Calculation Of Fukui Functions Research Articles

Electrolyte reactivity on electrode surfaces for active species formation and Reactive Red X-3B degradation in electrochemical treatment of dyeing wastewater.

The pivotal role of electrolytes such as Na2SO4 and NaCl in electrochemical treatment of dyeing wastewater was investigated by comparing recalcitrant Reactive Red X-3B (RRX-3B) degradation rates, active species formation and intermediates generation in a double-chamber cell. It was found that similar reactive oxygen species (ROS) formed in the anodic chamber are •OH and 1O2, in the cathodic chamber is •O2- with different electrolytes, while this is not the case for ROS contribution, RRX-3B degradation kinetic and intermediates. NaCl favored the generation of 1O2, faster decolorization (-N=N- cleavage), and organic intermediates degradation in the anodic chamber. A comparatively faster hydrogenation reduction of -N=N- and higher COD removal with fewer organic categories in Na2SO4 cathodic chamber outperformed those in NaCl cathodic chamber. The RRX-3B degradation pathways were proposed in both chambers based on GC-MS investigations and Fukui function calculations. Atoms Cl, S and N in RRX-3B molecule removals were in the order of R-S>R-N>R-Cl.

Insight into the ferrate(VI)/ozone process: Multiple oxidation systems promote the elimination of electron-deficient pollutants

The utilization of ferrate(VI) (Fe(VI)) is constrained by its limited efficacy in removing electron-deficient pollutants. This study provided insights into the enhanced removal of such pollutants by employing a blend of ozone (O3) and Fe(VI). The removal of electron-deficient pollutants by individual Fe(VI) (50 μM) or O3 (25 μM) ranged from 5 % to 50 % at pH 8.0. The synergistic Fe(VI)/O3 process enhanced the removal to a range of 60 %-95 %, while the pollutants removal rate constant showed a significant increase ranging from 3 to 14 times. The Fe(VI)/O3 process exhibited an increase in total organic carbon removal by 40–90 %. Multiple enhanced oxidation systems were constructed by intermediates derived from the Fe(VI) and O3. The self-decomposition of Fe(VI) released H2O2, which coupled with O3 to form ·OH. Revealed through XPS analysis, the Fe(III) flocs derived from Fe(VI) decomposition contained structures of Fe2O3 and FeOOH. The combined flocs/O3 processes facilitated the production of both ·OH and Fe(IV)/Fe(V). Product analysis and Fukui function calculation demonstrated that, many hydroxylated initial products were exclusively found in the Fe(VI)/O3 process. ·OH initially transforms electron-deficient pollutants into electron-rich products, rendering them more susceptible to electrophilic attack by Fe(IV)/Fe(V). The employment of the Fe(VI)/O3 method demonstrates a concurrent increased production of ·OH and Fe(IV)/Fe(V), presenting a potential resolution for tackling the issue related to stubborn electron-deficient pollutants.

Trace iron induced piezo-polarization field strength on piezo-promoted peroxymonosulfate activation for pollutant degradation

Advanced oxidation processes based on piezo-promoted peroxymonosulfate (PMS) activation in environmental remediation have been widely applied, but the treatment efficiency of pollutants was restricted by sluggish charge separation and low affinity of PMS. Herein, trace iron-doped layered molybdenum disulfide (Fe/MoS2) was used to degrade pollutants by piezo-promoted PMS activation. Real-time reaction site changes in carbamazepine (CBZ) degradation process were predicted by Fukui function calculation of the reaction intermediates, and the possible degradation pathways were given. Through piezoresponse force microscopy and calculation of the adsorption energy, electronic localized functions and Crystal Orbital Hamilton Population, it was verified that Fe doping improves the adsorption of oxygen-containing reactants on MoS2, enhancing the electron delocalization and piezo-polarization field, thus accelerating the piezo-promoted PMS activation kinetics. The degradation efficiency of CBZ on Fe/MoS2 (0.44 min−1) was about 22 times than that of MoS2. Piezo-promoted PMS activation strategy based on Fe/MoS2 still maintains a high removal rate in the treatment of dye and antibiotic pollutants such as ornidazole, rhodamine B, tetracycline, methyl orange, chlortetracycline. This study provides insights into the mechanism by which piezo-promoted PMS activation, and achieving high chemical efficiency for pollutants removal.

A comparative theoretical study on the structural, spectral, microtopology exploration (ELF, RDG, IRI, TDM), NBO and nonlinear optical properties of Red170 from different solvents and substituents

The effect of solvents and substituents on the C.I. Pigment PR170, the best known member of the naphthol red family, is investigated. Both PR170 and its alkoxy derivatives were analyzed using FTIR, 1H NMR and UV–Vis spectroscopy. The study included the evaluation of the average local ionization energy (ALIE), MEP, HOMO-LUMO analysis. The nature of intra- and intermolecular contacts in the crystal structure was also investigated using crystal packing and Hirshfeld surface analysis. Covalent and non-covalent interactions in PR170 were comprehensively described by IRI, RDG and ELF. In addition, Natural Bonding Orbital (NBO) and Fukui function calculations were performed. An analysis of the UV–Vis electronic transitions for different solvents was carried out, providing insight into the charge transfer processes within both PR170 and its derivatives. In particular, the research indicated a CT-type excitation at the S2 level during the hole-electron transfer analysis. The NLO results showed that PR170 is a promising candidate for nonlinear optical materials.

Insight into photocatalytic chlortetracycline degradation by WO3/AgI S-scheme heterojunction: DFT calculation, degradation pathway and electron transfer mechanism

The construction of S-scheme heterojunction with excellent redox ability holds promising prospects for photocatalytic environment remediation. However, the rationally design of the heterojunction interface to achieve efficient charge transfer still faces challenges. In this study, we fabricated a tight-contacted S-scheme heterojunction by in situ anchoring AgI nanoparticles onto WO3 nanoplates. The significant difference in Fermi energy levels between WO3 and AgI results in the formation of a space charge region around the interface and bending of the energy band, facilitating directional migration and spatial separation of charge carriers. This contributes to enhanced generation of superoxide radicals (•O2−) and holes (h+) active species, leading to a significant increase in chlortetracycline (CTC) degradation rate. The apparent rate constant for CTC removal using the WO3/AgI (WA-2) is approximately 15 times higher than that observed for pure WO3. Furthermore, WA-2 exhibits universal degradation effects on tetracycline (TC) and oxytetracycline (OTC). Molecular dynamics (MD) simulation reveals the synergistic adsorption effect of WO3 and AgI on CTC and reactive oxygen species molecules. Based on Fukui function calculation of CTC molecules and degradation intermediates, liquid chromatography-mass spectrometry (LC-MS) analysis, photocatalytic degradation pathway over WO3/AgI was determined to be sequential demethylation followed by dechlorination and decarbonylation. These findings provide valuable insights into high-performance S-scheme heterojunctions interface design and elucidation of pollutant degradation mechanism.

Z-scheme γ-Fe2O3/g-C3N4 in Photo-Fenton reaction for oxytetracycline degradation: Mechanism study and DFT calculation

With the urbanization and industrialization of the world, the pollution of water due to the misuse of antibiotics is increasing. In this study, a Z-scheme γ-Fe2O3/g-C3N4 composite photocatalyst was prepared, and the removal efficiency of oxytetracycline (OTC) reached 85.7% within 60 min under the Photo-Fenton reaction system higher than that of g-C3N4 and γ-Fe2O3. The composite has great anti-interference capability and sustainability, and the recyclability was demonstrated using hysteresis return lines data. The photoelectrochemical characterization was analyzed to investigate the effect of the building of Z-scheme heterojunction on the photogenerated carrier separation efficiency. The charge behavior of heterojunction interfaces was probed in conjunction with DFT calculations, and differential charge maps were used to visualize charge distributions to analyze possible charge transfer pathways. In addition, the active substances in the system were identified by ESR data and capture experiments. The results showed that ·OH was the dominant active substance for OTC degradation. Meanwhile, LC-MS data combined with Fukui function calculations led to the derivation of a possible degradation pathway dominated by ·OH. This research provides a reference for subsequent studies of non-homogeneous Photo-Fenton systems and offers a viable option for mitigating OTC pollution in water bodies.

(E)-2-Benzylidenecyclanones: Part XIX. Reaction of (E)-2-(4'-X-Benzylidene)-1-tetralones with Cellular Thiols: Comparison of Thiol Reactivities of Open-Chain Chalcones and Their Six- and Seven-Membered Cyclic Analogs.

Non-enzyme-catalyzed thiol addition onto the α,β-unsaturated carbonyl system is associated with several biological effects. Kinetics and diastereoselectivity of non-enzyme catalyzed nucleophilic addition of reduced glutathione (GSH) and N-acetylcysteine (NAC) to the six-membered cyclic chalcone analogs 2a and 2b were investigated at different pH values (pH 3.2, 7.4 and 8.0). The selected compounds displayed in vitro cancer cell cytotoxicity (IC50) of different orders of magnitude. The chalcones intrinsically reacted with both thiols under all incubation conditions. The initial rates and compositions of the final mixtures depended both on the substitution and the pH. The stereochemical outcome of the reactions was evaluated using high-pressure liquid chromatography with UV detection (HPLC-UV). The structures of the formed thiol-conjugates and the retro-Michael products (Z)-2a and (Z)-2b were confirmed by high-pressure liquid chromatography-mass spectrometry (HPLC-MS). Frontier molecular orbitals and the Fukui function calculations were carried out to investigate their effects on the six-membered cyclic analogs. Data were compared with those obtained with the open-chain (1) and the seven-membered (3) analogs. The observed reactivities do not directly relate to the difference in in vitro cancer cell cytotoxicity of the compounds.

Interfacial engineering between carbon vacancies modified graphitic carbon nitride and CoAl-LDH formed heterojunctions for improved photocatalytic performance: Degradation pathway, DFT calculations, and mechanism insights

The construction of green, low-cost heterojunctions with interfacial interaction is crucial to enhance their photocatalytic performance and broaden their utility in practical applications. Here, we prepared CoAl-LDH/Carbon Nitride with carbon vacancies (Cv-CN) heterojunction by electrostatic self-assembly strategy to explore its photocatalytic properties. 30 wt% CoAl-LDH/70 wt% Cv-CN (CCN-2) exhibited the optimal photocatalytic degradation performance after 120 min of light exposure, with a degradation efficiency of 93.1 %. Fukui function calculations, in conjunction with LC-MS/MS analysis, were employed to explore potential degradation pathways during the photocatalytic degradation of tetracycline. The photocatalytic performance of CoAl-LDH/Cv-CN heterojunction was further analyzed by photocatalytic hydrogen production experiments, and after five hours, the hydrogen production rate of CCN-2 was 2515 µmol/g (Cv-CN: 1554 µmol/g, CoAl-LDH: hardly produced any hydrogen). According to the experimental results and data analysis, an effective charge-carrier separation and transfer pathway is established through the interfacial engineering between CoAl-LDH and Cv-CN forming the heterojunction at the interface of CoAl-LDH and Cv-CN. The heterojunction structure formed by interfacial engineering between CoAl-LDH and Cv-CN enables effective photocatalytic removal of antibiotics and hydrogen production providing new insights into the treatment of aqueous environments and clean energy production.

Combined experimental and quantum computational studies on 5-Fluorouracil salicylic acid cocrystal: Assessment on anti-breast cancer potential through docking simulation

5-fluorouracil salicylic acid (5FUSA) cocrystal was synthesised via mechanochemical and solution evaporation technique and spectroscopic experiments and theoretical research were conducted. Methods for the experiments included XRD, FTIR, and UV spectroscopy. Following that, 5FUSA was the subject of quantum chemistry investigations employing the DFT/B3LYP/6–311++G (d, p) basis level. First, the resultant simulated XRD pattern was compared to the relevant experimental pattern. The estimated FT-IR frequencies were gathered from the same level of theory and compared to the experimental data. To learn more about the reactive properties of the 5FUSA, the molecular electrostatic potential plot was generated, and Fukui function calculations were also performed. In order to examine intramolecular interactions and verify the bioactivity of the 5FUSA molecule, the natural bond orbital study was also carried out. We examined the UV–Vis absorption wavelengths (λ) via theoretical (TD-DFT) and experimental methods. The non-linear optical properties were identified, and it was discovered that it had three times the NLO activity of urea. The inter- and intramolecular interactions of the 5FUSA were explored using the Hirshfeld surface and finger print approaches. At various temperatures thermodynamic parameters were calculated and topological analyses were conducted using the (ELF, LOL, and RDG). The anticancer activity of 5FUSA cocrystal was studied using molecular docking and the docking scores ranges between -8.1 to -9.0 Kcal/mol against breast tumor proteins.

Condensed Fukui function and experimental evaluation of the corrosion inhibition properties of some antipyrinyl‐imidazotriazole and their derivatives for copper in an acidic environment

AbstractThe effectiveness of synthesized antipyrinyl‐imidazotriazole and its derivatives as inhibitors for the corrosion of copper alloy in 0.5 M H2SO4 solution was tested using weight loss, electrochemical impedance spectroscopy (EIS) and potentiodyanmic polarization techniques. The generated results confirmed that the tested compounds have strong inhibition efficiencies for the protection of the corrosion of copper alloy in 0.5 M H2SO4. Maximum inhibition efficiencies (IEs) evaluated from electrochemical measurements at inhibitor's concentrations of 0.040 g/L were 85% (5‐(4‐Antipyrinyl)‐3H‐imidazo[1,2‐b][1,2,4]triazole), 60% (6‐Antipyrinyl‐imidazo[2,1‐b]thiazole) and 72% (2‐Antipyrinyl‐7‐ethoxy‐imidazo[2,1‐b]benzothiazole). It was observed that the inhibition efficiency was strongly influenced by the flow rate of the solution and was reduced to 79 (5‐(4‐Antipyrinyl)‐3H‐imidazo[1,2‐b][1,2,4]triazole), 60% (6‐Antipyrinyl‐imidazo[2,1‐b]thiazole), and 44% (2‐Antipyrinyl‐7‐ethoxy‐imidazo[2,1‐b]benzothiazole) at an agitation speed of 400 rpm. EI from weight loss was comparable with those from PDP of mixed‐type inhibition style and EIS of diffusion model. The low inhibition efficiency for 6‐Antipyrinyl‐imidazo[2,1‐b]thiazole was significantly enhanced from 60% to 90% through a synergistic effect of 0.0001 M KI. The Temkin and Frumkin isotherms indicate the physical adsorption of inhibitors on copper surface. Condensed Fukui function calculations reveal a common center for electrophilic attacks in the three molecules: the nitrogen in the bridged pyrrole rings (labeled as N11).

Rational construction of visible-light-driven perylene diimides/Fe2O3@C derived from MIL-88A (Fe) heterojunction with S-scheme electron transfer pathway to activate peroxymonosulfate for degradation of antibiotics

The novel composite photocatalytic material perylene diimides/Fe2O3@C (PDIs/Fe2O3@C) was constructed by a simple hydrothermal-calcination method and an oil bath method. 20 % PDIs/Fe2O3@C displayed a 16.4-fold increase in the rate of tetracycline (TC) removal over Fe2O3@C at 8 min. The main factor that enhanced photocatalytic performance was due to the combination of PDIs with Fe2O3@C, which effectively improved the phenomenon during the self-assembly of highly agglomerative PDIs, increased the specific surface area of Fe2O3@C, exposed more reaction sites, and promoted the activation of peroxymonosulfate (PMS) by Fe2+/Fe3+; and secondly, the composite of two different materials, both organic and inorganic, which effectively promoted the photogenerated electron transfer and the separation of electron-hole pairs, the a new S-scheme electron transport pathway is formed, which effectively promoted the photogenerated electron transfer as well as the e−-h+ separation, which was more favorable for the activation of PMS. The whole reaction pathway and product toxicity were thoroughly evaluated by Fukui function calculations, Liquid Chromatograph Mass Spectrometer (LC-MS), and Toxicity Estimation Software Tool (T.E.S.T.) simulation results, which demonstrated the rationality of the degradation pathway and the greatly reduced product toxicity. Moreover, the composites were effective and versatile for all other antibiotics (chlortetracycline (CTC), ciprofloxacin (CIP) and sulfadiazine (SDZ)). As an advanced oxidation process, the activation of PDIs/Fe2O3@C under visible light shows its potential application in pollutant degradation, which provides new perspectives and ideas for further effective treatment of real wastewater.

Dark blue azo dye degradation by the electro-Fenton process and reaction mechanism prediction via theoretical Fukui function analysis

The electro-Fenton process, based on a new electrode combination, was investigated for the degradation of dark blue azo dye. Fukui function calculations were performed to propose a theoretical degradation mechanism.

In-situ Salen-type ligand formation-driven of a heterometallic Cu(II)-Hg(II) complex: Synthetic update, crystallographic features, DFT calculations, and unveil antimicrobial profiles

This article vividly describes the synthesis and structural characterization of one 6-Bromo-2-hydroxy-3-methoxybenzaldehyde ligand involving heteronuclear complex, [Cu(L)Hg(Cl)2]. X-ray single-crystal determined the complex crystal structure and characterized it by various physical methods, including elemental, FT-IR, Raman, PXRD, UV–vis, NMR, and SEM-EDX techniques. X-ray diffraction analysis reveals that the compound adopts a monoclinic space group Cc during crystallization. The crystal structure exhibits unique supramolecular interactions, like intermolecular C-H∙∙∙π H-bonding and X-bonding (X = Halogen) between Br(1) and Br(2) atoms. Hirshfeld surfaces (HS) and 2-D fingerprint plots confirm significant H…Cl (21.9 %) contacts. Further, dispersion energy dominates due to Br atoms' higher electron/electron cloud. The complex underwent DFT calculations based on the Gaussian software package at B3LYP, HF, and M062x levels, utilizing the lanl2dz, sdd, and def2tzvp basis sets. The HOMO-LUMO, ESP, Global reactivity, Interaction energy and energy frameworks, and Fukui function investigated the complex properties in a multidimensional spectrum. The complex showed promising NLO activity, which has broad technological applications. Fukui function calculation identifies regions prone to nucleophilic (Nu-) and electrophilic (E+) attacks. The complex and synthetic components were examined for antimicrobial function against Gram+ve and Gram-ve bacterial and fungal strains. Molecular docking (MD) and Protein-Ligand Interaction Profilers (PLIP) further support the antimicrobial findings.

Visible light-driven LaFeO3-biochar composites for removal of sulfamethoxazole by enhanced electron transfer coupled with peroxymonosulfate

In this study, we prepared a novel biochar and LaFeO3-bonded nanosphere composite (LFBC) using a co-precipitation-pyrolysis method for the degradation of sulfamethoxazole (SMX). Under visible light conditions, LFBC-activated peroxymonosulfate (PMS) completely removed SMX within 25 min with rate constants 23 and 59 times higher than those of LaFeO3 and biochar, respectively. Both free radical and non-free radical pathways participated in the SMX degradation process, with the non-free radical pathway playing a primary role. It is noteworthy that the interaction between LaFeO3 and Biochar facilitated electron transfer and active sites, promoted the redox cycle of Fe3+/Fe2+, and greatly enhanced the catalytic performance of the composites. Degradation pathway and toxicity evaluation of pollutant removal processes in LFBC/PMS/vis systems based on intermediate identification and Fukui function calculations. This work proved the excellent synergistic performance of LFBC in light utilization and PMS activation, providing a potential utilization for efficient treatment of antibiotic wastewater and antibiotic-resistant bacteria.

Spectroscopic, Quantum Chemical and Molecular Docking Studies on N-(9H-Purin-6-yl) Benzamide: A Potent Antimalarial Agent

This study presents a comprehensive analysis of N-(9H-purin-6-yl) Benzamide (NPB) using a combination of Density Functional Theory (DFT) calculations and experimental techniques. The molecular configuration of NPB was optimized using DFT/B3LYP method employing the 6-311++G (d,p) basis set. The fundamental frequencies were calculated and assigned, which agree well with the experimental results. The UV-Vis spectroscopic analyses, HOMO-LUMO energy gap assessment, Molecular Electrostatic Potential calculation, and Mulliken charge analysis, Fukui function calculation and Natural bond orbital analysis were performed for the NPB molecule. The UV-Visible spectral analysis, which predicts the transition of bonding and anti-bonding π-electrons from the purine ring to the aromatic ring of the NPB molecule. A smaller energy gap in the HOMO-LUMO analysis reveals that the NPB molecule is more reactive and Mulliken atomic charge distribution analysis indicates that the carbon atoms are highly influenced by their substituents. Natural Bond Orbital (NBO) analysis was employed to investigate the bonding within the NPB molecule. The Fukui function analysis indicates that the biological activity of the NPB molecule. In order to analyze the structure of NPB molecule, the thermodynamic properties in the temperature range 100–1000 K were obtained by thermodynamic analysis software SHERMO calculator. The molecular docking analysis was carried out for antimalarial proteins (5ZNC, 2BMA, 7E27, 7E26) using auto-docking simulations. This computational method confirms the bioactivity and drug-likeness parameters of the NPB molecule. The molecular docking results predicts the formation of hydrogen bonds between the ligand (NPB) and the protein receptors. Based on these findings, this study establishes that the distinctive methodology applied to identify NPB molecule as a potential candidate for an antimalarial drug designing, which is suitable for in vivo and in vitro investigations.

O2 plasma-modified carbon nanotube for sulfamethoxazole degradation via peroxymonosulfate activation: Synergism of radical and non-radical pathways boosting water decontamination and detoxification

Sulfamethoxazole (SMX), a widely used antibiotic, has triggered increasing attention due to its extensive detection in wastewater effluent, causing serious ecological threats. Herein, a carbon-based heterogeneous catalyst was developed by the O2 plasma-etching process, regulating oxygen-containing functional groups (OFGs) and defects of carbon nanotubes (O-CNT) to activate peroxymonosulfate (PMS) for highly efficient SMX abatement. Through adjusting the etching time, the desired active sites (i.e., C=O and defects) could be rationally created. Experiments collectively suggested that the degradation of SMX was owing to the contribution of synergism by radical (•OH (17.3%) and SO4•– (39.3%)) and non-radical pathways (1O2, 43.4%), which originated from PMS catalyzed by C=O and defects. In addition, the possible degradation products and transformation pathways of SMX in the system were inferred by combining the Fukui function calculations and the LC-MS/MS analysis. And the possible degradation pathway was effective in reducing the environmental toxicity of SMX, as evidenced by the T.E.S.T. software and the micronucleus experiment on Vicia faba root tip. Also, the catalytic system exhibited excellent performance for different antibiotics removal, such as amoxicillin (AMX), carbamazepine (CBZ) and isopropylphenazone (PRP). This study is expected to provide an alternative strategy for antibiotics removal in water decontamination and detoxification.

Spectroscopic investigations, quantum chemical, molecular docking and drug likeness studies of t-butyl-3,4,5-trimethyl-2-pyrrole carboxylate

The geometrical structure of t‑butyl‑3,4,5-trimethyl-2-pyrrole carboxylate (TBTPC) was computed by DFT calculations using the B3LYP method and the 6–311++G(d,p) basis set using the Gaussian 09 software. Vibrational wavenumbers were assigned using the VEDA 4.0 program. Natural bond orbital (NBO) analysis predicts the hyper-conjugative interaction and stabilization interaction of the TBTPC compound. HOMO, LUMO, and other molecular properties were calculated. The density of states (DOS) spectrum was also predicted. The ultraviolet-visible spectrum has been experimentally and theoretically validated and simulated. The electrophilic and nucleophilic reactive sites of the TBTPC molecule were determined using the Fukui function calculation and the molecular electrostatic potential (MEP) surface. Molecular docking analysis of the TBTPC ligand helps to investigate its inhibitory nature against Lysine-specific demethylase 1A (LSD1), α-amylase, BCL-1, and monoamine oxidase (MAO). From the molecular docking results, TBTPC has promising inhibition activity against gastric cancer.

Simultaneously Achieving Fast Intramolecular Charge Transfer and Mass Transport in Holey D-π-A Organic Conjugated Polymers for Highly Efficient Photocatalytic Pollutant Degradation.

Simultaneously realizing efficient intramolecular charge transfer and mass transport in metal-free polymer photocatalysts is critical but challenging for environmental remediation. Herein, we develop a simple strategy to construct holey polymeric carbon nitride (PCN)-based donor-π-acceptor organic conjugated polymers via copolymerizing urea with 5-bromo-2-thiophenecarboxaldehyde (PCN-5B2T D-π-A OCPs). The resultant PCN-5B2T D-π-A OCPs extended the π-conjugate structure and introduced abundant micro-, meso-, and macro-pores, which greatly promoted intramolecular charge transfer, light absorption, and mass transport and thus significantly enhanced the photocatalytic performance in pollutant degradation. The apparent rate constant of the optimized PCN-5B2T D-π-A OCP for 2-mercaptobenzothiazole (2-MBT) removal is ∼10 times higher than that of the pure PCN. Density functional theory calculations reveal that the photogenerated electrons in PCN-5B2T D-π-A OCPs are much easier to transfer from the donor tertiary amine group to the benzene π-bridge and then to the acceptor imine group, while 2-MBT is more easily adsorbed on π-bridge and reacts with the photogenerated holes. A Fukui function calculation on the intermediates of 2-MBT predicted the real-time changing of actual reaction sites during the entire degradation process. Additionally, computational fluid dynamics further verified the rapid mass transport in holey PCN-5B2T D-π-A OCPs. These results demonstrate a novel concept toward highly efficient photocatalysis for environmental remediation by improving both intramolecular charge transfer and mass transport.

Visible-Light-Driven Peroxymonosulfate Activation for Accelerating Tetracycline Removal Using Co-TiO2 Nanospheres

Heterogeneous catalysts have been widely used for peroxymonosulfate (PMS) activation to remove persistent contaminants in water. This study successfully prepared cobalt-doped TiO2 using a simple two-step approach for activating PMS to remove tetracycline (TC). The batch experiments showed complete TC degradation within 25 min caused by Co-TiO2 (0.1 g/L) activation of PMS (1 mM) under visible light. The system also demonstrated excellent catalytic efficiency in various water environments, such as artificial seawater, tap water, and wastewater. According to the radical capture tests and electron spin resonance analysis, the contribution of active species involved in the degradation of TC with the Vis/Co-TiO2/PMS system were in the following order: 1O2> SO4•−> O2•−> •OH. The possible TC degradation pathway was proposed using intermediate identification and Fukui function calculation. This study provides a promising method toward organic pollutants degradation and provides a novel perspective on the rational design of competent and stable catalysts.

Adsorption and photocatalytic degradation process of oxytetracycline using mesoporous Fe-TiO2 based on high-resolution mass spectrometry

In this study, the adsorption and photocatalytic degradation of oxytetracycline (OTC) were systematically investigated using different metal-doped anatase-phase mesoporous TiO2 nanocatalysts (M−TiO2, M = Fe, Co, Ni, Cr). The results showed that doping with different metals had a significant effect on the ability of TiO2 to adsorb and degrade OTC. Comparing the photoelectric properties of four photocatalysts (Fe-TiO2, Co-TiO2, Ni-TiO2 and Cr-TiO2), it was observed that the mutual synergy between the separation ability of the photogenerated carriers and the adsorption ability of pollutants was the fundamental reason for the excellent photocatalytic performance of Fe-TiO2. The relative intensities of the high-resolution mass spectrometry (HRMS) peaks were used to track and analyse the degradation products of pollutants at different adsorption or light-irradiation times during the photocatalytic process. The ability of the pollutants to undergo dark-state adsorption significantly influenced their degradation paths and products. The possible mechanism of the photocatalytic decomposition of pollutants using Fe-TiO2 along different paths was proposed according to the Fukui function calculation and MS results. To the best of our knowledge, this is the first time that quantitative HRMS results have been used to assess the degradation pathways of pollutants.