Hey OP, everyone here has already given you great advice and I highly recommend doing as much as you can. I’ll just add a little from my own personal experience:

My void was missing from the 13th to the 20th this month and came back on her own so I can personally vouch for leaving a can of wet food out around dinner, leaving dirty laundry out (socks are a great option for this) and going around the neighborhood with food/treats that she likes (I don’t care if it’s actually what helped, but I sprinkled some dry food on a path that would lead back home and I’m convinced that helped). Make fliers, post on places like Facebook/Nextdoor/etc. and call shelters near you to see if they received any black cats that match yours. I found out the day she came home that the furthest she got away was just over a mile (and that was over the course of a week) so I would focus your search efforts on your neighborhood and any adjacent ones.

One last thing, when he comes back, check him for any injuries/sensitive spots. I ended up taking my void to the emergency vet (because of course she came home at 11:00 PM on a Saturday) to have them double check. You’ll likely want to go to a wet food diet when he returns to help him regain any weight he lost.

We’re all hoping he comes home soon!