A large-nanosphere/small-nanosphere (cellulose/silver) antibacterial composite with prominent catalytic properties for the degradation of p-nitrophenol

•A cellulose/Ag composite with a novel structure, large/small nanosphere, was prepared.•A unique nanosphere surface support efficiently supported the Ag nanoparticles.•The composite exhibited good antibacterial activity against the E. coli and S. aureus.•The composite possessed excellent catalytic properties for the degradation of 4-NP.•The composite was efficiently synthesized by Ag+ reduction on spherical nanocellulose.