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.

Quantum Spin Exchange Interactions to Accelerate the Redox Kinetics in Li–S Batteries

Spin-engineering with electrocatalysts have been exploited to suppress the“shuttle effect”in Li–S batteries.Spin selec-tion,spin-dependent electron mobility and spin potentials in activation barriers can be optimized as quantum spin exchange interactions lead-ing to a significant reduction of the electronic repulsions in the orbitals of catalysts.Herein,we anchor the MgPc molecules on fluorinated carbon nanotubes(MgPc@FCNT),which exhibits the single active Mg sites with axial displacement.According to the density functional theory calculations,the electronic spin polarization in MgPc@FCNT not only increases the adsorption energy toward LiPSs intermediates but also facilitates the tunneling process of electron in Li–S batter-ies.As a result,the MgPc@FCNT provides an initial capacity of 6.1 mAh cm^(-2) even when the high sulfur loading is 4.5 mg cm^(-2),and still maintains 5.1 mAh cm^(-2) after 100 cycles.This work provides a new perspective to extend the main group single-atom catalysts enabling high-performance Li–S batteries.

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.

Identification of Dynamic Active Sites Among Cu Species Derived from MOFs@CuPc for Electrocatalytic Nitrate Reduction Reaction to Ammonia

Direct electrochemical nitrate reduction reaction(NITRR)is a promising strategy to alleviate the unbalanced nitrogen cycle while achieving the electrosynthesis of ammonia.However,the restructuration of the high-activity Cu-based electrocatalysts in the NITRR process has hindered the identification of dynamical active sites and in-depth investigation of the catalytic mechanism.Herein,Cu species(single-atom,clusters,and nanoparticles)with tunable loading supported on N-doped TiO_(2)/C are successfully manufactured with MOFs@CuPc precursors via the pre-anchor and post-pyrolysis strategy.Restructuration behavior among Cu species is co-dependent on the Cu loading and reaction potential,as evidenced by the advanced operando X-ray absorption spectroscopy,and there exists an incompletely reversible transformation of the restructured structure to the initial state.Notably,restructured CuN_(4)&Cu_(4) deliver the high NH_(3) yield of 88.2 mmol h^(−1)g_(cata)^(−1) and FE(~94.3%)at−0.75 V,resulting from the optimal adsorption of NO_(3)^(−) as well as the rapid conversion of^(*)NH_(2)OH to^(*)NH_(2) intermediates originated from the modulation of charge distribution and d-band center for Cu site.This work not only uncovers CuN_(4)&Cu_(4) have the promising NITRR but also identifies the dynamic Cu species active sites that play a critical role in the efficient electrocatalytic reduction in nitrate to ammonia.

Conjugated polymerized bimetallic phthalocyanine based electrocatalyst with Fe-N_(4)/Co-N_(4) dual-sites synergistic effect for zinc-air battery

The bifunctional oxygen catalyst is essential for zinc-air batteries(ZABs).Here,an efficient bifunctional oxygen catalyst,PPcFeCo/3D-G,is obtained throughπ-πinteraction between the conjugated polymerized iron-cobalt phthalocyanine(PPcFeCo)with excellent thermal stability and three-dimensional graphene(3D-G).The bimetallic synergistic effect of PPcFeCo,verified by DFT(Density functional theory)calculation,andπ-πinteractions enhances the catalytic activity and durability of the PPcFeCo/3D-G.Regarding electrochemical performance,the PPcFeCo/3D-G with a high electron transfer number(3.98,@0.768 V vs.RHE)has excellent half-wave potential(E_(1/2)=0.890 V vs.RHE)and exhibits outstanding reversibility(ΔE=0.700 V,ΔE=Ej=10-E_(1/2)).The liquid ZAB(LZAB)employed PPcFeCo/3D-G displays a high power density(222 m W cm^(-2)),a specific capacity(792 m A h g-1),and excellent durability(120 h).This work has guiding significance for the preparation of high-efficiency bifunctional catalysts.

Peripheral octamethyl-substituted nickel(Ⅱ)-phthalocyanine-decorated carbon-nanotube electrodes for high-performance all-solid-state flexible symmetric supercapacitors

Construction of advanced electrode materials with unique performance for supercapacitors(SCs)is essential to achieving high implementation in the commercial market.Here,we report a novel peripheral octamethyl-substituted nickel(Ⅱ)phthalocyanine(Ni Me_(2)Pc)-based nanocomposite as the electrode material of all-solid-state SCs.The highly redox-active NiMe_(2)Pc/carboxylated carbon nanotube(CNTCOOH)dendritic nanocomposite provides rapid electron/electrolyte ion-transport pathways and exhibits excellent structural stability,resulting in high-capacity activity and impressive cycling stability.The composite prepared with the optimized weight ratio of Ni Me_(2)Pc:CNT-COOH(6:10)showed the highest specific capacitance of 330.5 F g^(-1)at 0.25 A g^(-1).The constructed NiMe_(2)Pc/CNT-COOH-based all-solid-state symmetric SC device showed excellent performance with a maximum energy density of 22.8 Wh kg^(-1)and outstanding cycling stability(111.6%retained after 35,000 cycles).Moreover,flexible carbon cloth significantly enhanced the energy density of the NiMe_(2)Pc/CNT-COOH all-solid-state symmetric device to 52.1 Wh kg^(-1)with 95.4%capacitance retention after 35,000 cycles,and it could be applied to highperformance flexible electronics applications.These findings provide a novel strategy to design phthalocyanine-based electrode materials for next-generation flexible SC devices.

Sodium-Coordinated Polymeric Phthalocyanines as Stable High-Capacity Organic Anodes for Sodium-Ion Batteries

Sodium-ion batteries(SIBs)have attracted considerable interest as an alternative to lithium-ion batteries owing to their similar electrochemical performance and superior long-term cycle stability.Organic materials are regarded as promising anode materials for constructing SIBs with high capacity and good retention.However,utilization of organic materials is rather limited by their low energy density and poor stability at high current densities.To overcome these limitations,we utilized a novel polymeric disodium phthalocyanines(pNaPc)as SIB anodes to provide stable coordination sites for Na ions as well as to enhance the stability at high current density.By varying the linker type during a one-pot cyclization and polymerization process,two pNaPc anodes with O-(O-pNaPc)and S-linkers(S-pNaPc)were prepared,and their structural and electrochemical properties were investigated.The O-pNaPc binds Na ions with a lower binding energy compared with S-pNaPc,which leads to more facile Na-ion coordination/dissociation when engaged as SIB anode.The use of O-pNaPc significantly improves the redox kinetics and cycle stability and allows the fabrication of a full cell against Na_(3)V_(2)(PO_(4))_(2)F_(3)/C cathode,which demonstrates its practical application with high energy density(288 Wh kg^(-1))and high power density(149 W kg^(-1)).

Cobalt phthalocyanine-based conjugated polymer as efficient and exclusive electrocatalyst for CO_(2) reduction to ethanol

Electrocatalytic conversion of carbon dioxide to high value-added chemicals is a promising method for solving the energy crisis and global warming.Electrochemical active metal-containing conjugated polymers have been widely studied for heterogeneous carbon dioxide reduction.In the present contribution,we designed and synthesized a stable cobalt phthalocyanine-based conjugated polymer,named CoPPc-TFPPy-CP,and also explored its electro-catalytic application in carbon dioxide reduction to liquid products in an aqueous solution.In the catalyst,cobalt phthalocyanine acts as building blocks connected with 1,3,6,8-tetrakis(4-formyl phenyl)pyrenes via imine-linkages,leading to mesoporous formation polymers with the pore size centered at 4.1nm.And the central co-balt atoms shifted to a higher oxidation state after condensation.With these chemical and structural natures,the catalyst displayed a remarkable electrocatalytic CO_(2) reduction performance with an ethanol Faradaic efficiency of 43.25%at-1.0V vs RHE.While at the same time,the electrochemical reduction process catalyzed by cobalt phthalocyanine produced only carbon monoxide and hydrogen.To the best of our knowledge,CoPPc-TFPPy-CP is the first example among organic polymers and metal-organic frameworks that produces ethanol from CO_(2) with a remarkable selectivity.

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%.

食用油中微量颜料的分析鉴定

A pot of cooking oil was contaminated to glaucous.Blue substance had been isolated from the oil,and identified to be phthalocyanine pigment by means of testing physical and chemical properties and analyzing the oxidative degradation products by GC-MS.The Mr of pigment was detected by EI MS to be 575 relating to the copper phthalocyanine.

Isolation and Spectroscopic Characterization of Protonated Mixed [Tetrakis (4-pyridyl)porphyrinato] (phthalocyaninato)Rare Earth (Ⅲ)Double-decker Compounds

The treatment of tetrakis (4-pyridyl) porphyrin H2TPyP with a hydrated rare earth (III) acetylacetonate RE(acac)3 · nH2O (RE=Y, Eu, Gd) in 1,2, 4-trichlorobenzene (TCB) pro- duced a monomeric porphyrinato rare earth compound RE (TPyP) acac, which further reacted with dicyanobenzene in amyl alcohol in the presence of 1, 8-diazabicyclo [5. 4. 0] undec-7-ene (DBU), giving HRE(TPyP) (Pc) in a good yield. Upon exposure to air, part of the protonated mixed double-deckers in CHC13 solutions converted slowly to the corresponding neutral complexes RE (TPyP) (Pc). These protonated complexes were characterized by means of UV-V is, IR, NMR, mass spectroscopies. The quaternarization of these protonated mixed double-deckers with methyl iodide produced the salts of tetramethylated cations [HRE(TMPyP) (Pc)]4+.

Highly electroactive N–Fe hydrothermal carbons and carbon nanotubes for the oxygen reduction reaction

Glucose-derived carbons were prepared by hydrothermal carbonization of glucose followed by carbonization or activation to obtain carbon materials with different microporosities. These microporous carbons and carbon nanotubes(CNTs) were functionalized with melamine and/or iron(Ⅱ) phthalocyanine(FePc)following three different methodologies:(i) Functionalization with melamine via thermal treatment,(ii)incorporation of the lowest amount of FePc reported in the literature via incipient wetness impregnation followed by thermal treatment and(iii) functionalization with melamine followed by Fe Pc incorporation.The chemical and textural characterization of the prepared materials and their electrochemical assessment allowed to understand the role of microporosity in the incorporation of FePc and its effect on the oxygen reduction reaction(ORR). It was observed that FePc was preferentially incorporated inside the porous structure, especially in samples with more developed microporosity. However, functionalization with melamine modified the textural properties and the surface chemistry, favoring the incorporation of FePc on the surface. Regarding the electrochemical performance, the presence of FePc greatly enhanced the electroactivity of the microporous catalysts. An onset potential of 0.88 V and a four-electron pathway were obtained for glucose-derived carbons, whereas the limiting current densities and kinetic current densities rose by 126% and 222%, respectively, in comparison to the base sample. Notwithstanding, the highest electrochemical activity was observed for the sample prepared with CNTs, due to the synergy between the active metal centers and their highly graphitic carbon structure. The electrochemical parameters of CNTFeP csurpass the commercial Pt/C. The half-wave potential is 40 mV higher, the limiting current density increases by 17%, and a negligible production of by-products(< 1%) was observed.

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.

Targeting Hypoxic Tumors with Hybrid Nanobullets for Oxygen-Independent Synergistic Photothermal and Thermodynamic Therapy

Hypoxia is a feature of solid tumors and it hinders the therapeutic efficacy of oxygen-dependent cancer treatment.Herein,we have developed all-organic oxygen-independent hybrid nanobullets ZPA@HA-ACVA-AZ for the“precise strike”of hypoxic tumors through the dual-targeting effects from surface-modified hyaluronic acid(HA)and hypoxia-dependent factor carbonic anhydrase IX(CA IX)-inhibitor acetazolamide(AZ).The core of nanobullets is the special zinc(II)phthalocyanine aggregates(ZPA)which could heat the tumor tissues upon 808-nm laser irradiation for photothermal therapy(PTT),along with the alkyl chain-functionalized thermally decomposable radical initiator ACVA-HDA on the side chain of HA for providing oxygen-independent alkyl radicals for ablating hypoxic cancer cells by thermodynamic therapy(TDT).The results provide important evidence that the combination of reverse hypoxia hallmarks CA IX as targets for inhibition by AZ and synergistic PTT/TDT possess incomparable therapeutic advantages over traditional(reactive oxygen species(ROS)-mediated)cancer treatment for suppressing the growth of both hypoxic tumors and their metastasis.

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.

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.