Is it is it possible to use Ledger with Electrum for Android ?
No it's not possible, and for other wallets it depends what kind of ledger model you have, retired S, new S plus, or worst model ever X that have bluetooth connection.
I think that open source Blockstream Green wallet supports Ledger, Trezor and Jade hardware wallets, and it's not a bad alternative for Electrum, so you could test and see how it works for you.
Maybe there are other options, but I would personally avoid anything that is closed source.
Can Ledger Nano make use of QR code to sign PSBT?
I don't think ledger can do that (but I am not sure), and even if it could it probably wouldn't be compatible with Electrum QR code format.