86794-33-4Relevant academic research and scientific papers
Nanopore enriched hollow carbon nitride nanospheres with extremely high visible-light photocatalytic activity in the degradation of aqueous contaminants of emerging concern
Yang, Yuxin,Hu, An,Wang, Xinyue,Meng, Jiaqi,Guo, Yihang,Huo, Mingxin,Zhu, Suiyi
, p. 355 - 365 (2019)
Construction of highly efficient hollow nanosphere photocatalytic systems has been strongly attracting the attention of researchers. In the present work, nanopore enriched hollow carbon nitride nanospheres (HCNNSs) with a smaller particle size (200 nm) and a thinner shell thickness (40 nm) are successfully fabricated by a silica-nanocasting strategy. Such unique structures possess many advantages such as large BET surface area (122 m2 g-1), high light-harvesting ability, fast charge separation and transfer efficiency, plentiful exposed active sites and enhanced oxidation ability of photogenerated holes (h+VB). Therefore, HCNNSs in smaller sizes (HCNNS-200) exhibit extremely excellent visible-light photocatalytic efficiency towards the degradation of contaminants of emerging concern, e.g. levofloxacin (LEVO), in comparison with bulk g-C3N4 and HCNNSs in larger sizes (HCNNS-500). And it takes less than 10 min to finish the degradation of LEVO. The experimental results including those from indirect chemical probing, electron spin resonance, ion chromatography and high performance liquid chromatography-mass spectrometry confirm that h+VB and O2- are the active species that are responsible for the mineralization of LEVO to NO3-, F-, H2O and CO2 under visible-light irradiation. Additionally, the degradation pathway of LEVO in the HCNNS-200 photocatalytic system is also proposed. It is expected that HCNNS-200 can be used as a promising photocatalyst for environmental remediation.
Facile synthesis of carbon quantum dots loaded with mesoporous g-C3N4 for synergistic absorption and visible light photodegradation of fluoroquinolone antibiotics
Wang, Yingfei,Wang, Fengliang,Feng, Yiping,Xie, Zhijie,Zhang, Qianxin,Jin, Xiaoyu,Liu, Haijin,Liu, Yang,Lv, Wenying,Liu, Guoguang
supporting information, p. 1284 - 1293 (2018/02/07)
The development of facile and efficient synthetic approaches of carbon quantum dots loaded with mesoporous g-C3N4 (mpg-C3N4/CQDs) is of critical urgency. Here, a facile strategy was developed to synthesize the mpg-C3N4/CQDs by using calcinations of the mixture of CQDs, cyanamide, and silica colloid. The obtained composite still retained a considerable total surface area, which could offer a larger population of adsorption sites; therefore enhance the capacity for the adsorption of fluoroquinolones antibiotics (FQs). Under visible light irradiation, mpg-C3N4/CQDs demonstrated a higher photocatalytic activity for FQs degradation than did bulk g-C3N4 or mpg-C3N4. This enhancement might have been ascribed to the high surface area of the mpg-C3N4, unique up-converted photoluminescence (PL) properties, and the efficient charge separation of the CQDs. The eradication of FQs followed the Langmuir-Hinshelwood (L-H) kinetic degradation model and absorption pseudo-second-order kinetic model, indicating that surface reactions and chemical sorption played significant roles during the photocatalysis process. The results of electron spin resonance (ESR) technology and reactive species (RSs) scavenging experiments revealed that the superoxide anion radical (O2-) and photo-hole (h+) were the primarily active species that initiated the degradation of FQs. Based on the identification of intermediates and the prediction of reactive sites, the degradation pathways of ofloxacin (OFX) were proposed. A residual antibiotic activity experiment revealed that mpg-C3N4/CQDs provided very desirable performance for the reduction of antibiotic activity.
