Exploring alkaline electrolytes for enhanced hydrogen generation using CuO/TiO2/PPy photocatalyst under diffused light

Abstract

This study investigates the catalytic efficiency of a hybrid CuO/TiO₂/polypyrrole (CTPPy) nanocomposite for the hydrogen evolution reaction (HER) in alkaline media, a critical process in sustainable hydrogen production via the photovoltaic-photoelectrochemical (PV-PEC) method. By leveraging the synergistic integration of CuO, TiO₂, and polypyrrole (PPy), the electrocatalyst achieved a low overpotential of 72.95 mV in 0.1 M NaOH, surpassing performance with other alkali metal cations. The superior HER activity is attributed to the optimal ionic radius of Na⁺, enhancing charge transfer and interaction with catalytic sites. Comprehensive characterization using Fourier Transform Infrared Spectroscopy (FT-IR), Raman Spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM), and Electrochemical Impedance Spectroscopy (EIS) validated the material’s physicochemical properties, including its high surface area and robust charge transport capabilities. PV-PEC tests under 40 W/m² diffused sunlight demonstrated the system’s potential for efficient solar-to-hydrogen conversion under low-light conditions. These findings underscore the potential of CTPPy as a cost-effective, high-performance electrocatalyst for hydrogen generation, offering insights for designing next-generation materials for renewable energy applications.