## 1 Introduction
The authors claim that the exceptional CO\({}_{2}\) adsorption capacity is attributed to the presence of ultra-micropores, a significant volume of large micropores, and elevated nitrogen content. In our opinion, the significance of nitrogen content was not demonstrated here; only the values of textural parameters were shown. Nitrogen-enriched carbon, which is characterized by well-developed microporosity and exceptional CO\({}_{2}\) adsorption capacity, was synthesized via KOH activation of a nitrogen-containing polymer derived from sucrose and urea [30]. The authors acquired materials displaying diverse textural characteristics and nitrogen concentrations. The materials exhibiting the highest adsorption had the largest micropore volume and the second- and third-largest volumes of ultra-micropores, but the nitrogen content was relatively low. Nevertheless, the authors claimed that the CO\({}_{2}\) adsorption values of all the carbon materials prepared showed a strong correlation with both nitrogen content and microporsity. In our opinion, the influence of nitrogen content was not demonstrated in this case; rather, only the impact of micropore and ultra-micropore volumes was shown. The three above-mentioned works have shown that the presence of nitrogen and the ultra-micropore are critical factors for achieving high CO\({}_{2}\) absorption. The significance of micropores or ultra-micropores has been previously described, so there is no certainty whether only the volume of micropores matters and the presence of nitrogen is irrelevant. [PERSON] et al. [31] applied non-doped and N-doped activated carbon fibers with similar shapes and diameters for CO\({}_{2}\) adsorption. The textural values differed before and after the introduction of nitrogen. The highest CO\({}_{2}\) adsorption was identified for non-doped fibers. The authors acknowledged that the porous structure was the primary determinant of the fibers' CO2 adsorption capacity and that subjecting them to high-temperature ammonia treatment did not yield any positive effects. [PERSON] [32] explored the influence of O- and N-doping of three commercial activated carbons on CO2 uptake. The nitrogen content was increased through urea treatment and hydrogen peroxide oxidation, combined with urea treatment. Nitrogen and oxygen-nitrogen doping primarily affected the larger pores, diminishing the material's textural properties and, consequently, reducing CO2 adsorption. The authors demonstrated the significant influence of textural properties, which had a stronger effect on CO2 adsorption by carbon materials compared to N-doping. Many authors introduce nitrogen into activated carbons in various ways. However, such actions always lead to changes in other parameters, especially textural parameters [33]. Consequently, although these authors attempt to demonstrate the positive impact of increased nitrogen content on CO2 adsorption, the conclusions drawn from these studies are not reliable because the introduction of nitrogen involves changes in other properties. It is well-known that the textural parameters are crucial for CO2 adsorption. Simultaneous changes in nitrogen content and textural parameter values do not justify conclusions indicating that nitrogen content is the cause of changes in CO2 adsorption. According to our knowledge, there is a lack of studies presenting materials with the same textural properties but different nitrogen contents. In our study, we present commercially available activated carbon modified using barrier and spark discharge low-temperature nitrogen plasma treatment. As a result of this treatment, no properties of the activated carbon changed, except for the nitrogen concentration on the surface. This allowed us to demonstrate that the increase in surface nitrogen is the reason for the increased CO2 adsorption. The preliminary studies presented here concern a slight increase in nitrogen concentration and a slight increase in CO2 adsorption.