Nickel Phthalocyanine Research Articles

Synthesis, Characterization, and Antioxidant Potential of Nickel (II) Phthalocyanine for Industrial and Biomedical Applications

Background: Nickel (II) phthalocyanine (Ni-Pc) is a prominent metallophthalocyanine compound known for its unique optical, electronic, and antioxidant properties. Its ability to form stable complexes with metal ions has made it a subject of interest in industrial and biomedical applications, including advanced material development and therapeutic interventions. Methods: Ni-Pc was synthesized using commercially obtained chemicals without additional purification. Its structural and physicochemical properties were analyzed through Fourier Transform Infrared (FTIR) spectroscopy, UV-Visible spectroscopy, and proton nuclear magnetic resonance (¹H NMR) spectroscopy. The antioxidant potential of Ni-Pc was evaluated via the DPPH radical scavenging assay, comparing its activity to ascorbic acid. Results: The synthesized Ni-Pc exhibited a melting point of 355°C with a yield of 75%. Elemental analysis confirmed its purity and composition (C: 66.17%, H: 19.88%, N: 20.01%). FTIR data revealed characteristic O–H, C=C, C=N, C–N, and Ni–N stretching vibrations, confirming its molecular structure. UV-Visible spectroscopy displayed prominent absorption bands, including a Q-band at ~670 nm, indicative of its intact aromatic macrocyclic system. ¹H NMR analysis confirmed the successful synthesis of Ni-Pc through characteristic aromatic CH group signals at 7.5–8.04 ppm. The DPPH assay demonstrated its antioxidant efficacy, with an 85% scavenging activity at 25 μg, comparable to ascorbic acid. Conclusion: Ni-Pc was successfully synthesized and characterized, exhibiting significant antioxidant potential alongside versatile structural properties. Its robust ability to coordinate with various metal ions underscores its importance in industrial applications, such as carbon nanotube development, and biomedical fields, including antitumor and antibacterial therapies. These findings highlight Ni-Pc’s potential as a multifunctional compound for advanced material science and therapeutic advancements.

Recent progress on nickel phthalocyanine-based electrocatalysts for CO2 reduction.

The electrocatalytic reduction of CO2 to high-value fuels by renewable electricity is a sustainable strategy, which can substitute for fossil fuels and circumvent climate changes induced by elevated CO2 emission levels, making the rational design of versatile electrocatalysts highly desirable. Among all the electrocatalytic materials used in the CO2 reduction reaction, nickel phthalocyanine (NiPc)-based electrocatalysts have attracted considerable attention recently because of their high CO selectivity and catalytic activity. Herein, we review the latest advances in CO2 electroreduction to CO catalyzed by immobilized NiPc and its derivatives on diverse surfaces. Specific strategies, the structure-performance relationship and the CO2-to-CO reaction mechanism of these NiPc-based electrocatalysts are analyzed. Future opportunities and challenges for this series of powerful heterogeneous electrocatalysts are also highlighted.

Concurrent activation of CO2 and H2O on sulfur-doped CNT-supported nickel phthalocyanine for electrochemical CO2 reduction to CO.

Concurrent activation of CO2 and H2O is essential for CO2 electroreduction reaction, but challenging. A sulfur-doped carbon nanotubes-supported nickel phthalocyanine (NiPc/S-CNTs) can concurrently activate CO2 and H2O, promoting CO2 protonation to *COOH. The NiPc/S-CNTs achieves CO Faraday efficiency of >96% at current density from -20 to -140 mA cm-2.

Novel nickel(II) phthalocyanine/reduced graphene oxide: an electrochemical sensing platform for analysis of hydroquinone and chloramphenicol in environmental samples.

Novel tetra-2-(biphenyl-4-yl)-1,3-benzoxazol-carboxamide nickel(II) phthalocyanine (NiTBPBXCAPc) and rGO were confirmed using FT-IR, UV-vis, XRD, TGA and Raman spectra. The NiTBPBXCAPc and rGO nanocomposite has been developed to detect hydroquinone (HQN) and chloramphenicol (CPC). NiTBPBXCAPc has been examined using cyclic voltammetry (CV), linear sweep voltammetry (LSV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) analysis. The simultaneous CV analysis of HQN and CPC demonstrated the ability of NiTBPBXCAPc@rGO/GCE to execute simultaneous redox reactions. The voltammetric and amperometric limit of detection for HQN and CPC was determined to be 4.5 and 3.5 nM respectively, with a sensitivity of 0.446 and 0.416 μA M-1 cm-2. The amperometric LOD was observed to be 5 and 4 nM with a sensitivity of 0.235 and 0.288 μA M-1 cm-2. Additionally, the NiTBPBXCAPc@rGO/GC electrode is also used for real sample analysis with outstanding recovery. The long-term storage stability, reusability, and real-world sample analysis of the NiTBPBXCAPc@rGO/GC electrode demonstrated its use in environmental analysis.

Polyvalent interaction and confinement to suppress polysulfide dissolution and improve electrocatalysis

Sulfide and lithium ions of polysulfides interact with nickel cations and pyrrolic nitrogens of nickel phthalocyanine cross-linked polypyrrole, respectively, suppressing the polysulfide shuttle effect while electrocatalysing the polysulfide conversion.

Graphite conjugated nickel phthalocyanine for efficient CO2 electroreduction and Zn-CO2 batteries.

The linking chemistry between molecular catalysts and substrates is a crucial challenge for enhancing electrocatalytic performance. Herein, we elucidate the influence of various immobilization methods of amino-substituted Ni phthalocyanine catalysts on their electrocatalytic CO2 reduction reaction (eCO2RR) activity. A graphite-conjugated Ni phthalocyanine, Ni(NH2)8Pc-GC, demonstrates remarkable electrocatalytic performance both in H-type and flow cells. In situ infrared spectroscopy and theoretical calculations reveal that the graphite conjugation, through strong electronic coupling, increases the electron density of the active site, reduces the adsorption energy barrier of *COOH, and enhances the catalytic performance. As the cathode catalyst, Ni(NH2)8Pc-GC also displays remarkable charge-discharge cycle stability of over 50 hours in a Zn-CO2 battery. These findings underscore the significance of immobilization methods and highlight the potential for further advancements in eCO2RR.

A reductively convertible nickel phthalocyanine precursor as a biological thiol-responsive turn-on photoacoustic contrast agent.

A nickel phthalocyanine precursor bearing poly(ethylene glycol) as a turn-on contrast agent for photoacoustic imaging was prepared. The water-soluble polymeric chains were smoothly eliminated through thiol-mediated reductive aromatization in cancer cells, enabling the detection of endogenous biological thiols in vitro and in vivo.

Novel nitrogen‐rich anchored nickel (II) phthalocyanine with composite of multiwalled carbon nanotubes on modified glassy carbon electrode: Sensitive and selective electrocatalytic activity of nitrite

This work describes the synthesis of novel nickel tetra substituted 6‐bromobenzothiazole carboxamide nickel (II) phthalocyanine (NiTBBTCAPc) and confirmed by spectroscopic‐microscopic methods and as well as electrochemical analysis. The electrochemical oxidation of nitrite was studied on NiTBBTCAPc‐multiwalled carbon nanotube (MWCNTs)/glassy carbon electrode (GCE) due to its better electron transferring ability than bare GCE and NiTBBTCAPc/GCE. As there is acceleration in surface area of GCE by multiwalled carbon nanotubes, a cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometric techniques utilized for nitrite sensor were developed. The sensor exhibited a fast response towards nitrite with a detection limit of 3.012 nM and a linear concentration range of 50–900 nM by the CV method. The fabricated sensor shows excellent electrocatalytic activity compared with the modified electrode with Pc with a composite of MWCNTs towards oxidation of nitrite. The NiTBBTCAPc‐MWCNTs/GCE shows good repeatability, stability, and high selectivity even in the presence of excess ascorbic acid (AA), dopamine (DA), uric acid (UA), paracetamol (PA), glucose, Pb (II), Cd (II), Ca (II), and Mg (II). Finally, for usage in practical applications, the modified electrode was employed to achieve quantitative detection of nitrite in drinking water and cabbage vegetable samples, respectively.

Synthesis and Characterization of Metal Phthalocyanine Complex Using Substituted 4-Nitrophthalonitrile Ligand

In this research work, four compounds: 4-nitrophthalamide, 4-nitrophthalonitrile and 4-(ciproxy) phthalonitrile and phthalocyanine complex were synthesized. The synthesis began with the nitration in the position 4 of phthalamide which led to the formation of 4-nitrophthalamide. Dehydration by the thionyl chloride in N,N-dimethylformamide (DMF) led to the formation of 4-nitrophthalonitrile and further reaction of ciprofloxacin with 4-nitrophthalonitrile in DMF forms the phthalonitrile derivative, cyclotetramerization of 4-(ciproxy) phthalonitrile in the presence of nickel salt gave substituted metal phthalocyanine complex. The structures of the synthesized compounds were characterized by NMR, FT-IR spectrophotometry and UV-VIS. Melting point of the compounds ware checked by Griffin MFB-590. The melting points of 4-nitrophthalamide and 4-nitrophthalonitrile were found to be 223 oC and 175 oC respectively. Solubility of the compounds was confirmed in some common laboratory solvent (acetone, methanol and DMF). The electronic spectra of nickel phthalocyanine compound in DMF showed intense Q absorption at 690 nm. The thermal stability of the phthalocyanine derivatives was checked by TGA; the phthalocyanine was heated up to 700 oC to determine the degradation temperature. The temperatures at which the phthalocyanine began to exhibit weight loss was 309 oC. It could, therefore, be concluded that the metal phthalocyanines prepared in this study showed suitably high thermal stability and can be used for further analysis.

Conjugated Nickel Phthalocyanine Derivatives for Heterogeneous Electrocatalytic H2 O2 Synthesis.

Electrocatalytic hydrogen peroxide (H2 O2 ) production has emerged as a promising alternative to the chemical method currently used in industry, due to its environmentally friendly conditions and potential for higher activity and selectivity. Heterogeneous molecular catalysts are promising in this regard, as their active site configurations can be judiciously designed, modified, and tailored with diverse functional groups, thereby tuning the activity and selectivity of the active sites. In this work, nickel phthalocyanine derivatives with various conjugation degrees are synthesized and identified as effective pH-universal electrocatalysts for H2 O2 production after heterogenized on nitrogen-decorated carbon, with increased conjugation degrees leading to boosted selectivity. This is explained by the regulated d-band center, which optimized the binding energy of the reaction intermediate, reducing the energy barrier for oxygen reduction and leading to optimized H2 O2 selectivity. The best catalyst, NiPyCN/CN, exhibits a high H2 O2 electrosynthesis activity with ≈95% of H2 O2 faradic efficiency in an alkaline medium, demonstrating its potential for H2 O2 production.

Use of highly sensitive nickel phthalocyanine based humidity sensor to explore the imprecise data analysis for robot body

PurposeThe purpose of this study is to fabricate a highly sensitive humidity sensor for observing the humidity effect on a robot’s body as an application of the Internet of Things. The sensor has been fabricated by depositing a thin sensing layer of nickel phthalocyanine (NiPc) between two silver electrodes.Design/methodology/approachThe structure of the thin film was observed by X-ray diffraction, optical properties by UV Vis and surface morphology by scanning electron microscope. The capacitance and the resistance with respect to change in relative humidity from 0 to 100%RH have been measured by LCR meter at 1 kHz.FindingsThe sensor’s response time is 7.5 s and its recovery time is 3.7 s, with high sensitivity of 127,259 pF/%RH and 332.287 MΩ/%RH. The authors have also used a proposed sensor on a steel body and observed humidity values. The analysis of all measured values was performed through the classical and neutrosophic approaches. By comparing, the authors have observed that the neutrosophic approach is more efficient in analyzing the sensor data.Originality/valueIn this work, the authors will fabricate a capacitive and resistive-type humidity sensor using the thin film of NiPc. The structural, optical and morphological properties of NiPc thin film will be investigated with different characterization techniques. The electric properties, i.e. capacitance and resistance, will be measured at intervals with an LCR meter by changing relative humidity (%RH). Moreover, the measured data will be analyzed through different statistical approaches, as already used in [12].

Nanocomposite of nickel phthalocyanine nanoparticles and detonation nanodiamonds for enhanced electrocatalysis

This work reports on nickel phthalocyanines nanoparticles (NPs)-detonation nanodiamonds (DNDs) as potential platforms for electrocatalytic detection of nitrite in 0.2 M sodium hydroxide solution. The electrode surfaces were analysed using cyclic voltammetry and electrochemical impedance which showed enhanced electron transfer after modification, with (1)-NPs-DNDs showing relatively better electron tranter ability. The electrocatalytic performance of modified surfaces was investigated towards nitrite electrooxidation. The results demonstrated that tetrakis [4-(4-(4,5-dichloro-1H-benzo[d]imidazole-2-yl) phenoxy] phthalocyanato nickel (II) (1)-NPs-DNDs gave more negative oxidation potential (0.87 V), highest background corrected current (120.3 μA), highest electrocatalytic rate constant (2.84 × 104 M−1 s−1) and lowest limit of detection of (0.098 nM). These factors rendered (1)-NPs-DNDs electrode surface better than others studied here making it a promising sensor for nitrite.

Modulating the Density of Catalytic Sites in Multiple-Component Covalent Organic Frameworks for Electrocatalytic Carbon Dioxide Reduction.

It is generally assumed that the more metal atoms in covalent organic frameworks (COFs) contribute to higher activity toward electrocatalytic carbon dioxide reduction (CO2RR) and hindered us in exploring the correlation between the density of catalytic sites and catalytic performances. Herein, we have constructed quantitative density of catalytic sites in multiple COFs for CO2RR, in which the contents of phthalocyanine (H2Pc) and nickel phthalocyanine (NiPc) units were preciously controlled. With a molar ratio of 1/1 for the H2Pc and NiPc units in COFs, the catalyst achieved the highest selectivity with a carbon monoxide Faradaic efficiency (FECO) of 95.37% and activity with a turnover frequency (TOF) of 4713.53 h-1. In the multiple H2Pc/NiPc-COFs, the electron-donating features of the H2Pc units provide electron transport to the NiPc centers and thus improved the binding ability of CO2 and intermediates on the NiPc units. The theoretical calculation further confirmed that the H2Pc units donated their electrons to the NiPc units in the frameworks, enhanced the electron density of the Ni sites, and improved the binding ability with Lewis acidic CO2 molecules, thereby boosting the CO2RR performance. This study provides us with new insight into the design of highly active catalysts in electrocatalytic systems.

The Study of Interaction Activity of Nickel (ll) Phthalocyanine Complex Bearing Tetra Substituted Phenoxy-3-Methoxybenzoic Acid Groups with DNA

Nickel phthalocyanine complex containing 3-methoxybenzoic acid groups was acquired and specified by way of Fourier Transform Infrared, NMR and UV-Visble spectroscopy procedures. Interaction of PcNi with the DNA molecule was examined via electronic absorption spectra, fluorescence spectra, melting point, viscosity, and the electrophoresis technics, respectively. The interaction activity of PcNi against the DNA was examined by way of absorption spectra titrations and the fluorescence spectra, farther by conducting melting point, viscosity procedures in the buffer of a pH 7.02. The obtained outcomes from these methods demonstrated that PcNi indicated substantial binding affinity to the DNA via intercalating by Kb of 1.31 x 106 m-1. Further, the interacting activity of PcNi on the DNA was analyzed by which electrophoresis technique and this procedure indicated that PcNi complex exhibits strong binding affinity on the DNA.

Carbon‐Dot‐Mediated Highly Efficient Visible‐Driven Photocatalytic Hydrogen Evolution Coupled with Organic Oxidation

AbstractPhotocatalytic hydrogen evolution coupled with organic oxidation reaction is a promising alternative to water splitting, where the efficiency is limited due to the weak correlation between charge separation and surface redox reactions. Here, employing nickel phthalocyanine (NiPc) for hole extraction, NiPc‐modified carbon dots (CDs) are combined with Cu–In–Zn–S quantum dots (CIZS QDs) toward a profound understanding of electron/hole extraction and surface proton generation and reduction. The optimal hydrogen evolution rate reaches 4.10 mmol g−1 h−1 for CIZS/NiPc–CDs with l‐ascorbic acid for hole consumption, 8.10 times to that of CIZS QDs, which is further promoted to 11.12 mmol g−1 h−1 under electron/hole coextraction with Ni2+ introduction. For benzyl‐alcohol‐oxidation‐coupled H2 evolution, this strategy shows a more dramatic activity enhancement (19.54 times), which is also appliable to methanol‐ or furfuryl‐alcohol‐oxidation coupling systems with state‐of‐the‐art activities. Transient photovoltage spectroscopy and apparent kinetics analysis indicate, for the first time, a light‐induced electrocatalysis effect consistent with the Volmer–Heyrovsky process, which establishes a quasiquantitative basis for balancing charge extraction and surface reactions.

Construction of Amphiphilic Indocyanine–Green–Based Langmuir Film and Drop–Casting Film with Photoelectric Conversion Properties

Molecular self–assembly is the automatic formation of functional assemblies of different structural components through weak, reversible, non–covalent interactions on the basis of molecular recognition. Amphiphilic molecules have a natural advantage in self–assembly at the gas/liquid interface. In this work, two amphiphilic molecules with a special molecular structure, indocyanine green (ICG) and a derivative of indocyanine green (CCS), were combined with two dye molecules (tetraphenylporphyrin tetrasulfonic acid hydrate (TPPS) and nickel (II) phthalocyanine–tetrasulfonic acid tetrasodium salt (TsNiPc) for self–assembly through the Langmuir–Blodgett (LB) technique. The nanostructure and assembly behavior in ordered self–assembled films are effectively regulated by inducing dye molecules to form different types of aggregates (H– and J–aggregates). In addition, we prepared composite films containing the same functional components using the conventional drop–casting technique and performed a series of comparative experiments with LB films. The degree of hydrophilicity was found to be related to roughness, with LB composite films being flatter and denser, with the lowest roughness and the best hydrophobicity compared to drop–casting films. Notably, the LB films showed better optoelectronic properties under the same conditions, providing new clues for the application of optoelectronic functional ultrathin film devices.

Enhancing Stability and Efficiency of Perovskite Solar Cells with a Bilayer Hole Transporting Layer of Nickel Phthalocyanine and Poly(3‐Hexylthiophene)

AbstractTo expedite the commercialization of perovskite solar cells (PSCs), researchers are exploring the feasibility of employing nickel phthalocyanine (NiPc) as a hole transport material (HTM) due to its cost‐effectiveness, excellent thermal stability, and suitability for solution coating. However, the low LUMO energy level of the NiPc may limit its ability to block photoelectrons generated in the perovskite layer from recombining with holes, which can reduce the overall efficiency of the solar cell. One solution is to use cascaded bilayers with HTMs that have relatively higher LUMO levels. In this study, a bilayer consisting of NiPc and poly(3‐hexylthiophene) (P3HT) is employed as the HTM, where the P3HT exhibits vertical phase separation during the coating process. By optimizing the mixing amount of P3HT into the NiPc, a record power conversion efficiency of 23.11%, the highest reported for NiPc‐based PSCs is achieved. Moreover, an excellent long‐term stability is demonstrated by encapsulating the PSC in polyisobutylene, with the device retaining 90% of its initial efficiency after exposure to 85 °C and 85% relative humidity for 1000 h.

Impedance and voltammetry detection of bromate in food samples using NiPcMWCNTs modified glassy carbon electrode

A sensitive bromate sensor was developed using nickel phthalocyanine multi-walled carbon nanotubes nanocomposite modified on a glassy carbon electrode. The NiPcMWCNTs nanocomposite was prepared from nickel nanoparticles, phthalocyanine, and functionalized MWCNTs via ultrasonication. UV–visible spectroscopy, SEM, XRD, TEM, and EDX techniques were used to verify the successful fabrication of the nanomaterials. The results of the EIS and CV experiments conducted in 5 mM K3(Fe(CN)6/K4(Fe(CN)6 made in 0.1 M of PBS (pH 7) revealed that the NiPcMWCNTs/GCE exhibited higher current response, faster electron transfer, and high specific capacitance compared to other electrodes. The electrochemical reduction of bromate was actualized in 0.1 M H2SO4 (pH 1) using EIS and SWV techniques. Using the EIS technique, an LoD of 6.72 μM was obtained with a sensitivity of 483.7 μA μM−1 over a linear dynamic range (LDR) of 24–100 μM. Whereas, with the SWV technique, a lower LoD (1.47 μM) was obtained with a higher sensitivity (1293 μA μM−1) over an LDR of 12–56 μM. The developed sensor was characterized by good selectivity, high stability (95.5%), and good reproducibility (% RSD; 3.5%). The fabricated sensor was effectively used to detect bromate in bread samples with a good recovery rate, demonstrating the practical application of the sensor to detect bromate in real samples (bread).

Photoresponse and noise characteristics of in-situ fabricated NiPc nanowire photodetectors

The interface between organic nanowires and metal layers plays a key role in determining the photoresponse and noise characteristics of organic nanowires. Herein, nickel phthalocyanine (NiPc) nanowires are self-aligned along parallel nanogrooves on a sapphire surface, and then photodetectors are fabricated in situ without post-growth transfer and alignment steps. This in-situ fabrication eliminates unpredictable factors associated with post-growth processing steps and allows us to focus on studying the influence of different nanowire-metal interfaces. Two different electrodes prepared by thermal evaporation deposition (TED) and etching-assisted transfer printing (ETP) are compared. While both electrodes ensure that NiPc nanowires exhibit a sensitive photoresponse in the 380–800 nm spectrum, the ETP electrodes result in higher sensitivity but an order of magnitude slower response due to the increased nanowire-metal interfacial capacitance. The noise power spectral density (PSD) confirms that for both photodetectors, the frequency-dependent 1/f noise dominates at frequencies below 10 kHz while the frequency-independent white noise increases significantly at higher frequencies. However, while the noise PSD of the photodetectors with TED electrodes remains stable with increasing temperature and bias, the noise PSD of the photodetectors with ETP electrodes increase by four to twelve orders of magnitude due to significantly increased electromigration and structural damage.

Dispersed Nickel Phthalocyanine Molecules on Carbon Nanotubes as Cathode Catalysts for Li-CO2 Batteries.

The Li-CO2 battery has great potential for both CO2 utilization and energy storage, but its practical application is limited by low energy efficiency and short cycle life. Efficient cathode catalysts are needed to address this issue. Herein, this work reports on molecularly dispersed electrocatalysts (MDEs) of nickel phthalocyanine (NiPc) anchored on carbon nanotubes (CNTs) as the cathode catalyst for Li-CO2 batteries. The dispersed NiPc molecules efficiently catalyze CO2 reduction, while the conductive and porous CNTs networks facilitate CO2 evolution reaction, leading to enhanced discharging and charging performance compared to the NiPc and CNTs mixture. Octa-cyano substitution on NiPc (NiPc-CN) further enhances the interaction between the molecule and CNTs, resulting in better cycling stability. The Li-CO2 battery with the NiPc-CN MDE cathode shows a high discharge voltage of 2.72V and a small discharging-charging potential gap of 1.4V, and can work stably for over 120 cycles. The reversibility of the cathode is confirmed by experimental characterizations. This work lays a foundation for the development of molecular catalysts for Li-CO2 battery cathodes.