Good for CTR, but remember that they don’t always render well on every browser or device so keep that in mind. If you add it to the end of a serp title or description it has less chance of disrupting your title or description if it renders badly or just shows a square box.
Emoji doesn’t make an impact on your ranking, it’s nor a ranking factor. You can do better use of emojis in social sharing or in any other content sharing platforms. It may helps in increasing your CTR, bcz with Emojis your content title can catch attention of users.
But using of emojis also depends on what kind of product/service you are offering to users.