Iron Oxide Nanoparticles Embedded in Activated Carbons Prepared from Hydrothermally Treated Waste Biomass

• Published in: ChemSusChem Vol. 7; no. 3; pp. 875 - 882
• Main Authors: Hao, Wenming, Björkman, Eva, Yun, Yifeng, Lilliestråle, Malte, Hedin, Niklas
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.03.2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Adsorption; Biomass; carbon; Charcoal - chemistry; Flue gas; hydrothermal carbonization; iron; Magnetic Phenomena; magnetic properties; Magnetite Nanoparticles - chemistry; Nanoparticles; Porosity; Temperature; Waste Management
• ISSN: 1864-5631; 1864-564X; 1864-564X
• DOI: 10.1002/cssc.201300912

Particles of iron oxide (Fe3O4; 20–40 nm) were embedded within activated carbons during the activation of hydrothermally carbonized (HTC) biomasses in a flow of CO2. Four different HTC biomass samples (horse manure, grass cuttings, beer production waste, and biosludge) were used as precursors for the activated carbons. Nanoparticles of iron oxide formed from iron catalyst included in the HTC biomasses. After systematic optimization, the activated carbons had specific surface areas of about 800 m2 g−1. The pore size distributions of the activated carbons depended strongly on the degree of carbonization of the precursors. Activated carbons prepared from highly carbonized precursors had mainly micropores, whereas those prepared from less carbonized precursors contained mainly mesopores. Given the strong magnetism of the activated carbon–nano‐Fe3O4 composites, they could be particularly useful for water purification. Waste not; want it! Iron oxide (Fe3O4; 20–40 nm) grows and is embedded in activated carbons during the activation of hydrothermally carbonized (HTC) biomasses in a flow of CO2 (see picture). The nanoparticles formed from the iron catalyst are used for the hydrothermal treatment and are larger than the pores of the activated carbon.