Catalysis

Adsorption

Composite number

Engineering

Biology

Materials science

Raw material

Lignocellulosic biomass

Bioenergy

Potassium hydroxide

Miscanthus

Carbon fibers

Chemical engineering

Activated carbon

BET theory

Waste management

Miscanthus sinensis

Organic chemistry

Biofuel

Biomass (ecology)

Agronomy

Composite material

Chemistry

Pulp and paper industry

Lignin

Specific surface area

Scientific Reports

Herein, value-added materials such as activated carbon and carbon nanotubes were synthesized from low-value Miscanthus × giganteus lignocellulosic biomass. A significant drawback of using Miscanthus in an energy application is the melting during the combustion due to its high alkali silicate content. An application of an alternative approach was proposed herein for synthesis of activated carbon from Miscanthus × giganteus , where the produced activated carbon possessed a high surface area and pore volume of 0.92 cm 3 .g −1 after two activation steps using phosphoric acid and potassium hydroxide. The S BET of the raw biomass, after first activation and second activation methods showed 17, 1142 and 1368 m 2 .g −1 , respectively. Transforming this otherwise waste material into a useful product where its material properties can be utilized is an example of promoting the circular economy by valorising waste lignocellulosic biomass to widely sought-after high surface area activated carbon and subsequently, unconventional multi-walled carbon nanotubes. This was achieved when the activated carbon produced was mixed with nitrogen-based material and iron precursor, where it produced hydrophilic multi-wall carbon nanotubes with a contact angle of θ = 9.88°, compared to the raw biomass. synthesised materials were tested in heavy metal removal tests using a lead solution, where the maximum lead absorption was observed for sample AC-K, with a 90% removal capacity after the first hour of testing. The synthesis of these up-cycled materials can have potential opportunities in the areas of wastewater treatment or other activated carbon/carbon nanotube end uses with a rapid cycle time.

The production and application of carbon nanomaterials from high alkali silicate herbaceous biomass