Tuning CNT Properties for Metal-Free Environmental Catalytic Applications

Abstract

Abstract:The application of carbon nanotubes (CNTs) as metal-free catalysts is a novel approach for heterogeneous liquid phase catalytic systems. Textural and chemical modifications by liquid/gas phase or mechanical treatments, as well as solid state reactions, were successfully applied to obtain carbon nanotubes with different surface functionalities. Oxygen, nitrogen, and sulfur are the most common heteroatoms introduced on the carbon surface. This short-review highlights different routes used to develop metal-free carbon nanotube catalysts with enhanced properties for Advanced Oxidation Processes.

Mechanically activated carbonized rayon fibers as an electrochemical supercapacitor in aqueous solutions

“…Ball milling process has been applied to modify the properties of various carbonaceous materials including carbon nanotubes (CNTs) [21][22][23][24][25][26], graphite [27,28] and activated carbon cloth [29]. For instance, ball milling, transformed CNT's into nanoparticles [21].…”

Influence of carbon anode properties on performance and microbiome of Microbial Electrolysis Cells operated on urine

“…An increase of the CO and CO 2 peaks corresponds to an increase in the amount of functional groups containing oxygen. The TPD peaks were assigned to the different oxygen functional groups by comparison with the data exhibited [23,24]. According to Chen and coworkers, oxygen-containing groups on the carbon surface improve the surface hydrophilicity and the contact between the electrode surface and electrolyte [25].…”

Carbon nanotubes as catalysts for wet peroxide oxidation: The effect of surface chemistry

“…One way to increase their reactivity is to introduce surface groups through thermal, chemical, or physical treatments. This allows the nature and concentration of surface functional groups to be fine-tuned to specific applications [15]. For example, oxidation treatments with nitric acid, hydrogen peroxide, or ozone introduce oxygen-containing surface groups such as carboxylic acids and anhydrides, lactones, phenols, carbonyls, and quinones, with different acidic/basic properties [16,17].…”