Application Of Heteroatom Doped Ordered Mesoporous Carbon For Detection And Removal Of Typical Pollutants In Water

Ordered mesoporous carbon?OMC?materials,with high specific surface area,tunable pore size,highly ordered mesoporous structure,and good catalytic capability and electrical conductivity,are emerging carbon materials in recent decades.The doping of heteroatoms can introduce rich defect structures and abundant functional groups on the surface of OMC,which is beneficial to the improvement of its catalytic capability and electrical conductivity.These advantages make OMC materials have great application potential in contaminant detection and removal.In this paper,the application of sulfur-doped and nitrogen-sulfur co-doped OMC in organic pollutant removal and heavy metal detection were investigatedThe first section,an electrochemical aptasensor based on nitrogen-sulfur co-doped ordered mesoporous carbon?SN-OMC?and T-Hg²⁺-T mismatch structure for detecting Hg²⁺in water was raised.The aptasensor used ferrocene as signal molecules to achieve the conversion of current.In the absence of Hg²⁺,the thiol modified T-rich probe 1 spontaneously formed a hairpin structure by base pairing.In the presence of Hg²⁺,the hairpin structure of probe 1 was opened due to the preferentially formation of T-Hg²⁺-T mismatch structure.SN-OMC with high specific surface area and ample active sites acted as a signal amplification element in electrochemical sensing.The sensitive determination of Hg²⁺can be actualized by analyzing the relationship between the change of oxidation current caused by ferrocene signal molecules and the Hg²⁺concentrations.The aptasensor had a fine linear correlation in the range of0.001-1000 nM with detection limit of 0.45 pM.The aptasensor also displayed a good response in real sample detection and provided a promising possibility for in-situ detection.The second section,sulfur-doped ordered mesoporous carbon?S-OMC?as a metal-free catalyst for catalytic removal of p-nitrophenol?PNP?in water.Persulfate?PS?was activated to degrade PNP by synthesizing three different sulfur doping amounts of S-OMC.Of which,the activation effect of the medium sulfur doping amount?2.0 wt.%?is the most obvious,and the removal rate of PNP can reach 82.02%.It can be seen from that the appropriate amount of heteroatom introduction is essential for the activation effect.Normal temperature environment and contaminant solution without pH adjustment can achieve the optimal experimental effect,retrenching energy and chemical input for practical applications.Moreover,the structural features and surface characters of S-OMC were studied and found that the defect structure and surface functional groups had noticeable influence on the reusability of S-OMC.More importantly,both radical activation and non-radical activation were detected.The radical pathway oxidized pollutant by generating?OH,SO₄??,and O₂??.Of which,?OH was dominated.While the non-radical pathway attacked contaminant by continuous electron transport between PNP,S-OMC and PS.This research provided a new perspective on the application of heteroatom doped ordered mesoporous carbon materials and presented an easy and effectual way for the removal of organic contaminants.