Photoelectrochemical performance of a nanostructured BiVO 4 /NiOOH/FeOOH-Cu 2 O/CuO/TiO 2 tandem cell for unassisted solar water splitting

An unassisted solar water splitting tandem cell is fabricated using FeOOH/NiOOH-coated BiVO nanostructures as a photoanode and a TiO -protected heterojunction Cu O/CuO thin film as a photocathode. The individual photoelectrochemical (PEC) performance of the nanostructured BiVO /NiOOH/FeOOH photoanode produces a photocurrent of 2.05 mA cm at 1.23 V RHE, while the Cu O/CuO/TiO photocathode delivers -1.61 mA cm at 0 V RHE under an AM 1.5 filtered illumination of 100 mW cm . The operating point of tandem cell photocurrent is found to be 0.273 mA cm at 0.56 V RHE. From two-electrode linear sweep voltammetry, the tandem cell (BiVO /NiOOH/FeOOH-Cu O/CuO/TiO ) delivers an unassisted current density of 0.201 mA cm at 0 V. The chronoamperometry test further demonstrates the stable nature of the tandem cell, which retains a current density of 0.187 mA cm during a testing duration of 3000 seconds. The proposed tandem cell provides optimized solutions to designing a cost-effective and stable solar water splitting system for the fulfillment of the future energy needs.