How to create learning environment for devs?

I’m a senior software engineer for a Fortune 500 company and my developing team has around 12 people. I’d like to create a learning atmosphere and get people talking and learning. I created a slack channel where I post coding challenges and links to useful information but I don’t think I’m getting the interactions I would like. I know people get busy but what are some good ways to get people excited to learn new things and create an environment where people are learning? Thanks for the advice.