Stable hydrogen generation from Ni- and Co-based co-catalysts in supported CdS PEC cell

To improve the limited efficiency and stability of CdS photoanodes in a photoelectrochemical (PEC) cell, the nanostructured CdS photoanode was modified with Ni(OH)(2), NiO, Co(OH)(2), and Co3O4 water-oxidation-nano co-catalysts (WOC). Co(OH)(2) nanorice and Ni(OH)(2) nanosheet co-catalysts were obtained by a simple chemical precipitation method. Modification by the co-catalysts gives longer stability (>8 h) to CdS electrodes, and facilitates impulsive H-2 evolution in PEC cells. Nano-NiO modification yields a two-fold increase in photocurrent density and the highest H-2 evolution of 2.5 mmol h(-1). A dual role for Ni related co-catalysts over CdS surface, that is forming a p-n junction and acting as an effective co-catalyst, improves the photocurrent and hydrogen evolution rate, respectively. Improvement in stability was measured using X-ray photoelectron spectroscopy and prolong chronoamperometry measurements. The present report focuses on exploration of chemically synthesized earth-abundant and cost-effective co-catalysts for PEC H-2 generation.