Revealing the Multifunctional Electrocatalysis of Indium-Modulated Phthalocyanine for High-Performance Lithium-Sulfur Batteries

The sluggish kinetics of complicated multiphase conversions and the severe shuttling effect of lithium polysulfides(LiPSs)significantly hinder the applications of Li-S battery,which is one of the most promising candidates for the next-generation energy storage system.Herein,a bifunctional electrocatalyst,indium phthalocyanine self-assembled with carbon nanotubes(InPc@CNT)composite material,is proposed to promote the conversion kinetics of both reduction and oxidation processes,demonstrating a bidirectional catalytic effect on both nucleation and dissolution of Li_(2)S species.The theoretical calculation shows that the unique electronic configuration of InPc@CNT is conducive to trapping soluble polysulfides in the reduction process,as well as the modulation of electron transfer dynamics also endows the dissolution of Li_(2)S in the oxidation reaction,which will accelerate the effectiveness of catalytic conversion and facilitate sulfur utilization.Moreover,the InPc@CNT modified separator displays lower overpotential for polysulfide transformation,alleviating polarization of electrode during cycling.The integrated spectroscopy analysis,HRTEM,and electrochemical study reveal that the InPc@CNT acts as an efficient multifunctional catalytic center to satisfy the requirements of accelerating charging and discharging processes.Therefore,the Li-S battery with InPc@CNT-modified separator obtains a discharge-specific capacity of 1415 mAh g^(-1)at a high rate of 0.5 C.Additionally,the 2 Ah Li-S pouch cells deliver 315 Wh kg^(-1)and achieved 80%capacity retention after 50 cycles at 0.1 C with a high sulfur loading of 10 mg cm^(-2).Our study provides a practical method to introduce bifunctional electrocatalysts for boosting the electrochemical properties of Li-S batteries.

Pyrolysis of Copper Phthalocyanine as Non-noble Metal Electrocatalysts for Oxygen Reduction Reaction

We investigated the relationship between oxygen reduction reaction(ORR)activity and the pyrolysis temperature(650-850℃)of CuPc in alkaline solution.The highly active sites were formed through the decomposition of CuPc or Cu-N_(4) structure after releasing 4-nitrophthalonitrile.Cu-Nx incorporated with carbon were the main active sites.The XPS measurement results show that,at lower temperature,the contents of pyridinic-N and pyrrolic-N account for the most of the total N.As the temperature is higher than 750℃,the content of graphitic N(26.11%)increases and pyridinic-N(58.81%)becomes the dominant specie.When the temperature is higher than 850℃,the content of graphitic N increases remarkably and becomes the dominant species.Moreover,the specific surface areas decrease with increased pyrolysis temperature.Benefiting from the synergistic effect,the pyrolysis temperature at 750℃of CuPc displays superior electrocatalytic properties.The obtained results reveal that the fabricated non-noble metal catalysts can be used as low-cost,efficient catalyst for water splitting ORR in metal-air batteries and fuel cells.

Assessing the dynamics of O_(2) desorption from cobalt phthalocyanine by in situ electrochemical scanning tunneling microscopy

We report here the in situ electrochemical scanning tunneling microscopy(ECSTM) study of cobalt phthalocyanine(CoPc)-catalyzed O_(2) evolution reaction(OER) and the dynamics of CoPc-O_(2) dissociation.The self-assembled CoPc monolayer is fabricated on Au(111) substrate and resolved by ECSTM in 0.1 M KOH electrolyte.The OH^(-)adsorption on CoPc prior to OER is observed in ECSTM images.During OER,the generated O_(2) adsorbed on Co Pc is observed in the CoPc monolayer.Potential step experiment is employed to monitor the desorption of OER-generated O_(2) from CoPc,which results in the decreasing surface coverage of CoPc-O_(2) with time.The rate constant of O_(2) desorption is evaluated through data fitting.The insights into the dynamics of Co-O_(2) dissociation at the molecular level via in situ imaging help understand the role of Co-O_(2) in oxygen reduction reaction(ORR) and OER.

Indirect Electroanalysis of 3-Methyl-4-Nitrophenol in Water Using Carbon Fiber Microelectrode Modified with Nickel Tetrasulfonated Phthalocyanine Complex

Electrochemical detection of 3-methyl-4-nitrophenol (MNP) in direct phenol oxidation occurs at high potentials and generally leads to progressive passivation of the electrochemical sensor. This study describes the use of a carbon fiber microelectrode modified with a tetrasulfonated nickel phthalocyanine complex for the detection of MNP at a lower potential than that of direct phenol oxidation. The MNP voltammogram showed the presence of an anodic peak at -0.11 V vs SCE, corresponding to the oxidation of the hydroxylamine group generated after the reduction of the nitro group. The effect of buffer pH on the peak current and SWV parameters such as frequency, scan increment, and pulse amplitude were studied and optimized to have better electrochemical response of the proposed sensor. With these optimal parameters, the calibration curve shows that the peak current varied linearly as a function of MNP concentration, leading to a limit of detection (LoD) of 1.1 μg/L. These results show an appreciable sensitivity of the sensor for detecting the MNP at relatively low potentials, making it possible to avoid passivation phenomena.

Iron(Ⅲ) phthalocyanine chloride-catalyzed oxidation–aromatization of α,β-unsaturated ketones with hydrazine hydrate: Synthesis of 3,5-disubstituted 1H-pyrazoles

We have developed an iron（III） phthalocyanine chloride‐catalyzed oxidation–aromatization ofα,β‐unsaturated ketones with hydrazine hydrate. Various 3,5‐disubstituted 1H‐pyrazoles were obtained in good to excellent yields. This method offers several advantages, including room‐tem‐perature conditions, short reaction time, high yields, simple work‐up procedure, and use of air as an oxidant. The catalyst can be recovered and reused five times without loss of activity.

Influence of dye molecular structure on electron transfer in 2,9,16,23-tetracarboxy zinc phthalocyanine sensitized solar cell

2, 9, 16, 23-tetracarboxy zinc phthalocyanine （ZnTCPc） is synthesized and characterized by physicochemical and theoretical methods and it is used as a photosensitizer in dye-sensitized solar cells （DSSC）. The excited lifetime, band gap and frontier orbital distribution of ZnTCPc are investigated by fluorescence spectra, cyclic voltammetry and quantum calculation. The results show that the excited lifetime and band gap are 0. 1 ns and 1.81 eV, respectively. Moreover, it is found that the highest occupied molecular orbital （HOMO） location is not shared by both the zinc metal and the isoindoline ligands, and the lowest unoccupied molecular orbital（LUMO） location does not strengthen the interaction coupling between ZnTCPc and TiO：. As a result, the ZnTCPc-DSSC gains a short-circuit current density of 0. 147 mA/cm2, an open-circuit photovoltage of 277 mV, a fill factor of 0. 51 and an overall conversion efficiency of 0. 021%.

Synthesis and Characterization of Novel Mesogenic octa-Substituted Phthalocyanines

Synthesis and separation of asymmetrically octa-substituted phthalocyanines （Pcs） derivatives obtained by cyclotetramerization of two different phthalonitriles （Pns） precursors is described. The phthalonitriles were designed to have different polarity to enable successful chromatographic isolation. The side-chains was designed to lie perpendicular to the plane of the macrocycle via ketal link. It was hoped that the obtained materials would exhibit enhanced solubility and less columnar aggregation both in solution and in the solid state. The preparation of the ketal compounds （2,2-didodecyl- 1,3-benzodioxoles ） with was performed according to Cole method in which catechol and the didodecyl ketone were refluxed in toluene solution in the presence of a catalytic amount of p-toluene sulphonic acid （PTSA）. The resultant water was removed by azeotropic distillation using a Dean-Stark trap. 2,2-didodecyl-l,3-benzodioxoles was brominated then cyanated as described in literature to give the desired phthalonitrile. The other phthalonitrile （4,5-bis（1＇,4＇,7＇,10＇-tetraoxaundecyl） phthalonitrile was obtained also as described in literature. The structures of the obtained isomers were confirmed by spectroscopic methods. Optical microscopy and differential scanning calorimetry （DSC） measurements revealed that two of the obtained derivatives display hexagonal and rectangular columnar liquid crystalline phases （Dhd＆Drd） over a wide temperature range.

Optical and Electrochemical Properties of Non-Peripheral Thioaryl-Substituted Subphthalocyanine as Precursors for Dye-Sensitizer to Develop Photovoltaic Cells

Phthalocyanines-related compounds, subphthalocyanines, are the homologues consisting of three isoindole units with boron as the center. The absorption maximum of subphthalocyanines, called the Q band, appears around 560 - 630 nm, which is shifted by approximately 100 nm to shorter wavelengths compared to phthalocyanines. Subphthalocyanines are used as precursors to prepare unsymmetric phthalocyanines for ring enlargement reaction. In this decade, phthalocyanines are used for dye-sensitized solar cells (DSSCs), which require strong absorption of far-red light between 700 and 850 nm because of their highly efficiency. Non-peripheral thioaryl-substituted phthalocyanines have been synthesized. They show near-infrared absorption around 780 - 870 nm and have excellent electron transfer properties. However, their lack of affinity to basal plats inhibits their use as DSSC photosensitizer. Therefore, to synthesize unsymmetrical non-peripheral thioaryl-substituted phthalocyanines possessing good affinity to basal plates, the authors prepared subphthalocyanines having thioaryl substituents as precursors. Spectroscopic properties and electron transfer abilities to synthesize non-peripheral thioaryl-substituted subphthalocyanines were estimated using cyclic voltammetry. The Q band of non-peripheral thioaryl-substituted subphthalocyanines shows around 650 nm shifted to longer wavelength by 86 nm in comparison to subphthalocyanine. The compounds show many reduction potentials. They are acceptable electrons in the subphthalocyanine ring, meaning that the compounds have good electron transfer properties.

Operando HERFD-XANES and surface sensitive Δμ analyses identify the structural evolution of copper(Ⅱ) phthalocyanine for electroreduction of CO_(2)

The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,conventional in situ X-ray spectroscopy plays a limited role in tracing the underlying dynamic structural changes in catalysts active sites.Herein,operando high-energy resolution fluorescence-detected X-ray absorption spectroscopy was used to precisely identify the dynamic structural transformation of well-defined active sites of a representative model copper(Ⅱ)phthalocyanine catalyst which is of guiding significance in studying single-atom catalysis system.Comprehensive X-ray spectroscopy analyses,including surface sensitive△μspectra which isolates the surface changes by subtracting the disturb of bulk base and X-ray absorption near-edge structure spectroscopy simulation,were used to discover that Cu species aggregated with increasing applied potential,which is responsible for the observed evolution of C_(2)H_(4).The approach developed in this work,characterizing the active-site geometry and dynamic structural change,is a novel and powerful technique to elucidate complex catalytic mechanisms and is expected to con tribute to the rational design of highly effective catalysts.

Zinc phthalocyanine as an efficient catalyst for halogen-free synthesis of formamides from amines via carbon dioxide hydrosilylation under mild conditions

The combination of a zinc phthalocyanine(ZnPc)catalyst and a stoichiometric amount of dimethyl formamide(DMF)provided a simple route to formamide derivatives from amines,CO2,and hydrosilanes under mild conditions.We deduced that formation of an active zinc‐hydrogen(Zn‐H)species promoted hydride transfer from the hydrosilane to CO2.The cooperative activation of the Lewis acidic ZnPc by strongly polar DMF,led to formation of activated amines and hydrosilanes,which promoted the chemical reduction of CO2.Consequently,the binary ZnPc/DMF catalytic system showed excellent yields and superior chemoselectivity,representing a simple and sustainable pathway for the reductive transformation of CO2into valuable chemicals as an alternative to conventional halogen‐containing process.

A bipolar metal phthalocyanine complex for sodium dual-ion battery

Dual-ion batteries(DIBs) have attracted immense interest as a new generation of energy storage device due to their low cost,environmental friendliness and high working voltage.However,developing DIBs using organic compounds as active electrode materials is in its infancy.Herein,we first report a bipolar and self-polymerized Cu phthalocyanine(CuTAPc) as an electrode material for sodium-based DIBs(SDIBs).Benefitting from the bipolar property,CuTAPc could serve as the cathode or anode material to construct metal sodium-based or metal sodium-free SDIB(cell 1 or 2) by coupling with sodium anode or graphite cathode,respectively.As a result,cell 1 displays a high discharge capacity of 195.7 mAh g^(-1) at 50 mA g^(-1) and a high reversible capacity of 57 mAh g^(-1) over 2500 cycles at 1 A g^(-1),and cell 2 shows a high energy density of 324 Wh kg^(-1) and a high power density of 7481 W kg^(-1).Subsequently,the proposed binding mechanism and the bipolar reactivity of CuTAPc have been revealed by the detailed reaction kinetic analysis and ex-situ techniques as well as the density functional theory(DFT) calculations.This work could open a pathway to develop the advanced SDIBs constructed by elemental abundant and environmentally friendly organic materials.

Study on the Synthesis and in vitro Photodynamic Anti-cancer Activity of Tetra(trifluoroethoxy) Germanium Phthalocyanine

The synthesis and in vitro photodynamic anticancer activity of a new photosen- sitizer, tetra（trifluoroethoxy） germanium phthalocyanine （GePcF）, were studied. GePcF was characterized by UV-Vis, IR, MS and elemental analysis. The in vitro photodynamic activity of GePcF was studied by MTT. IC50 of GePcF for SW480 cells of human colonic adenocarcinoma and HeLa cells of cervical cancer were 36.53 and 45.78 μmol/L, respectively. GePcF as a photosensitizer may be used to treat cancers due to its photodyrmmic anticancer activity.

Calculation of Visible Absorption Maxima of Phthalocyanine Compounds by Quantum Theory

Based on HYPERCHEM, the structures of five phthalocyanie compounds were optimized with PM3 and their visible absorption maxima were calculated with ZINDO/S method by selecting appropriate p-p overlap weighting factor (OWFp-p), the agreement with experiment was excellent. The relationship between OWF- and molecular structure parameters was obtained by the method of stepwise regression and was explained in terms of quantum theory. OWF-=0.58126+0.04562ANC1+0.03839X. Where, ANC1 and X are the symbols of average net charges on coordinated bonded nitrogens and electronegativity of central atom, respectively.

Redox chemistry of N_(4-)Fe^(2+)in iron phthalocyanines for oxygen reduction reaction

A precise understanding of the redox chemistry of Nm-Mn+(like N4-Fe^(2+))systems is essential for fundamental studies and rational design of Nm-Mn+-based electrocatalysts for the oxygen reduction reaction(ORR).Herein,three different iron phthalocyanines(FePcs)adsorbed on carbon nanotubes((NH2)4FePc@CNTs,(t-Bu)4FePc@CNTs,and FePc@CNTs)were evaluated to demonstrate the effect of the electron donating power of the substituents on the Fe^(3+)/Fe^(2+)redox potential of FePc@CNTs and the role of these composites as ORR mediators in alkaline media.The Fe^(3+)/Fe^(2+)redox potential of the FePcs was found to shift towards the cathodic region upon substitution with electron-donating groups.This up-field shift in the eg-orbital leads to a lower overlap between the onset potential of the Fe^(3+)/Fe^(2+)redox couple and that of the ORR,and thus,the ORR activity decreased in the following order based on the substitution of FePc:-H>-t-Bu>-NH2.

First-Principles Study of Two Dimensional Transition Metal Phthalocyanine-Based Metal-Organic Frameworks in Kagome Lattice

Transition metal phthalocyanines (TMPc) and relevant derivatives can act as pervasive molecules for their electronic, magnetic, and optical applications. Numerous researches based on TMPc are carried out, attempting to synthesize novel two-dimensional (2D) metal-organic frameworks. Recently, some 2D poly-TMPc frameworks including FePc [J. Am. Chem. Soc. 133, 1203 (2011)], CoPc [Chem. Commun. 51, 2836 (2015)], and Ni-NiPc [J. Mater. Chem. A 6, 1188 (2018)] frameworks have been successfully synthesized experimentally. Meanwhile, potential applications in catalysis, gas storage, and spintronics were predicted by theoretical studies. Here, we propose a new kind of 2D poly-TMPc frameworks with kagome lattice (denoted as kag-TMPc) and systematically investigate their electronic and magnetic properties by employing first-principles calculations. We have demonstrated that the 2D kag-MnPc framework displays quite stable ferromagnetic ordering with Curie temperature about 125 K as indicated by Monte Carlo simulations based on Heisenberg model and prefers out-of-plane easy-magnetization axis. The 2D kag-CrPc framework is an ideal candidate for S=2 kagome antiferromagnet with RT3 magnetic order. Particularly, the investigations on optical absorption suggest that when the TMPc molecules are self-assembled into 2D kag- TMPc frameworks, their absorption wave bands are broadened, especially in visible region.

Synthesis and Photoconductivity of Nanosized Phthalocyanine

Functional phthalocyanine （Pc） compounds of H2Pc, TiOPc, FePc and CIAIPc were synthesized with a yield of 46.7%, 91.2%, 37.4% and 34.0%, respectively. Nanosized TiOPc was synthesized via a one-step sol-gel method and effects of surfactant doses, nucleation temperature on TiOPc particle size and photoconductivity were investigated. When re（PEG）： m（TiOPc） was 0.1 and nucleation temperature was 0℃, the as-obtained TiOPc had the smallest particle size and largest specific surface area, which were 60 nm and 83m^2/g, respectively. TiOPc synthesized under these conditions also exhibits excellent photoconductivity with charging potential V0, dark decay speed Rd and energy for half-discharging of potential E1/2 being 1160 V, 30 V/s and 0.6 1x.s, respectively.

Photogenerated carrier transfer mechanism and photocatalysis properties of TiO_2 sensitized by Zn(Ⅱ) phthalocyanine

The Zn(Ⅱ) phthalocyanine sensitized TiO2(ZnPc-TiO2) nanoparticles were prepared by hydrothermal method via impregnation with ZnPc.The as-prepared photocatalysts were characterized by X-ray diffractometry(XRD) and diffuse reflectance spectroscopy(DRS),and the surface photovoltage spectroscopy(SPS) and photocatalytic degradation of rhodamine B(RhB) were studied under illuminating.The experimental results indicate that TiO2 sensitized by ZnPc extends its absorption band into the visible region effectively,and the sensitized TiO2 has higher activity than TiO2(Degussa P-25) under the simulated solar light and the visible light.Based on the DRS and SPS results,the mechanism about the photogenerated carrier transfer between TiO2 and ZnPc is proposed.At a lower ZnPc content(≤0.20 μmol/g),ZnPc monomer acts as the electron donor,which provides the photoinduced electrons to the conduction band of TiO2.These photoinduced electrons can transfer to molecular oxygen(O2),leading to the formation of active species,such as superoxide/hydroxide radicals and singlet oxygen,which is beneficial to the photocatalytic reaction.While at a higher ZnPc content(>0.20 μmol/g),the formation of ZnPc dimer results in the decrease of photocatalytic activities of ZnPc-TiO2 photocatalyst.

Preparation and Microscopic Characterization of Asphalt Modified by Ethylene Metal-free Phthalocyanine-dispersed Graphene

Graphene-modified asphalt(GMA)for road application was prepared via using metal-free phthalocyanine-dispersed to modify an SK-70#base asphalt with graphene.The preparation parameters are as follows:the content of graphene is 0.26%based on the mass percentage of absolute ethanol,the content of nonmetal phthalocyanine is 190%based on the mass percentage of graphene,and then the GMA is prepared via unique high-speed shearing with continuing to ventilate nitrogen,which can prevent the aging of modified asphalt in the high-speed shearing process,and effectively evaluate the modifier.The penetration,softening point,force ductility,and fracture energy of GMA were significantly improved based on the base asphalt.Thus,the incorporation of graphene could enhance the base asphalt’s high-and low-temperature stability.The modification mechanism was researched via metallographic microscopy,computed tomography(CT),Fourier transform infrared spectroscopy(FTIR),and atomic force microscopy(AFM).Adsorption and physical dispersion of the asphaltenes and resins in the phthalocyanine-graphene system were confirmed.

Targeted Micellar Phthalocyanine for Lymph Node Metastasis Homing and Photothermal Therapy in an Orthotopic Colorectal Tumor Model

Tumor lymph node(LN)metastasis seriously affects the treatment prognosis.Studies have shown that nanoparticles with size of sub-50 nm can directly penetrate into LN metastases after intravenous administration.Here,we speculate through introducing targeting capacity,the nanoparticle accumulation in LN metastases would be further enhanced for improved local treatment such as photothermal therapy.Trastuzumabtargeted micelles(<50 nm)were formulated using a unique surfactantstripping approach that yielded concentrated phthalocyanines with strong near-infrared absorption.Targeted micellar phthalocyanine(T-MP)was an effective photothermal transducer and ablated HT-29 cells in vitro.A HER2-expressing colorectal cancer cell line(HT-29)was used to establish an orthotopic mouse model that developed metastatic disease in mesenteric sentinel LN.T-MP accumulated more in the LN metastases compared to the micelles conjugated with control IgG.Following surgical resection of the primary tumor,minimally invasive photothermal treatment of the metastatic LN with T-MP,but not the control micelles,extended mouse survival.Our findings demonstrate for the first time that targeted small-sized nanoparticles have potential to enable superior paradigms for dealing with LN metastases.

P-functionalized carbon nanotubes promote highly stable electrocatalysts based on Fe-phthalocyanines for oxygen reduction: Experimental and computational studies

Iron(Ⅱ) phthalocyanines(FePc) supported on functionalized nanostructured carbon materials have been studied as electrocatalysts for the oxygen reduction reaction(ORR) in an alkaline medium. Herein, two types of carbon nanotubes(CNTs) have been explored as support, Single-Walled Carbon Nanotubes and Herringbone Carbon Nanotubes(SWCNTs and h CNTs, respectively), both electrochemically modified with ortho-aminophenylphosphonic acid(2APPA), which provides phosphate axial coordinating ligands for the immobilization of FePc molecules. All the catalysts were prepared via a facile incipient wetness impregnation method. Comprehensive experimental analysis together with density functional theory(DFT) calculations has demonstrated both the importance of the five-coordinated Fe macrocycles that favor the interaction between the FePc and the carbon support, as well as the effect of the CNT structure in the ORR. FePc axial coordination provides a better dispersion, leading to higher stability and a favorable electron redistribution that also tunes the ORR performance by lowering the stability of the reaction intermediates. Interestingly, such improvement occurs with a very low content of metal(~1 wt% Fe),which is especially remarkable when h CNT support is employed. This work provides a novel strategy for the development of Fe-containing complexes as precious metal-free catalysts towards the ORR.