This is a wonderful idea, incredibly simple and definitely something worth creating.
That said, we can all see the obvious problems: it collects very little water and it's a bit difficult to manage. The trouble with making the collection part of the ring any wider is that a lot of water will condense on the bottom of it and thus be wasted --same with making the walls taller, water would gather on the outside wall and just be cycled back into the unclean water.

What this thing needs is a spout. And a second bottle. Or, reasonably, just another container to hold the purified water, but there's no shortage of plastic bottles, so.

With a small spout, maybe 2" to 3" long and a 1/4" - 1/2" wide, at a minor angle from the ring, the water can still be collected in the ring, but now funnel to another container. This reduces the risk of spilling the clean water, and also increases the amount of dirty water that the bottle can hold as the ring will have to be placed a bit higher up in the container (midway or so). Of course, the collection time for the clean water will increase just from the larger amount that can be purified at once, but it saves a lot of mucking about with having to empty the purification ring every time it fills to capacity.

A notch would have to be cut into the bottle to allow for the spout, but I don't believe this would greatly impede the condensation process. If a second two-liter is used for clean water collection, a notch would also have to be cut into that one, but really any secondary container would work.

In case I haven't explained this properly, please enjoy this incredibly crude and not to scale at all mock-up drawing.

LH Water Purification Ring.jpg

I'm not sure of the specifics for printing this, as I currently and sadly do not have my own 3D printer. In fact I saw Les Hall's video posted on Twitter with a link to this forum and made an account just to post my idea. I'm not sure if others have thought of the same, or perhaps even better ideas, but I think it's a worthwhile thing and I wanted to at least contribute in some small way.

--Cheers then,
Mai