If I were going to do it, I’d probably register some sort of PURL, and then point the QR code at that (making sure that the QR code pointed straight at it and didn’t go through some sort of shortening service that might disappear)

I’m not sure if there’s a good generic website for hosting that sort of info, though.

If you’ve ever published an academic paper, or otherwise been involved in research, you might set up an ORCID and point at that:  https://orcid.org/

(It’s more CV than business card, though.  I don’t remember if they have fields to post contact information like email and phone number)

If you’re doing it for a specific job, you might be able to point at a staff directory page, but I’ve done web development for too long, and not enough people follow the concept of ‘Cool URIs’: https://www.w3.org/Provider/Style/URI

(Which is why I suggest going through a PURL; that can always redirect to the staff directory page or whatever else.  LinkTree might work, but they could also fold like bit.ly)

-Joe