Experimental performance assessment of efficient photoelectrodes for solar hydrogen production

This work examines the photoelectrochemical (PEC) performance of Ni-doped Cu 2 O photocathodes fabricated on a stainless steel (SS316) substrate via spin coating. The specific characterisation studies conducted using XRD, FE-SEM, Mott-Schottky, and electrochemical characterisation techniques demonstrate that Ni doping alters the electronic structure of Cu 2 O, enhancing charge-carrier separation and reducing recombination losses. Regarding photocurrent density, pure Cu 2 O generates roughly 50 μA cm -2 , whereas electrodes doped with 5–10% Ni achieve values between 250–350 μA cm -2 . The maximum hydrogen production rate recorded was 1665 μmol·g -1 ·h -1 for 10% Ni-doped Cu 2 O, representing an estimated two-fold enhancement relative to pure Cu 2 O. The assessment of film thickness revealed that the four-layer electrodes exhibited excellent performance, achieving hydrogen generation of 1469 μmol·g -1 . The energy and exergy efficiencies rose from roughly 1.5% for pure Cu 2 O to over 2.5% with the incorporation of 10% Ni. The findings indicate that a combination of Ni and optimal film thickness markedly enhances the effectiveness of Cu 2 O photocathodes for PEC hydrogen production.