Controlling multiple 24V solenoids with Arduino
No, it won't:


The diode D1 is backwards.
The opto-coupler is wired completely wrong.


You don't actually need the opto-coupler as long as the threshold voltage of the MOSFET is low enough for the Arduino to switch.  However if you do want (or need) to use it you should wire it like this:







simulate this circuit &ndash; Schematic created using CircuitLab

R1 is a pull-down that keeps the MOSFET off when not being turned on (just like with a button). The value doesn't matter much.  R2 is a resistor just like you use for any LED with an Arduino.  D1 must be connected reverse biased or it will just short out your solenoid. The opto-coupler must be connected with the transistor the right way around or it will not work (or melt, or create a black hole...)

To ditch the opto-coupler you can just treat it like any other load on the Arduino (as long as the MOSFET's threshold voltage VGS is below 4V):







simulate this circuit