The 10th skill in your Tier 1 Skill Tree is the Recycling And Collection Book skill. Anytime you get a duplicate item, from Heroes to Weapons to Schematics, you should check to see if you can add it to your Collector’s Book.
As you fill out the pages of the book, Level 6 milestones will reward you with 500 V-Bucks.
Use caution to not put things in your collector’s book that you want to keep, since once you submit it for archiving, it becomes unusable. Only deposit your duplicates!