3.6. BET surface areas and pore size distributions
Fig. 10. Nitrogen adsorption–desorption isotherms and the corresponding pore-size distribution curves (inset) of TCN and MCN.Figure optionsDownload full-size imageDownload as PowerPoint slide
Experimental conditions for preparation of the samples and their physical properties.SampleCompositionColorSBET/m2/gVpore/cm3/gdpore/nmTCNg-C3N4Yellow4.40.01210.7MCNg-C3N4Yellow8.00.02512.7Full-size tableTable optionsView in workspaceDownload as CSV
3.7. photocatalytic activity and mechanism
Photocatalytic BL 1249 of CO2 to methanol (CH3OH) was used to evaluate the photocatalytic activities of the as-prepared samples at ambient temperature and atmospheric pressure. Control experiments were conducted without light irradiation or catalyst, and no product was found, thus confirming that both the UV–vis light irradiation and catalyst were two essential conditions for the photocatalytic reduction of CO2. The carbon containing products were detected only when the gaseous CO2 was introduced into the reaction system, suggesting that CO2 was the only carbon source for the experiment rather than the photodegradation products of catalyst. In this work, gaseous CO2 as carbon source resulted from the reaction of analytical grade NaHCO3 and HCl aqueous solution which also offered H2O as hydrogen source. The experiment was performed in the anaerobic environment and under UV–vis light irradiation.