Degradation Of P-chlorophenol Research Articles

Robust advantage of MXene/g-C3N4 loaded on Fe2WO6/BiIO4 nano-platform for chemo-peroxidase colorimetric detection of uranyl ions, antifungal properties, photocatalytic degradation of p-chlorophenol, and eco-toxicity studies

In this study, we have designed a nanocomposites based on MXene/g-C3N4 (MX/CN) loaded on Fe2WO6/BiIO4 (FWO/BIO) for different applications. The nanocomposites were identified by using the structural and morphological studies including XRD, FESEM, EDS, DLS, TGA, BET, UV–vis, XPS techniques. The average sizes of BIO, FWO/BIO, and MX/CN/FWO/BIO were 44, 46, and 58 nm, respectively. The synthesized MX/CN/FWO/BIO nanocomposites was utilized for the peroxidase colorimetric identification of uranyl ions (UO22+) with the excellent selectivity and sensitivity properties (LOD: 3.21 nM). The antifungal efficiency of the as-fabricated nanomaterials was investigated and the inhibition zone at high concentration 2.5 mg/mL of MX/CN/FWO/BIO nanocomposites were 19.74, 17.91, 24.25, and 21.32 mm against Aspergillus spp., Penicillum spp., Candida spp. and Fusarium spp., respectively. The MX/CN/FWO/BIO nanocomposites was utilized in photocatalysis process for decomposition of p-chlorophenol under visible light lamp. The findings showed that the MX/CN/FWO/BIO nanocomposites can be degrade p-chlorophenol (100.0 %) under visible light irradiation (80 min). The photocatalytic response was decreased about 2 % after 5th cycle times, and showed the best stability of the MX/CN/FWO/BIO nanocomposites. The quenching test shows the mechanism of p-chlorophenol degradation was conducted by •O2−, and •OH species. Additionally, the ecological structure activity relationships ECOSAR software was utilized to evaluate the toxicity of the p-chlorophenol and the intermediates produced. This work can lead for manufacturing innovation in near future.

Strategically tailored double S-scheme heterojunction in h-MoO3 doped Bi7O9I3 decorated with Cr–CdS quantum dots for efficient photocatalytic degradation of phenolics

Phenolic compounds are widely used in various industrial processes, but they can be harmful to the environment if released without proper treatment. In this study, we developed a ternary nanocomposite (NCs) consisting of molybdenum trioxide, bismuth oxoiodide, and chromium-doped cadmium sulphide quantum dots h-MoO3/Bi9O7I3/Cr–CdS QDs (MBC) nanocomposite (NCs) to enhance the photocatalytic degradation of p-chlorophenol (p-CP). The nanomaterial morphology, distribution of depositing material, and heterojunction formation were investigated using SEM, TEM, SAED, and elemental mapping. Further, the structural characterization was done by XRD, XPS, and Raman spectroscopy which confirmed its purity, chemical states, bonding nature, and the presence of oxygen vacancies (OVs) and sulphur defects. The 30-MBC NCs exhibited the highest surface area of 354.5 m2/g and pore volume of 0.76 cm3/g, with the H3 hysteresis loop indicating their mesoporous nature. The Kubelka-Munk plot determined the band gap of the NCs to be 2.22 eV and ensured successful visible-light sensitization. PL and ESR studies revealed that 30-MBC NCs had the lowest charge carrier recombination and highest ROS production. The photocatalytic degradation of p-CP by 30-MBC NCs achieved 94% in 300 min. The highest efficiency was observed at 75 mg/L NCs, 150 mg/L p-CP, and pH 6. Additionally, NCs retained activity in the presence of different ions and degraded 82% p-CP even after six consecutive cycles. •O2− was the dominant ROS involved in the degradation process, while OVs and sulphur defects played a crucial role in ameliorating charge transfer in the 30-MBC NCs. GC-MS/MS analysis identified the possible degradation pathways of p-CP, and ECOSAR showed that less toxic by/end products were produced. Overall, this study highlights the promising potential of 30-MBC NCs for extensive wastewater treatment.

Insights into the efficient water treatment over N-doped carbon nanosheets with layered minerals as template: The role of interfacial electron tunneling and transfer

Peroxymonosulfate (PMS) oxidation reactions have been extensively studied recently. Due to the high material cost and low catalytic capability, PMS oxidation technology cannot be effectively applied in an industrial water treatment process. In this work, we developed a modification strategy based on enhancing the neglected electron tunneling effect to optimize the intrinsic electron transport process of the catalyst. The 2D nitrogen-doped carbon-based nanosheets with small interlayer spacing were prepared by self-polymerization of dopamine hydrochloride inserted into the natural layered bentonite template. Systematic characterizations confirmed that the smaller layer spacing in the 2D nitride-doped carbon-based nanosheets reduces the depletion layer width. The weak electronic shielding effect derived by the small layer spacing on the material subsurface enhanced the bulk electron tunneling effect. More bulk electrons could be migrated to the catalyst surface to activate PMS molecules. The PMS activation system showed ultrafast oxidation capability to degrade organic pollutants and strong ability to resist interference from environmental matrixes due to the optimized electron transfer process. Furthermore, the developed membrane reactor exhibited strong catalytic stability during the continuous degradation of P-Chlorophenol (CP).

Expression of Concern: “Synergistic visible light assisted photocatalytic degradation of p-chlorophenol and rifampicin from aqueous solution using a novel g-C3N4 quantum dots incorporated α-MoO3 nanohybrid – Mechanism, Pathway and toxicity studies” (Chemosphere, Volume 339, October 2023, 139529)

Expression of Concern: “Synergistic visible light assisted photocatalytic degradation of p-chlorophenol and rifampicin from aqueous solution using a novel g-C3N4 quantum dots incorporated α-MoO3 nanohybrid – Mechanism, Pathway and toxicity studies” (Chemosphere, Volume 339, October 2023, 139529)

Insight on the degradation of P-chlorophenol based on the Co-g-C3N4/diatomite composite photo-Fenton process

The non-metallic photocatalyst g-C3N4 is characterized by non-toxicity and straightforward preparation. Still, the drawbacks of low specific surface area and fast carrier complexation rate limit its practical application in photocatalysis. In this work, Co-doped g-C3N4 was prepared on the surface of diatomite (DE) through a simple one-step calcination method and used to degrade 4-chlorophenol (4-CP). Photocatalytic experiments showed that Co-g-C3N4/DE removed up to 98.7% of 4-CP. The doping of Co could capture the photogenerated electrons, thereby reducing the recombination of photocarriers and accelerating the oxidation–reduction reaction of Co3+/Co2+ and H2O2, promoting the generation of OH. Introducing DE improved the aggregation of g-C3N4 and expanded its surface area. Moreover, the Co-g-C3N4/DE composite material exhibited a low metal leaching rate and good reusability throughout the experiments. In addition, based on DFT calculations, the ROS attack mechanism of 4-CP degradation was speculated and calculated. The final product of 4-CP was found to pose a more minor environmental threat, according to the T.E.S.T. In short, the prepared Co-g-C3N4/DE composite realized the capture of photogenerated electrons and the acceleration of photocatalytic reactions, which are expected to solve the challenges in wastewater treatment.

Critical role of zero-valent iron in the efficient activation of H2O2 for 4-CP degradation by bimetallic peroxidase-like.

Peroxidase-like based on double transition metals have higher catalytic activity and are considered to have great potential for application in the field of pollutant degradation. First, in this paper, a novel Fe0-doped three-dimensional porous Fe0@FeMn-NC-like peroxidase was synthesized by a simple one-step thermal reduction method. The doping of manganese was able to reduce part of the iron in Fe-Mn binary oxides to Fe0 at high temperatures. In addition, Fe0@FeMn-NC has excellent peroxidase-like mimetic activity, and thus, it was used for the rapid degradation of p-chlorophenol (4-CP). During the degradation process, Fe0 was able to rapidly replenish the constantly depleted Fe2+ in the reaction system and brought in a large number of additional electrons. The ineffective decomposition of H2O2 due to the use of H2O2 as an electron donor in the reduction reactions from Fe3+ to Fe2+ and from Mn3+ to Mn2+ was avoided. Finally, based on the experimental results of LC-MS and combined with theoretical calculations, the degradation process of 4-CP was rationally analyzed, in which the intermediates were mainly p-chloro-catechol, p-chloro resorcinol, and p-benzoquinone. Fe0@FeMn-NC nano-enzymes have excellent catalytic activity as well as structural stability and perform well in the treatment of simulated wastewater containing a variety of phenolic pollutants as well as real chemical wastewater. It provides some insights and methods for the application of peroxidase-like enzymes in the degradation of organic pollutants.

Synergistic visible light assisted photocatalytic degradation of p-chlorophenol and rifampicin from aqueous solution using a novel g-C3N4 quantum dots incorporated α-MoO3 nanohybrid – Mechanism, pathway and toxicity studies

In this work, a simple g-C3N4 quantum dots enriched MoO3 nanohybrid was formulated for the synergistic photocatalytic degradation of an industrially active organic pollutant, p-chlorophenol (PCP) and a widely prescribed antibiotic, rifampicin (RIF). The nanohybrid was synthesised via a facile ultrasonic assisted hydrothermal method and characterized using various characterization analysis. The efficient Z-scheme charge transfer of the nanohybrid resulted in the elimination of 98% PCP and 89% RIF under visible light with a rate constant of 0.012 and 0.006 min−1 respectively. The photocatalysis was attributed to the formation of both hydroxyl (OH•) and superoxide (O2•-) radicals in the resulting nanohybrid. The intermediates formed in the course of reaction were estimated through gas chromatography-mass spectroscopy/mass spectroscopy (GC-MS/MS) analysis and a suitable degradation pathway was constructed. The structural stability and reusability of the nanohybrid was affirmed through X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis to outweigh the industrial potential of the catalyst, with 85% PCP and 80% RIF removal efficiency after six cycles of degradation. In addition, the mineralization of the pollutants was confirmed by total organic carbon analysis. Further, the toxicity of the drug and the formed intermediates was determined using ecological structure activity relationships (ECOSAR) software. On the whole, this work provides an excellent insight for the development of environment-friendly materials in a large scale for the degradation of water-based pollutants.

Studies on Synthesis, Characterization, and Photocatalytic Activity of TiO2 and Cr-Doped TiO2 for the Degradation of p-Chlorophenol.

TiO2 and Cr-TiO2 nanoparticles (NPs) have been synthesized by the sol-gel method using titanium isopropoxide as the precursor of Titania. The prepared samples were analyzed by employing scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared analyses. Under UV irradiation, the photocatalytic activities of TiO2 and Cr-TiO2 were observed by estimating the % degradation of p-chlorophenol (PCP) as a sample pollutant. The extent of degradation was investigated, varying the catalyst dosage, initial PCP concentration, irradiation time, and solution pH. The experimental results show that efficiency of catalysts initially increases but decreases later on, whereas the % degradation of PCP is the highest at its lowest initial concentration. For TiO2 and Cr-TiO2 NPs at their optimal catalyst dosage of 2.0 g/L, acidic pH, and with UV irradiation for 90 min, the observed % degradation of PCP is 50.23 ± 3.12 and 66.51 ± 2.14%, respectively. Thus, the prepared Cr-TiO2 NPs have enhanced the degradation efficiency of PCP with an irradiation time which is four time less than those reported earlier. From the kinetics analysis, the degradation reaction of PCP is found to follow a pseudo-first-order model and the rate constants are 0.0075 and 0.0122 min-1 for pure TiO2 and Cr-TiO2 NPs, respectively. The present study has further revealed that owing to the lower rate of electron-hole pair recombination, the photocatalytic activity of Cr-TiO2 NPs becomes higher than that of TiO2. Therefore, as viable photocatalytic agents, Cr-TiO2 NPs are suggested to be used also for efficient degradation of other organic pollutants.

Enhanced visible light assisted peroxymonosulfate process by biochar in-situ enriched with γ-Fe2O3 for p-chlorophenol degradation: performance, mechanism and DFT calculation

In this study, a novel γ-Fe2O3/biochar (BFγ) composite by a plant in-situ enrichment and one-step pyrolysis strategy was prepared, which was applied as a photocatalyst to activate peroxymonosulfate (PMS) for the degradation of p-chlorophenol (4-CP) under visible light irradiation (BFγ/PMS/Vis) system. The characterization results exhibited that γ-Fe2O3 with localized carbon doping was evenly embedded in biochar during the pyrolysis. BFγ exhibited better photoresponse properties than biochar (BC) and γ-Fe2O3. The removal efficiency of this system for 4-CP reached 96.41% under optimal conditions. This system showed high removal efficiency with a wide pH range (3.0–13.0) and under conditions of different organic pollutants. It also showed strong resistance to interference with co-existing inorganic ions and humic acid (HA). Electron paramagnetic resonance (EPR) and radical scavenging experiments revealed that the reactive oxygen species (ROS) in this system included SO4-·, ·OH, ·O2- and 1O2. The density functional theoretical (DFT) calculations further revealed the promotion of localized carbon doping in γ-Fe2O3 on electron transfer and photoresponse, including C-O bond (d=1.29 Å), C-Fe bond (d=1.80 Å) and band gap value (Egap < 0.72 eV). This study provides new insights into constructing environmentally-friendly catalysts and the possibility of the solid waste recycling for other wetland plants.

Enhanced Photocatalytic Degradation of P-Chlorophenol by ZnIn2S4 Nanoflowers Modified with Carbon Quantum Dots

The removal of chlorophenol (CP) contaminants from water is a great challenge owing to their natural robustness and the toxic chlorinated by-products generated in degradation processes. In this work, a series of three-dimensional nanoflower-like structured photocatalysts (CQDs/ZnIn2S4-x, x = 1, 2, or 3 wt%) were fabricated via a facile hydrothermal approach. Excellent photocatalytic abilities toward 4-CP degradation under Xe lamp irradiation were achieved over the as-prepared composites. The removal efficiency of total organic carbon for 4-CP on the optimized CQDs/ZnIn2S4-2 was 49.1%, which was 16.0% higher than that of ZnIn2S4. The presence of CQDs could not only be used to adjust controllable band structures for enhancing light absorption, but it could also serve as an electron acceptor to promote the transition of electron–hole pairs. Moreover, a possible degradation mechanism of 4-CP was also proposed according to the analyses of active species, electron paramagnetic resonance characterization, degradation products, and attacked sites. Overall, this work unveils a superior function of an efficient photocatalyst for refractory organic pollutants.

Efficient degradation of p-chlorophenol by N,S-codoped biochar activated perxymonosulfate

The easy preparation of low-cost, highly active, and environment-friendly carbon-based catalysts for wastewater treatment remains a challenge. In this study, we fabricated a biochar codoped with nitrogen and sulfur (NS-BC) as a low-cost and efficient catalyst for peroxymonosulfate (PMS) activation and p-chlorophenol degradation. NS-BC was synthesized by the pyrolysis of sawdust with urea and sulfur powder serving as the nitrogen source and sulfur source, respectively. Due to the large surface area and high defect degree of NS-BC, its catalysis performance for PMS (Kobs=0.8104) was better than those of single-doped (Kobs=0.4177 and Kobs=0.3132) and undoped (Kobs=0.1265) biochar, and it can completely degrade p-chlorophenol within 5 min. The main active substances in the activation process of PMS were elucidated by free radical burst experiments and electron paramagnetic resonance analysis. Superoxide radical and singlet oxygen were the main active species of the system. These catalysts achieve rapid removal of a wide range of organic contaminants over a wide pH range. This work mainly emphasizes that the use of nonmetal-doped biochar to activate PMS to degrade p-chlorophenol, thereby avoiding the environmental harm of metal leaching during catalyst degradation.

Efficient activation of peracetic acid by mixed sludge derived biochar: Critical role of persistent free radicals

Peracetic acid (PAA)-based advanced oxidation processes (AOPs) were increasingly identified as the alternative scheme in wastewater treatment. Cost-effective and easily available catalyst for activation of PAA was in urgent demand for promoting engineering application process. In this study, a new type of biochar catalyst derived from pyrolysis of mixture of primary sludge (PSD) and secondary sludge (SSD) was prepared and showed effective PAA activation ability. The degradation of p-chlorophenol (4-CP) improved with PAA activation by mixed sludge derived biochar (PS-SDBC) than secondary sludge derived biochar (S-SDBC) and primary sludge derived biochar (P-SDBC), and the highest removal efficiency achieved by PS-SDBC with the PSD/SSD ratio of 5/5 (kobs=0.057 1/(M·min), pH 9). Correlation analysis firstly indicated that persistent free radicals (PFRs) rather than chemical composition and material structure dominated PAA activation and organic radicals (RO•) was proved to be the major reactive species through electron paramagnetic resonance (EPR) detection. The mixture of PSD and SSD caused the synergy of inorganic metals and organic matters through pyrolysis processes, resulting in larger specific surface area (SSA) (110.71 m2/g), more abundant electron-donating groups (e.g., C = O, -OH) and massive defects (ID/IG = 1.519) of PS-SDBC than P-SDBC and S-SDBC, which eventually promoted PFRs formation. A fascinating phenomenon was observed in PS-SDBC/PAA system that the active sites of PFRs could be regenerated by RO• attacking onto PS-SDBC, which contributed to the wide pH applicability and continuous stability of PS-SDBC/PAA system in practical wastewater treatment. This study not only significantly deepened the understanding of the reaction mechanism between PAA and biochar, but also provided a potential PAA-based AOPs for micropollutants removal in wastewater.

Fenton-Mediated Chlorophenol Degradation by Iron-Reducing Compounds Isolated from Endophytic Fungi in Atacama Puna Plateau Lecanicillium ATA01

Low-molecular-mass iron-reducing compounds (IRCs) were produced by entomopathogenic endophytic fungi Lecanicillium sp. ATA01 in liquid cultures. The extracellular hydrophilic extract contained three IRCs formed by peptides, iron and phenolate structures with molecular masses of 1207, 567 and 550 Da. These compounds were able to chelate and mediate the reduction of Fe+3 to Fe+2 and oxidized recalcitrant lignin-model substrates such as veratryl alcohol (VA), 2,6-dimethoxyphenol (DMP), and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) with or without hydrogen peroxide. Besides, IRCs can promote the degradation of chlorophenols. The maximal degradation of p-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol was conducted at optimal degradation conditions for IRCs (pH 3.5, iron 100 mM, and H2O2 10 mM). Furthermore, Fenton-like reactions using the synthetic iron chelates DTPA and EDTA and free Fe+2 and Fe+3 were also carried out in order to compare with the reaction mediated by IRCs. The ferric IRCs displayed the ability to enhance the hydroxylation of chlorophenols as a part of a degradation mechanism of the IRC-assisted Fenton reaction. The complexed iron was more efficient than free iron in the Fenton-like reaction, and between them, the fungal chelates were more efficient than the synthetic mill chelates.

The effect of persistent free radicals in sludge derived biochar on p-chlorophenol removal

Sewage sludge pyrolysis can effectively dispose of sludge and obtain sludge-derived biochar (SDBC) as an adsorbent for pollutant removal. Recently, persistent free radicals (PFRs), which have also been detected in many types of biochar, have attracted considerable attention for organic pollutant degradation. Sludge collected from a sewage treatment plant was pyrolyzed into SDBC, which contained a large amount of PFRs, and the resulting SDBC was then applied for the removal of p-chlorophenol. An SDBC dosage of 5 g L−1 was applied for treating 5 mg L−1 of p-chlorophenol; the highest removal efficiency of 90% was achieved at pH 3, and 22% of the initial p-chlorophenol was degraded by the SDBC. Hydroxyl free radicals were observed and contributed to the degradation of p-chlorophenol. The spent SDBC was reused five times after regeneration through the desorption of adsorbed p-chlorophenol. The p-chlorophenol removal efficiency remained constant, but the degradation decreased with increasing reuse cycles, suggesting that the p-chlorophenol degradation efficiency was positively correlated with the intensity of PFRs on SDBC. Further modification of the SDBC sample in HNO3 or NaOH increased the amount of PFRs, and consequently, the degradation of p-chlorophenol under low oxygen conditions, further confirming the crucial role of PFRs in p-chlorophenol degradation. This study provides insights into the application of SDBC, a promising material, for contaminant abatement.

Taping into the Super Power and Magic Appeal of Ultrasound Coupled with Edta on Degradation of P-Chlorophenol by Fe0 Based Advanced Oxidation Processes

Taping into the Super Power and Magic Appeal of Ultrasound Coupled with Edta on Degradation of P-Chlorophenol by Fe0 Based Advanced Oxidation Processes

Enhanced Visible Light Assisted Peroxymonosulfate Process by Biochar In-Situ Enriched with Γ-Fe2o3 for P-Chlorophenol Degradation: Performance, Mechanism and Dft Calculation

Enhanced Visible Light Assisted Peroxymonosulfate Process by Biochar In-Situ Enriched with Γ-Fe2o3 for P-Chlorophenol Degradation: Performance, Mechanism and Dft Calculation

Polystyrene microsphere assisted synthesis of a Co/PEG comodified PbO2 anode and its electrocatalytic oxidation performance

• The Co-PEG-PbO 2 electrode was prepared by PS-assisted electrodeposition. • The electrode possess porous structure and high electrocatalytic performance. • The degradation of p-chlorophenol follows the CE mechanism. Highly performed electrode is one of the key factors affecting the efficiency of oxidation toward organic pollutants. To improve the electrocatalytic performance and stability of PbO 2 electrode, a Co-PEG-PbO 2 electrode modified by Co 2+ ion and polyethylene glycol (PEG 6000) was prepared by polystyrene microspheres assisted electrodeposition combined with surface structure adjustment and active substance doping, and used for the effective degradation of p-chlorophenol in water. The results showed that the Co-PEG-PbO 2 electrode surface was composed of small spherical particles β-PbO 2 , containing a small amount of Co 2 O 3 and PEG, and its grain size (8.985 nm) was the smallest in the same series of electrodes. The electrochemical tests results showed that the oxygen evolution reaction in Na 2 SO 4 solution was a sequential two-step charge transfer process, which was controlled by charge transfer and diffusion. The electrode had smaller oxygen evolution potential (1.40 V), larger exchange current density (j 0 = 1.164 × 10 −4 mA · cm −2 ), smaller charge transfer resistance (0.8778 Ω · cm 2 ) and larger concentration polarization resistance (1.335 Ω · cm 2 ), indicating that the Co-PEG-PbO 2 electrode had better electrocatalytic performance. The degradation of p-chlorophenol was controlled by diffusion and was oxidized by strong oxidizing · OH, which conforms to CE mechanism. Within the same degradation time, the electrode had a higher p-chlorophenol removal efficiency η (97.34%), higher TOC removal efficiency (64.25%), higher mineralization current efficiency (23.45%), and lower cell voltage. The accelerated life test showed that Co-PEG-PbO 2 electrode had the longest service life (280 min), which was 2.8, 1.8 and 2 times of PbO 2 electrode, Co-PbO 2 electrode and PEG-PbO 2 electrode, respectively. The electrocatalytic activity and stability of PbO 2 electrode can be effectively improved by structural adjustment and co-doping with Co 2+ and PEG, which can be used for the effective degradation of p-chlorophenol.

Hetro-nanostructured Se-ZnO sustained with RGO nanosheets for enhanced photocatalytic degradation of p-Chlorophenol, p-Nitrophenol and Methylene blue

• Synthesis of Se-ZnO-RGO nanocomposites by refluxing method. • Photocatalytic degradation and mineralization of phenolic compounds and organic dye from aqueous system. • Recycling and sustainability of SeZG-3 nanocomposite as photocatalyst. • Photodegradation kinetics of p -chlorophenol, p -nitrophenol and methylene blue using SeZG nanocomposites. • Importance of Se and RGO nanosheets in SeZG nanocomposites and Conceivable photocatalytic degradation mechanism. The persistent organic pollutants predominantly phenolic compounds and organic dyes are the hazardous pollutants into the environment, considered as crucial contaminants in aquatic environment as well and cause to different severe detrimental impact on the human being and other living systems. In the present investigation, hetro-nanostructured Se-ZnO incorporated with different weight % of RGO (0, 1, 3, 5 and 8%) coded as SeZG-0, SeZG-1, SeZG-3, SeZG-5 and SeZG-8 nanocomposites were fabricated using a facile and simple refluxing method for the enhanced photocatalytic degradation and complete mineralization of phenolic compounds ( p -Chlorophenol, p -Nitrophenol) and organic dye (methylene blue) via advanced oxidation technique. XRD, Raman, FT-IR, SEM and UV–Vis DRS techniques were used to determine the structural, morphological and optical properties of the synthesized nanocomposites comprehensively, respectively. p -chlorophenol, p -nitrophenol and methylene blue were considered as model organic pollutants in water for the assessment of photocatalytic performance of the SeZG nanocomposites and the mineralization efficiency was obtained 99.02, 98.89 and 99.41% under irradiation of UV light for 105 min, 90 min and 35 min, respectively. The outstanding photocatalytic performance of SeZG nanocomposites revealed by the significant obstruction in the recombination of charge carriers owing to the presence of Se and RGO nanosheets resulting production of additional reactive oxygen species and photodegradation of organic contaminants ( p -chlorophenol, p -nitrophenol and methylene) from water. Finally, photodegradation mechanism is proposed.

Carbon Nitride Supported High-Loading Fe Single-Atom Catalyst for Activation of Peroxymonosulfate to Generate 1 O2 with 100 % Selectivity.

Singlet oxygen (1 O2 ) is an excellent active species for the selective degradation of organic pollutions. However, it is difficult to achieve high efficiency and selectivity for the generation of 1 O2 . In this work, we develop a graphitic carbon nitride supported Fe single-atoms catalyst (Fe1 /CN) containing highly uniform Fe-N4 active sites with a high Fe loading of 11.2 wt %. The Fe1 /CN achieves generation of 100 % 1 O2 by activating peroxymonosulfate (PMS), which shows an ultrahigh p-chlorophenol degradation efficiency. Density functional theory calculations results demonstrate that in contrast to Co and Ni single-atom sites, the Fe-N4 sites in Fe1 /CN adsorb the terminal O of PMS, which can facilitate the oxidization of PMS to form SO5 .- , and thereafter efficiently generate 1 O2 with 100 % selectivity. In addition, the Fe1 /CN exhibits strong resistance to inorganic ions, natural organic matter, and pH value during the degradation of organic pollutants in the presence of PMS. This work develops a novel catalyst for the 100 % selective production of 1 O2 for highly selective and efficient degradation of pollutants.

Oxidative degradation of p-chlorophenol by the persulfate-doped Fe-Mn bimetallic hydroxide, the parametrical significance, and systematical optimization.

Aqueous Fe(II)-catalyzed activation commonly deteriorates the oxidation performance of persulfate (PS) to the treatment of organic contaminants. In this study, a PS-doped layered bimetallic hydroxide (Fe-Mn hydroxide) was synthesized to construct a heterogeneously catalytic system to solve the issue brought by homogeneity. The molar ratio of Fe(II) to Mn(II) and the mass ratio of PS to Fe-Mn hydroxide both had a significant impact on the catalytic degradation of p-CP. Reaction temperatures engaged in the most essential role in influencing the degradation and removal of p-chlorophenol (p-CP). The optimal combination of factors for the preparation of PS-hydroxide and the treatment of p-CP was finally determined by significance analysis. The degradation process was appropriately fitted by the pseudo-first-order kinetic model. The benzene ring in p-CP was broken by PS-hydroxide during the adsorption. The surface modification of PS-hydroxide caused by the valence transition of Mn was beneficial to the adsorption and catalytic degradation of p-CP.