A better / cheaper / faster / more efficient way to purify water would be great news for many places in the world. Here is one, described as a catalyst that turns water into H2O2, also known as hydrogen peroxide. Technically it’s not really purified, but if all the bacteria and viruses are killed / denatured / rendered harmless, it’s a lot more useful than it was before, even if it still smells and is kind ‘a chunkey.