish","type":"station","link":"https:\/\/platodata.io\/plato-data\/mof-catalyst-purifies-herbicide-tainted-water-and-produces-hydrogen\/","title":{"rendered":"MOF catalyst purifies herbicide-tainted water and produces hydrogen"},"content":{"rendered":"\nMar 06, 2023<\/td>\n<\/tr>\n\n (Nanowerk News<\/em>) Researchers in the Oregon State University College of Science have developed a dual-purpose catalyst that purifies herbicide-tainted water while also producing hydrogen.\n<\/td>\n<\/tr>\n\n\nThe project, which included researchers from the OSU College of Engineering and HP Inc. is important because water pollution is a major global challenge, and hydrogen is a clean, renewable fuel.\n<\/td>\n<\/tr>\n\n\nFindings of the study, which explored photoactive catalysts, were published today in the journal ACS Catalysis<\/em> (“Two Birds, One Stone: Coupling Hydrogen Production with Herbicide Degradation over Metal\u2013Organic Framework-Derived Titanium Dioxide”<\/a>).\n<\/td>\n<\/tr>\n\n\"Graphic<\/td>\n<\/tr>\n\nGraphic depicting how new photocatalyst works. (Image: OSU)\n<\/td>\n<\/tr>\n\n\n\u201cWe can combine oxidation and reduction into a single process to achieve an efficient photocatalytic system,\u201d OSU\u2019s Kyriakos Stylianou said. \u201cOxidation happens via a photodegradation reaction, and reduction through a hydrogen evolution reaction.\u201d\n<\/td>\n<\/tr>\n\n\nA catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.\n<\/td>\n<\/tr>\n\n\nPhotocatalysts are materials that absorb light to reach a higher energy level and can use that energy to break down organic contaminants through oxidation. Among photocatalysts\u2019 many applications are self-cleaning coatings for stain- and odor-resistant walls, floors, ceilings and furniture.\n<\/td>\n<\/tr>\n\n\nStylianou, assistant professor of chemistry, led the study, which involved titanium dioxide photocatalysts derived from a metal-organic framework<\/a>, or MOF.\n<\/td>\n<\/tr>\n\n\nMade up of positively charged metal ions surrounded by organic \u201clinker\u201d molecules, MOFs are crystalline, porous materials with tunable structural properties and nanosized pores. They can be designed with a variety of components that determine the MOF\u2019s properties.\n<\/td>\n<\/tr>\n\n\nUpon MOFs\u2019 calcination \u2013 high heating without melting \u2013 semiconducting materials like titanium dioxide can be generated. Titanium dioxide is the most commonly used photocatalyst, and it\u2019s found in the minerals anatase, rutile and brookite.\n<\/td>\n<\/tr>\n\n\nStylianou and collaborators including L\u00edney \u00c1rnad\u00f3ttir of the OSU College of Engineering and William Stickle of HP discovered that anatase doped with nitrogen and sulfur was the best \u201ctwo birds, one stone\u201d photocatalyst for simultaneously producing hydrogen and degrading the heavily used herbicide glyphosate.\n<\/td>\n<\/tr>\n\n\nGlyphosate, also known as N-phosphonomethyl glycine or PMG, has been widely sprayed on agricultural fields over the last 50 years since first appearing on the market under the trade name Roundup.\n<\/td>\n<\/tr>\n\n\n\u201cOnly a small percentage of the total amount of PMG applied is taken up by crops, and the rest reaches the environment,\u201d Stylianou said. \u201cThat causes concerns regarding the leaching of PMG into soil and groundwater, as well it should \u2013 contaminated water can be detrimental to the health of every living thing on the planet. And herbicides leaching into water channels are a primary cause of water pollution.\u201d\n<\/td>\n<\/tr>\n\n\nAmong an array of compounds in which hydrogen is found, water is the most common, and producing hydrogen by splitting water via photocatalysis is cleaner and more sustainable than the conventional method of deriving hydrogen \u2013 from natural gas via a carbon-dioxide-producing process known as methane-steam reforming.\n<\/td>\n<\/tr>\n\n\nHydrogen serves many scientific and industrial purposes in addition to its energy-related roles. It\u2019s used in fuel cells for cars, in the manufacture of many chemicals including ammonia, in the refining of metals and in the production of plastics.\n<\/td>\n<\/tr>\n\n\n\u201cWater is a rich hydrogen source, and photocatalysis is a way of tapping into the Earth\u2019s abundant solar energy for hydrogen production and environmental remediation,\u201d Stylianou said. \u201cWe are showing that through photocatalysis, it is possible to produce a renewable fuel while removing organic pollutants, or converting them into useful products.\u201d\n<\/td>\n<\/tr>\n\n\nThe collaboration that included graduate student Emmanuel Musa, postdoctoral researcher Sumandeep Kaur and students Trenton Gallagher and Thao Mi Anthony also tested its photocatalyst against water tainted by two other often-used herbicides, glufosinate ammonium and 2,4-dichlorophenoxyacetic acid. It worked on water containing them as well \u2013 even water with those two compounds plus PMG.\n<\/td>\n<\/tr>\n