Synthesis and characterization of heteroatom-enriched biochar from keratin-based and algous-based wastes

•A keratin waste was firstly used to synthesize O, N-doped biochar.•An algal biomass was firstly used to synthesize O, S-doped biochar.•The effect pyrolysis temperature and holding time were investigated.•Two biomass wastes displayed different pyrolysis characteristics.

In this work, human hair and Enteromorpha prolifera were firstly used to synthesize heteroatom-doped biochars. The effects of pyrolysis temperature and holding time on the yield and pore structure of the obtained biochars were investigated. The different pyrolysis characteristics of hair and E. prolifera were compared through thermogravimetric analyser under nitrogen atmosphere. The pore properties, surface morphology and surface chemical composition were studied by N2 adsorption, scanning electron microscopy and X-ray photoelectron spectroscopy. The biochar from hair was typical dual O, N-doped material, which possessed 21.14 at.% of O-doped and 9.61 at.% of N-doped on the surface, while the biochar from E. prolifera was typical dual O, S-doped material, which possessed 30.68 at.% of O-doped and 5.18 at.% of S-doped on the surface. The present study provides a good prospect for development of heteroatom-enriched biochar materials from renewable biomass wastes.

Graphical abstractHeteroatom-enriched biochars prepared from keratin-based (a) and algous-based wastes (b).Figure optionsDownload full-size imageDownload as PowerPoint slide