PhotoRec is a free tool that you can use for SD Card recovery.
Download and install PhotoRec onto your Mac.
Launch the application.
Use the command-line navigation to select the SD card storage device.
Select the partition that will be recovered.
Supply parameters to control the application’s settings.
Select the type of files to be recovered.
Choose the filesystem type.
Select a location for the storage of recovered files.
Perform the recovery.