Synthesis of tunnel structured g-C3N4 through a facile vapor deposition method using SBA-15 and KIT-6 as templates and their photocatalytic degradation of tetracycline hydrochloride and phenol

Tunnel structured g-C3N4 are synthesized through a facile vapor deposition method using SBA-15 and KIT-6 as templates, respectively. SBA-15 as a template helps to form a very thin g-C3N4 (SBA-15-CN), while KIT-6 as a template makes the g-C3N4 (KIT-6-CN) stack and aggregate. Under visible light, two samples are applied in tetracycline hydrochloride (TC) and phenol degradation, and the results are compared with that obtained by the sample prepared without template (CN). In the degradation of TC, the degradation rate constants obtained by SBA-15-CN and KIT-6-CN are 10 times and 2 times higher than CN, respectively. The improved performance of the materials is found to be primarily due to the increase of surface area caused by the unique mesoporous structure. Moreover, the unique tunnel structure and the large number of surface N vacancies are also beneficial to the transfer of photogenerated electrons, promoting the separation of photogenerated electrons and holes for SBA-15-CN. The tunnel structured g-C3N4 shows significant strong degradation and structure stability, as well as competitive photocatalytic degradation performance when compared to other reported g-C3N4 based catalysts. Furthermore, active species trapping experiments confirm that photogenerated holes and ∙O2- are the main active species for SBA-15-CN. Based on this, the photocatalytic degradation paths of TC and phenol are analyzed. [Display omitted]