Disable the Nautilus Recent Files list
To permanently disable any recent files from showing up in the Nautilus Recent sidebar item, open the
~/.config/gtk-3.0/settings.ini file with a text editor:
and under "[Settings]", add the following lines:
If this file does not exist, create it. Make sure the header says "[Settings]" and not "Settings". This is how the file should look after editing it:
(there can be other items below these, of course).
To apply the changes, log out and log back in.
Copied from Webupd8 exercising (cc) BY-NC-SA WebUpd8 : Nautilus 3.6: How To Clear The Recent Files List (Or Disable It)