Starting with Version 52, Firefox has this cool little feature - you can send tabs between your synced devices. Here’s how it works.
The first step is to have a Firefox account and be logged into it on all your devices. You can check this on your PC in Options > Firefox Account and on Android in Settings > Sign in (if instead of Sign in you see your email address then it means that you’re already logged in).
Go to the tab you want to send. From the overflow menu (the three dots in the top-right corner) select share and then choose the option "Send to other devices". Next, choose another synced device.
Right click on the tab you want to share and from the menu select "Send Tab to Device". Next, choose another device.
If the tab doesn't appear right away you might have to sync manually on the target device. On the PC, from the hamburger menu (the three parallel lines in the top-right corner) select the rotating arrows icon. On your Android device go to Settings, click on your account and then on Sync Now.