easily manage you wallpaper dynamically with i3wallpaper
You cane have one wallpaper per workspace
pip install git+https://github.com/samsja/i3wallpaper
then create a config files in ~/.config/i3wallapaper/config.toml
ex:
[wallpapers]
1 = "path_to_your_wallpaper1"
2 = "path_to_your_wallpaper2"
where each of the lines correspond the image you want for the given workspace