Synthesis of two-dimensional mesoporous carbon nitride under different carbonization temperatures and investigation of its catalytic properties in Knoevenagel condensations

Abstract

A two-dimensional mesoporous carbon nitride (MCN-1) material with tunable surface area, pore volume and nitrogen content has been synthesized by using carbon tetrachloride and ethylenediamine as precursors and SBA-15 as a template. The effect of the carbonization temperature on the textural properties, N content and the types of nitrogen species of the MCN-1 samples was also investigated by several characterization techniques. The results reveal that the higher temperature favors the formation of porous structure during the thermal condensation process. In addition, the nitrogen content and the surface N/C ratio in the samples monotonically decrease with the increase of carbonization temperature.The catalytic activity of MCN-1-T is not only related to its surface nitrogen content but also dependent on the structural diversities of the surface nitrogen species. The MCN-1 sample synthesized at 400 C shows the higher catalytic activity and stability for Knoevenagel condensations.

Effect of Heat Treatment on the Nitrogen Content and Its Role on the Carbon Dioxide Adsorption Capacity of Highly Ordered Mesoporous Carbon Nitride

“…This peak is assigned to the (002) plane and is characteristic of interplanar stacking peaks of an aromatic system. [29,30] It should be noted that the intensity of highero rder peaks increasesw ith increasing carbonization temperature, revealing ac hange in the crystallinity of the samples at differenttemperatures.T he intensity of the highero rder peak is much higher for E-MCN-1-1000t han that of other samples, which suggests high crystallinity in the sample. [29,30] It should be noted that the intensity of highero rder peaks increasesw ith increasing carbonization temperature, revealing ac hange in the crystallinity of the samples at differenttemperatures.T he intensity of the highero rder peak is much higher for E-MCN-1-1000t han that of other samples, which suggests high crystallinity in the sample.…”

“…[28] The d spacingc alculated from the (002) plane is around 0.34-0.35 nm for the samples;t his is similar to the value obtained forn onporous carbon nitrides and indicates that the wall structure of these samples is composed of carbon and nitrogen arrangedi naturbostratic form. [29,30] It should be noted that the intensity of highero rder peaks increasesw ith increasing carbonization temperature, revealing ac hange in the crystallinity of the samples at differenttemperatures.T he intensity of the highero rder peak is much higher for E-MCN-1-1000t han that of other samples, which suggests high crystallinity in the sample.…”

“…TheR amans pectrao fa ll samples show two distinct and intense bands at 1371a nd 1575 cm À1 ,w hich are attributed to the D( disordered)a nd G( graphitic) bands of the sp 2 -hybridizedc arbon. [30] Normally,t he relative intensity of Da nd G bands in the Ramans pectrum gives information about the quantity of structurald efects in the CN wall structure of MCN. It is interesting to note that the I D /I G ratio of E-MCN-1-600 is 0.85, whereas it increases to 0.94 as the carbonization temperature is increased to 900 8C.…”

Copper nanoparticles incorporated on a mesoporous carbon nitride, an excellent catalyst in the Huisgen 1,3‐dipolar cycloaddition and N‐arylation of N‐heterocycles

“…The SEM images of MCN and Cu NPs‐MCN are shown in Figure a‐b. The MCN exhibits a tubular structure with uniform particles, which the diameters are about 300 nm, being highly similar to those of the parent SBA‐15 template that shows the successful replication process of MCN from SBA‐15 . The morphology of MCN do not change after the incorporation Cu NPs onto the MCN framework (Figure b).…”

A Metal-Free Carbon-Based Catalyst: An Overview and Directions for Future Research

“…The metal-free catalyst also was invoked for many well-known organic reactions, including Knoevenagel condensation [124], cycloaddition [125], dehydrochlorination [126], transesterification [127], catalytic oxidation of cyclic olefins [128], and so forth. Besides, the industrial effluents contain several organic and inorganic pollutants which are acutely toxic and difficult for biodegradation [129].…”