Japanese scientists have synthesized layered double hydroxides with anions of sulfide and nitrite, capable of passing through the air with carbon dioxide to excrete hydrogen sulfide and nitric oxide in low concentrations. The obtained materials the authors used to create a unit to ensure a pure nitric oxide at low concentrations with the help of a respirator without the risk of overdose. A study published in Nature Communications.
Despite its toxicity in high concentrations, hydrogen sulfide and nitric oxide are physiologically active, anti-inflammatory, antioxidant, cytotoxicity and vasodilatory properties and is often used for medical purposes. Zeolites and metal-organic framework structures can communicate these gases, thus allowing to store them and release when the moisture is passed through the air. However, the use of such funds is necessary to constantly monitor the humidity, keeping it at a low level.
Layered double hydroxides represent positively charged layers of metal ions with different valencies and hydroxide ions, which are separated by a movable anions and water molecules in the interlayer space. Shinsuke Ishihara (Shinsuke Ishihara) and Nobuo Iyi (by Nobuo Iyi) from the National Institute for materials science in Japan have used the layered hydroxides of magnesium-aluminium type with anions HS− or NO2− as materials for Autonomous allocation of hydrogen sulfide and nitrogen monoxide. The authors suggested that the anions of weak acids in the interlayer space are by passing through the material to air containing carbon dioxide and water.
Then HNO2 in the reaction of disproportionation or reaction with the reducing agent forms NO. Concentration of emitted gases and the duration of this process is determined by the difference in the indicators of acidity of the acids that affect the equilibrium exchange of protons between carbon dioxide and the anions between layers of hydroxides.