Application specific do not disturb

One workaround that I see a lot is to ask your workplace for a dedicated work phone - if they expect you to be reachable outside of office hours, then they've likely got some legal obligation to provide this.

When you're not working, turn it off.

On the other hand, if you can't just let go of work when you get home, that is a whole different problem and possible solutions I can think of are to keep yourself busier by getting a new pet, child or lover. This is especially true if you already have at least one of these.

Screen Time will be available in iOS 12 and it has the ability to mark some applications as off-limits (snoozing) between certain hours. This may suit your needs.