This guy yeah?
A sketchbook drawing isn't exactly correct, yes it's drawn in what appears to be a sketchbook but that isn't a "style" of art.
This doesn't fit head to toe into any of the more well known artistic movements of the last couple of centuries. It definitely has roots and influence in art noveau. The thick, graphic quality line speak to that influence for sure. If you want to dig really deep you can go all the way to stain glass to look at influence of simple forms and clearly defined positive and negative space.
So this doesn't fit into a "style" really. It's just an ink drawing, but you can see a lot of influence in it for sure.