This review extensively discusses current developments in bimetallic nanoparticle–GO and bimetallic nanoparticle–MOF nanocomposites as potential catalysts for HER, along with their different synthesis methodologies, structural characteristics, and catalytic mechanisms. The photoelectrocatalytic performance of these catalysts was also compared based on parameters such as Tafel slope, current density, onset potential, turnover frequency, hydrogen yield, activation energy, stability, and durability. The review shows that the commonly used metal alloys in the bimetallic nanoparticle–GO-based catalysts for HERs include Pt-based alloys (e.g., PtNi, PtCo, PtCu, PtAu, PtSn), Pd-based alloys (e.g., PdAu, PdAg, PdPt) or other combinations, such as AuNi, AuRu, etc., while the most used electrolyte sources are H₂SO₄ and KOH. For the bimetallic nanoparticle MOF-based catalysts, Pt-based alloys (e.g., PtNi, PtCu), Pd-based alloys (e.g., PdAg, PdCu, PdCr), and Ni-based alloys (e.g., NiMo, NiTi, NiAg, NiCo) took the lead, with KOH being the most frequently used electrolyte source. Lastly, the review addresses challenges and prospects, highlighting opportunities for further optimization and technological integration of the catalysts as promising alternative photo/electrocatalysts for future hydrogen production and storage.

Cobalt phthalocyanine multiwalled carbon nanotubes (CoPc-MWCNTs), a nanocomposite, are extraordinary electrochemical sensing materials. This material has attracted growing interest owing to its unique physicochemical properties. Notably, the metal at the center of the metal phthalocyanine structure offers an enhanced redox-active behavior used to design solid electrodes for determining varieties of analytes. This review extensively discusses current developments in CoPc-MWCNTs nanocomposites as potential materials for electrochemical sensors, along with their different fabrication methods, modifying electrodes, and the detected analytes. The advantages of CoPc-MWCNTs nanocomposite as sensing material and its future perspectives are carefully reviewed and discussed.

Cobalt phthalocyanine (CoPc)‐based catalysts have garnered significant interest as efficient materials for hydrogen evolution reactions (HER) due to their abundant availability, low cost, tunable electronic structures, and unique light absorption performance. This review offers a thorough examination of the latest developments in CoPc‐based catalysts for HER. It entails a wide range of synthesis approaches, intrinsic characteristics, and catalytic mechanisms associated with these catalysts for HER. We also compare the photo/electrocatalytic performance of these catalysts using parameters like Tafel slope, exchange current density, overpotential, hydrogen yield, turnover frequency, stability, specific surface area, etc. The review shows that the commonly used electrolytes for electrocatalytic HER are KOH, LiClO₄/PBS, and H₂SO₄, while for photocatalytic HER, triethylamine, water, and triethanolamine are frequently used. Among all the electrocatalysts understudied, poly[CoOTPc]‐KB and GO/4N‐CoPc are the best, owing to their lowest overpotentials and Tafel slopes. In terms of photocatalytic hydrogen production, CoPc/TiO₂/Pt has better photocatalytic HER performance compared to its counterparts. This review also highlights the effects of incorporating CoPc with different materials on the photo/electrocatalytic HER performance. Furthermore, the review discusses the challenges and prospects, emphasizing the chances for improving and incorporating CoPc‐based catalysts as a viable option for hydrogen production in the future.

The supercapacitive properties of synthesized nickel phthalocyanine multiwalled carbon nanotubes nanocomposite on a glassy carbon electrode (NiPcMWCNTs-GCE) in four different electrolytes were investigated. The successful synthesis of the NiPcMWCNTs nanocomposite was confirmed by UV/vis electrode spectroscopy, SEM, TEM, EDX, and XRD techniques. The supercapacitive behaviors of the modified electrodes were examined in PBS, H₂SO₄, Na₂SO₄, and SAB electrolytes via CV and EIS techniques. The highest specific capacitance of 6.80 F g⁻¹ was achieved for the GCE-NiPcMWCNTs electrode in 5 mM [Fe(CN)₆]^4−/3− prepared in 0.1 M PBS (pH 7). Charge transfer resistance R_ct values of 0.06, 0.36, 0.61, and 1.98 kΩ were obtained for the GCE-NiPcMWCNTs in H₂SO₄, SAB, Na₂SO₄, and PBS electrolytes, respectively. Power density values, otherwise known as the “knee” frequency f°, of 21.2, 6.87, 2.22, and 1.68 Hz were also obtained for GCE-NiPcMWCNTs in H₂SO₄, Na₂SO₄, PBS, and SAB electrolytes, respectively. GCE-NiPcMWCNTs demonstrated the fastest electron transport capability and the highest power density in H₂SO₄ compared to the other electrolytes. Hence, GCE-NiPcMWCNTs-modified electrodes had high stability, high energy and power densities, and a large specific capacitance.