Full‐Solution Processed Halide Perovskite Photoanodes with Carbon/NiFe‐LDH Protection for Efficient Photoelectrochemical Water Oxidation

The development of photoelectrochemical water oxidation (PEC) systems has gained significant relevance in recent years due to the quest for clean fuels, where green hydrogen is one of the main actors in the energy transition. Particularly, there has been a need for precious metal-free electrodes and photoelectrodes that demonstrate high efficiency and stability aiming at having large-scale and low-cost green hydrogen production systems. This work shows advances toward this goal by using nonprecious catalysts and solution-processed materials to achieve efficient, low-cost, and stable photoelectrodes. Specifically, carbon-based hybrid perovskite photoelectrodes coupled with an earth-abundant Nickel-Iron layered double hydroxide (NiFe-LDH) catalyst (carbon/NiFe-LDH) are fabricated and evaluated for oxygen evolution reaction (OER). Devices with an active area of 1.1 cm² exhibit evaluated over 12 h of continuous operation, a 4.57% ABPE at 0.64 V_RHE, and a photocurrent density of 11.71 mA cm^-2 at 1.23 V_RHE. The incorporation of graphite tape results in a system (C/GT/NiFe-LDH) that shows an exceptional operational stability over 125 h and efficiency for this type of photoelectrode with a high photocurrent density of 18.07 mA cm^-2 at 1.23 V_RHE and 8.51% ABPE at 0.67 V_RHE.