Simple latching broom handle clamp. Prints without need for support and uses nail/rivets or something about 1.7mm in diameter as the hinge pins. I've had better luck with using something metal like this method as oppsoed to a print in place pin.

This particular one was made with holding a 21mm diameter handle in mind, but could fit similar diameter. Could also scale it up, but screw holes in pin hinges will need adjusted as well. I've added a third counter-sunk hole in the center for mounting something that might not need two screws to avoid needing to put more than one hole in the wall.

Tip: For heavier/slippery handles try covering the inside of the flaps with hot glue or rubber bands.