How do you become a senior, without having one?

So here's the gist of it. I work as a software dev in a research institute. The team is super young and pretty much just has people right from university. With my ~1 year of work experience I'm the "senior".

How do I improve and gain skills without having anyone to discuss this with? There's no one doing code reviews, etc.
Any tips on how to grow into this position?