Engineering CoPcMWCNTs and NiPcMWCNTs nanocomposites for photocatalytic hydrogen production and supercapacitor applications

In this paper, we present a dual application: photocatalytic hydrogen generation and supercapacitor performances of cobalt phthalocyanine multi-walled carbon nanotube (CoPcMWCNTs) and nickel phthalocyanine multi-walled carbon nanotube (NiPcMWCNTs) nanocomposites. Both nanocomposites were synthesized through a solid-surface fusion and ultrasonication approach and characterized using XRD, SEM, EDX and UV–visible spectroscopy techniques. The photocatalytic hydrogen generation via water splitting was performed using a photochemical reactor. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge–discharge (GCD) were employed to assess the supercapacitor performance. Of these nanocomposites, CoPcMWCNTs demonstrated best performance with a higher hydrogen production rate (53.56 mmol g −1 h −1 ), huge energy density (138.48 mWh/cm 2 ), and superior cycling stability (92 %), attributed to its enhanced electrical conductivity, higher TOF values, rapid electron mobility, higher areal capacitance, and improved surface redox activity. These results draw attention to the possible use of CoPcMWCNTs as an efficient photocatalyst for H 2 production as well as a good electrode material for high-performance supercapacitor and offer understanding of how central metal ions influence the electrochemical behaviours of phthalocyanine-based nanocomposites. • CoPcMWCNTs and NiPcMWCNTs offer better photocatalytic hydrogen generation and supercapacitor performance. • Integrating MPcs with fMWCNTs improves hydrogen production efficiency • The central metal in phthalocyanines is critical for hydrogen production and supercapacitor performance. • CoPcMWCNTs demonstrates superior hydrogen generation, energy density and stability.