Negative Power Supply for Op Amp
Opamps don't produce voltage or current.  They let more or less current pass from the powersupply to the output.   To get a negative voltage out of an opamp, you have give it a powersupply with a negative voltage.

The output of an opamp is limited to what is available from the supply rails.  If you have rails of 0 and 12V, then that's the limits of your output.