I'm afraid right now the only way would be to hide your NSFW projects and put them in a collection, but then they'd still be visible below the main section, or else not at all. There's no middle ground, like a separate tab.
Collections also have their own URL. If you add your NSFW projects to a collection but do not display that collection on your creator profile, I think you could then add a hyperlink to the collection in the text of the page. That way no titles or thumbnails would appear on the main profile page.
They would still appear under "creator of" in your user profile, though. I don't think it's possible to alter that list.