Tailoring sulfur-doped and nitrogen-defective carbon nitride nanosheets for efficient photo-controlled radical polymerizations  

作　　者：Xue Li Meng Kai Xu Yuan Huang Tao Cai 

机构地区：[1]Key Laboratory of Biomedical Polymers of Ministry of Education,College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,China [2]Wuhan University Shenzhen Research Institute,Shenzhen 518057,China

出　　处：《Science China Chemistry》2024年第7期2325-2334,共10页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(51773156);the Shenzhen Science and Technology Program(JCYJ20220530140607016)。

摘　　要：Despite the challenges that remain,the synergistic adjustment of various microstructures and photochemical parameters of graphitic carbon nitride(g-C_(3)N_(4))in photocatalytic reactions holds promises for improving catalytic efficiency and reducing energy consumption.Herein,sulfur-doped and nitrogen-defective g-C_(3)N_(4)(n-SC_(3)N_(x))nanosheets were designed and elaborately synthesized.The resultant n-SC_(3)N_(x)possessed a precisely defined 2D layer structure with extensive porosity and incremental specific surface area.Enhanced photoinduced electron transfer-reversible addition-fragmentation chain transfer(PET-RAFT)polymerization of vinyl monomers with low dispersity,excellent temporal control and high chain-end fidelity was achieved under mild blue light irradiation in a nondegassed system.Owing to their ultrathin nanostructures with nitrogen defects and sulfur dopants,n-SC_(3)N_(x)was capable of catalyzing RAFT polymerization in aqueous solutions at significantly accelerated rates,which were nearly 8 times faster compared to bulk g-C_(3)N_(4).The ease of separation and efficient reusability in subsequent polymerizations was enabled by the heterogeneous nature of n-SC_(3)N_(x).The appeal of this approach was illustrated by the fact that utilizing a reusable and metal-free photocatalyst in aqueous environments allowed for the synthesis of polymers with molecular weight up to 300 kg mol^(-1) and a dispersity of 1.32.

关 键 词：graphitic carbon nitride nitrogen defects sulfur dopants PET-RAFT polymerization RECYCLABILITY 

分 类 号：TQ316.322[化学工程—高聚物工业] O643.36[理学—物理化学] O644.1[理学—化学]