TiO2/Carbon Materials Derived from Hydrothermal Carbonization of Waste Biomass: A Highly Efficient, Low-Cost Visible-Light-Driven Photocatalyst

In this paper, we present a green, low-cost carbon material derived from waste biomass (hazelnut shell (HS) and olive residue (OR)) to fabricate a binary TiO2/carbon composite for improving the photocatalytic performance of TiO2 under visible light. The synthesis, characterization, and photocatalytic applications of the TiO2/carbon composite were performed. Hydrothermal carbonization was used to obtain the carbon support materials. A series of TiO2/carbon composite materials from waste biomass based on hydrochar, fullerene, and carbon nanotubes has been prepared for comparison purposes. Photocatalytic performances of all composites were measured by comparing methylene blue (MB) removal rates. The results show that waste biomass based hydrochar/TiO2 composites possessed superior visible-light photocatalytic activity compared with high technology carbons/TiO2 composites such as fullerene and carbon nanotubes. The enhanced photodegradation capacity could be ascribed to the delocalized furanic conjugated system and functional groups of HS-TiO2 and OR-TiO2 composites.