This was more precise.
You can use your TIP120-transistor.
Connect 12V to fan+. fan- to collector. emitter to GND. (common for Arduino and fan power)
Connect Arduino output via 330..1k resistor to base.
Measure voltage over transitor when fan is running. It should be well below 2V.
add a diode parallel to fan (kathode at 12V, anode at collector)
.....
The fan itself will draw its 150mA while running. (misread - altered current)