Potential Difference Driving Electron Transfer via Defective Carbon Nanotubes toward Selective Oxidation of Organic Micropollutants

Abstract

Nanocarbon-based persulfate oxidation emerges as a promising technology for the elimination of organic micropollutants (OMPs). However, the nature of the active site and its working mechanism remain elusive, impeding developments of high-performance oxidative technology for water treatment practice. Here, we report that defect-rich carbon nanotubes (CNTs) exhibit a superior activity in the activation of peroxymonosulfate (PMS) for OMP oxidation. Quantitative structure–activity relationship studies combined with theoretical calculations unveil that the double-vacancy defect on CNTs may be the intrinsic active site, which works as a conductive bridge to facilitate the potential difference-dominated electron transfer from the highest occupied molecular orbital of OMPs to the lowest unoccupied molecular orbital of PMS. Based on this unique mechanism, the established CNTs@PMS oxidative system achieves outstanding selectivity and realizes the target-oriented elimination of specific OMPs in a complicated aquatic environment. This work sheds new light on the mechanism of carbocatalysis for selective oxidation and develops an innovative technology toward remediation of practical wastewater.

Constructing the Support as a Microreactor and Regenerator for Highly Active and In Situ Regenerative Hydrogenation Catalyst

“…The high conductivity of Pd‐PDAP is attributed to the abundant π‐electrons in the sp 2 ‐hybridized C and N network, which is pivotal for the activating surface‐bound PMS and mediating electron transfer for oxidative removal of reduced sulfur species. [ 37 ]…”

“…The high conductivity of Pd-PDAP is attributed to the abundant π-electrons in the sp 2 -hybridized C and N network, which is pivotal for the activating surface-bound PMS and mediating electron transfer for oxidative removal of reduced sulfur species. [37] We also examined the possible radical production, another major PMS-activation pathway, in our system. EPR analysis shows a heptet signal of 5,5-dimethyl-2-pyrrolidone-N-oxyl (a product of 5,5-dimethyl-pyrroline N-oxide (DMPO) oxidation formed under oxidative conditions) with no characteristic signals of sulfate radical (SO 4…”

UV-Accelerated Photocatalytic Degradation of Pesticide over Magnetite and Cobalt Ferrite Decorated Graphene Oxide Composite

“…The photodegradation of organic pollutants is carried out with reactive species like hydroxyl radicles, holes, electron, etc. Therefore, radical scavenging experiment was performed to find out the key radicals involved in photodegradation of pesticide [ 31 , 32 , 33 , 34 ]. The 5 mM of each DMSO (dimethyl sulfoxide), EDTA (ethylene-diamine-tetra-acetate), and K 2 Cr 2 O 7 (potassium dichromate) were used to scavenge OH radicals, holes, and electron, respectively.…”

Photoreduction properties of novel Z-scheme structured Sr0.8La0.2(Ti1−δ4+Tiδ3+)O3/Bi2MoO6 composites for the removal of Cr(vi)

“…62,63 Generally, the inhibition of photocatalytic activity aer adding the scavenger mean the existence of corresponding active species. 35,62,64,65 Fig. 7 displays the results of active species trapping experiments.…”