Water is a strange molecule and even after centuries of research, irrespective of the number of strange things discovered about it, there are still unexpected results waiting to be unearthed. In a new case study, researchers in the United States have discovered that under the proper circumstances, water can spontaneously produce hydrogen peroxide which is a strange aspect of fundamental chemistry that was hiding in plain sight, unnoticed till now. The work appears in PNAS journal.
Richard Zare, a chemist at Stanford University says that since water is one of the most commonly found elements which has been studied for several years, it is normally expected that there is nothing else to learn about it.
Scientists observed the phenomena with pure water, and just any form of water will not do. According to the team, hydrogen peroxide can be produced when water is atomized into microdroplets which measure between 1 micrometer to 20 micrometers in diameter. One micrometer is one-thousandth of a millimeter, hence it is understood that the droplets are very small in size. At this infinitesimal scale, hydrogen peroxide is formed spontaneously even when there is nothing else present apart from water.
For this process, there is no necessity of chemical reagent, catalyst, electrical potential or radiation. The only requirement is pure water in microdroplet form. This phenomenon was discovered accidentally in previous research while investigating how gold nanoparticles and nanowires can be produced using water droplets. Those experiments revealed that water microdroplets besides accelerating the synthesis of the gold nanostructures also results in their spontaneous formation.
Zare’s team conducted several tests such as spraying pure water microdroplets on a test strip which turned blue if hydrogen peroxide was present. The yield of hydrogen peroxide production was inversely proportional to the size of microdroplet. Researchers think that the spontaneous oxidation of water takes place due to the presence of strong intrinsic electric field between water and air microdroplets, where hydroxyl radicals combine to form hydrogen peroxide in the presence of an electric field.
Further research is needed to test this hypothesis, although there is no ambiguity regarding the generation of hydrogen peroxide itself. This could lead to more eco-friendly ways of producing hydrogen peroxide. Research like this opens doors to innovative opportunities such as green and affordable production of hydrogen peroxide, environment-friendly synthesis of chemicals, safe cleaning and food processing. This is a surprising discovery even to someone such as Zare who himself holds 11 honorary doctorates and considers it to be one of the most significant discoveries.