5 links have been added on this idea.
  1. I found this automatic, no-contact door opener designed for handicapped toilets, but it could also work perfectly in public toilets.
    https://www.olideautodoor.com/touchless-washroom-handicap-door-opener-commercial-automatic-door-with-non-contact-handicapped-switch/

  2. Well, sensor-operated hand dryers are pretty common in public washrooms, but they are anything but hygienic.

  3. I found this website selling automatic, wall-mounted, hands-free toilet flush plates.
    https://www.uk.roca.com/rocalife/discover-our-toilet-flush-sensor-plates