Two iCloud accounts - moving photos

I have an iCloud account that I've been using mostly for photo storage. iCloud account #1 matches a shared email address (email1). There's a great deal of photos in that account now.

email1 cloud account is being used on my iPhone, Macbook and iPad.

I want to make it so email1 cloud account is ONLY used on the iPad and email2 cloud account is used on my iPhone and Macbook.

I have a new email address and don't want to use my old email address/iCloud account any more for photo storage, but I do want to keep it open for purchases only (I am giving my iPad to my grandmother and want to keep paying for her apps etc with the email1 iCloud account). I am currently paying for extra cloud storage with email1. My phone and Macbook Pro also use the email1 account for sign in. I want to take it off these devices but keep it on the iPad.

I created a new iCloud account with the new email address (email2). How can I move email1 photos in the cloud to email2 cloud and switch my iPhone and Macbook to email2 cloud account?