Facile synthesis of Cu-based metal–organic framework/chitosan composite granules for toluene adsorption

•CuBTC/chitosan composite granules were successfully fabricated by an in situ synthesis method.•The number of Cu ions in the chitosan matrix affected the quality of CuBTC/chitosan composite granules.•The CuBTC@CS-7.5 sample exhibited high toluene adsorption capacity (120 mg g−1) and recyclability at 25 °C.•The toluene dynamic adsorption behavior was estimated using mathematical models.