Yes, you can make albums in Photos private. Here are the steps to make an album private on an iPhone running iOS 16:
1. Open the Photos app on your iPhone and go to the Albums tab.
2. Select the album that you want to make private.
3. Tap on the three-dots icon in the top-right corner of the screen.
4. Select "Get Info" from the dropdown menu.
5. Toggle on "Hide" under "Hide this album".
6. You will be prompted to confirm your choice by entering your passcode, Face ID, or Touch ID.
7. Once you confirm, the album will be hidden from the main Albums tab.
By making the album private, it will no longer be visible in the main Albums tab or in any other app that uses the Photos library, unless you unhide it. However, the photos in the private album will still be visible in other albums and folders in the Photos app.