Author
Chunyang Nie
Bio: Chunyang Nie is an academic researcher from Guangdong University of Technology. The author has contributed to research in topics: Persulfate & Electrode potential. The author has an hindex of 8, co-authored 10 publications receiving 325 citations.
Topics: Persulfate, Electrode potential, Peroxydisulfate, Cathode, Anode
Papers
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TL;DR: In this article, the authors summarize the recent advances in graphitic carbon nitride quantum dots (g-C3N4QDs) regarding their synthesis, optical and electronic properties and photocatalytic applications for degrading organic pollutants.
Abstract: Graphitic-carbon nitride quantum dots (g-C3N4QDs), as a rising star in the carbon nitride family, show great potential in many fields involving bioimaging, fuel cells, and photo(electro)catalysis, due to their fascinating optical and electronic properties. Especially, the efficient light capture, tunable photoluminescence and extraordinary up-conversion photoluminescence properties of g-C3N4QDs may offer promising potential for full utilization of the solar spectrum, thus promoting their applications in photocatalytic reactions. Some reviews on g-C3N4 have been presented; while most of them have concentrated on g-C3N4 in 3-dimensional (3D) or 2D structures, few focused on g-C3N4QDs. Therefore, this review aims to summarize the recent advances in g-C3N4QDs regarding their synthesis, optical and electronic properties and photocatalytic applications for degrading organic pollutants. Moreover, crucial issues in g-C3N4QD future application in these flourishing research areas are discussed, with prospects towards the final realization of efficient and long-term stable g-C3N4QD-based photocatalysts.
162 citations
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TL;DR: Insight is provided into the effect of lignocellulosic biomass source on the catalytic property of biochar, which would be beneficial to screen ligne cellulose, hemicellulose and lignin biowastes to prepare high-performance biochar for water remediation.
146 citations
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TL;DR: The results suggest that the MWCNT anode/PDS is an efficient and economical metal-free electrochemical oxidative system for organic contaminants remediation and implications of operation parameters including electrode potential, energy cost, pH, etc.
128 citations
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TL;DR: In this article, recent advances in the synthesis of 2D CxNy nanocrystals and their applications in various fields are summarized, and future challenges and opportunities for developing 2D crystalline carbon nitrides for more broad applications including environmental remediation.
Abstract: Two-dimensional (2D) crystalline carbon nitrides (CxNy) with graphene-like atomic structures but semiconducting nature are new appealing materials, and increasing interest has been focused on their synthesis, properties, and applications. Apart from the well-known graphitic carbon nitride (g-C3N4), other types of 2D CxNy nanocrystals including C2N, C3N and C5N2 are also successfully fabricated in recent years and their properties and potential uses in various fields have been widely investigated. Meanwhile, g-CN, C2N2, C2N3 and C5N have been theoretically predicted, and their properties and potential applications have also been researched. Until now, 2D crystalline CxNy compounds have demonstrated promising applications in photocatalysis, electrocatalysis, gas adsorption/separation, and energy storage devices, from both experimental and theoretical aspects, stemming from their unique geometric structures, tunable electronic properties, and high specific surface area. Herein, recent advances in the synthesis of 2D CxNy nanocrystals and their applications in various fields are summarized. Moreover, future challenges and opportunities for developing 2D CxNy nanocrystals for more broad applications including environmental remediation are also discussed.
74 citations
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TL;DR: In this article, a new descriptor, local electrophilicity index (ω), which represents the oxidative capacity of adsorbed S2O82−, was included to identify the intrinsic active sites in carbocatalysts via density functional theory calculations.
Abstract: Carbon-catalyzed persulfate activation is a metal-free advanced oxidation process for abating aqueous organic micropollutants. Recently, the electron-transfer mechanism in the activation of peroxydisulfate (PDS) has attracted tremendous interest due to its unknown nonradical reaction pathways. The conventionally used atomic-scale descriptors of adsorption energy (Eads), O–O bond length (lO–O) and S–O bond length (lS–O) cannot accurately reflect the ability of the functionalities of PDS in its activation. In this work, a new descriptor, local electrophilicity index (ω), which represents the oxidative capacity of adsorbed S2O82−, was included to identify the intrinsic active sites in carbocatalysts via density functional theory calculations. To verify the reliability of the proposed criteria, the catalytic performances of a series of highly boronated and nitrogenated carbon nanotube/nanosheet composites (BCN-NT/NS) with tailored physicochemical properties were comparatively studied for activating PDS to degrade phenol. By integrating the computational and experimental results, the catalytic activity of BCN-NT/NS was determined to not only be related to the contents of heteroatom dopants (B and N), but also the positions of B and N in the co-doping configurations. This study offers reliable criteria for determining the intrinsic catalytic sites in carbocatalysts for the activation of PDS based on an electron-transfer mechanism, which assists the rational design of nanocarbons as advanced catalysts for metal-free oxidation and water remediation.
69 citations
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TL;DR: In this paper, the kinetics and mechanism of photocatalytic degradation tetracycline (TC) were investigated using three-dimensional network structure perylene diimide supramolecular organic photocatalyst (3D-PDI).
Abstract: The occurrence of antibiotics in the ambient environment has raised serious concerns. In this work, the kinetics and mechanism of photocatalytic degradation tetracycline (TC) was investigated using three-dimensional network structure perylene diimide supramolecular organic photocatalyst (3D-PDI). Under visible-light irradiation, 3D-PDI exhibited excellent degradation performance and stability for several tetracycline-based antibiotics (e.g., tetracycline; chlortetracycline; oxytetracycline.). The adsorption and degradation rate of TC by 3D-PDI were 8.21 and 12.7 times higher than that of bulk-PDI. The enhanced adsorption and degradation performance of TC by 3D-PDI were mainly due to the larger specific surface area and π-electron conjugation of 3D network supramolecular system. Superoxide radical ( O2−), hydrogen peroxide (H2O2) and hole (h+) the main reactive species (RSs) for TC degradation. Under the attack of photocatalytic RSs, TC undergoes hydroxylation, demethylation, aromatization, and ring-opening processes, and finally complete mineralization into CO2 and H2O. These results revealed that perylene diimide supramolecular photocatalyst may be efficiently applied for the remediation of tetracycline contaminated natural waters.
296 citations
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TL;DR: It is reported that defect-rich carbon nanotubes (CNTs) exhibit a superior activity in activation of peroxymonosulfate (PMS) for O MPs oxidation, and the established CNTs@PMS oxidative system achieves outstanding selectivity and realizes the target-oriented elimination of specific OMPs in complicated aquatic environment.
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.
250 citations
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TL;DR: In this paper, the evolution of bio-Fe in Enteromorpha during thermal pyrolysis and the role of the derived Fe-N-C in peroxymonosulfate (PMS) activation and organic degradation was revealed.
Abstract: Enteromorpha as a seawater pollutant was innovatively converted into a functional carbocatalyst to driven Fenton-like reactions.After direct pyrolysis of Enteromorpha at 900 °C without additional chemicals, a large number of Fe clusters and single Fe sites are anchored onto N-doped carbon matrixes (Enteromorpha-derived Fe-N-C) with a high Fe loading of 0.84 wt.%. The Enteromorpha-derived Fe-N-C exhibits a high activity in the heterogeneous activation of peroxymonosulfate (PMS) for organic pollutant degradation. Radical quenching experiments and electrochemical analysis tests verify the nonradical oxidation by high-valence iron-oxo species and an electron-transfer pathway. The single Fe atoms, which only accounted for the minority of the Fe species in Fe-N-C, acted as the dominated reactive sites for the formation of highly oxidizing FeIV=O and FeV=O sites. This work unveils the evolution of bio-Fe in Enteromorpha during thermal pyrolysis and the role of the derived Fe-N-C in PMS activation and organic degradation.
237 citations
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TL;DR: In this review, nonradical pathways and reaction mechanisms for oxidation of various organic pollutants by PDS and peroxymonosulfate are overviewed and nonradical based persulfate activation mechanisms by metal oxides and carbon materials are updated.
224 citations
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TL;DR: The radical quenching studies, electron paramagnetic resonance (EPR) measurements, and electrochemical analyses verified that the mechanism of AO7 degradation in the Fe-N-BC/PS system included both radical and non-radical pathways involving the generation of OH, SO4-, O2-, 1O2, and electron transfer.
206 citations