Hybrid composite of modified commercial activated carbon and Zn-Ni hydrotalcite for fermentative hydrogen production

•The composites of modified commercial activated carbon (mCAC600) and hydrotalcite (HT) showed a 30 % increase in H2 production.•Core metal elements of hydrotalcite are Zn and Ni, forming Zn-Ni-HT.•Enhancement was due to the hybrid functions of Zn-Ni-HT/mCAC600.•Their roles in fermentative hydrogen production were reported and discussed.