Nocturnal witchcraft is a common expression in the witchcraft world these days as a way of describing the side of witchcraft that is darker. That's not to say it's "black magick" but that it looks more to the darker perspective and embraces the energy of the night and the Moon.
It's not that specific and I don't have any certain spells just yet that would fall under the nocturnal banner. Not yet anyway. Depending on your point of view, the pages on binding spells or banishing spells would qualify, and I do have a new section on black magic spells you can explore now.
Places like PaganSpace.net and WiccanTogether.com both use the term for their darkness-embracing groups. And of course, there is the popular book by Konstantinos called "Nocturnal Witchcraft: Magick After Dark".
It's actually a very good book, and written in an easy-to-read style that comes across as just having a conversation with someone. The topic is well explained, and focuses on the fact that "dark" is not the same thing as "bad" or "evil".
Spells and rituals are presented to let you embrace an interest in night magick, and to see the situations when it is the best approach to doing witchcraft.
Once you've covered the subject with this book, you can try some of his other works as well:
Leave the Nocturnal Witchcraft page and go back to the Witchcraft Spells page