The fabrication of a thin film CoO-poly(1H-pyrrole)/poly(1H-pyrrole) p-type photocathode with intercalated chloride ions inside the polymer chains for the green hydrogen generation without sacrificing agent

Abstract This study proposes an innovative solution to the challenges associated with hydrogen (H 2 ) gas generation by introducing a novel composite material composed of CoO-Co 2 O 3 -P1HP/P1HP. This composite is synthesized in a single step through the direct reaction of Co(NO 3 ) 2 with pyrrole. The resulting composite exhibits promising morphological characteristics, featuring small particle sizes of approximately 150 nm and notable porosity. This intricate porosity has a great role in facilitating the penetration of photons, enabling effective light absorption throughout the material. Moreover, the composite demonstrates exceptional optical properties, displaying high absorbance across the optical spectrum up to 830 nm, coupled with an optimal bandgap of 1.35 eV. Utilizing this composite as a photocathode in a fabricated three-electrode cell, the study explores the conversion of natural Red Sea water into H 2 gas. The selection of this water as the electrolyte offers several advantages, including its cost-effectiveness, ready availability, and natural self-sacrificing properties. Experimental testing of the photocathode involves subjecting it to various optical conditions, including varying single photon energies and frequencies. Under white light, the photocathode exhibits a promising J ph value of −0.17 mA.cm −2 , surpassing the Jo value of −0.03 mA.cm −2 . This comprehensive evaluation provides insights into the performance of the photocathode under different illumination conditions. Furthermore, the study holds promise for commercial applications, as it presents a pathway for the large-scale conversion of Red Sea water into H 2 gas, with a production rate of 10 μmole h −1 .10 cm 2 . The availability of H 2 gas as a clean and sustainable energy source holds significant potential for addressing energy needs in residential and remote areas, offering a viable alternative to conventional energy sources.