As stated above, that certainly looks like a low voltage (less than 50) power plug. Unfortunately, there's absolutely no standard whatsoever as to what voltage/current/polarity/AC/DC or anything else they are. The only 'standard' is they're never used for anything higher than 50 volts.
You certainly can make up your own adapter (I've done hundreds), but you'll need to know if it's AC or DC, polarity (+ and -) if DC, voltage, current, and size of the plug. These plugs come in a myriad of different sizes, usually listed as outside diameter/inside diameter. For example, a 5.5X2.1 is 5.5MM outside diameter and 2.1MM inside diameter.
It's really difficult to tell, but that one looks like it could be 5.0X2.5 I could easily be way off though.