Use email or chat to direct attention,
use a team wiki to store information.
Email and chat usually carry a high-level of urgency, but make it pretty hard to refer to key pieces of information later. This makes it that much harder to develop useful knowledge over time.
One key factor is making it easy to capture information into packages that are individually addressable.
This makes it easy to curate tham – to make connections, collect related packages and combine them into new, higher-level ideas.
So use semi-ephemeral channels like email and chat to direct attention and tools with a better information architecture to store information.