Photoelectrochemical performance of a nanostructured BiVO4/NiOOH/FeOOH-Cu2O/CuO/TiO2 tandem cell for unassisted solar water splitting

S R Sitaaraman; A Nirmala Grace; Jiefang Zhu; Raja Sellappan

doi:10.1039/d4na00088a

Photoelectrochemical performance of a nanostructured BiVO₄/NiOOH/FeOOH-Cu₂O/CuO/TiO₂ tandem cell for unassisted solar water splitting

Nanoscale Adv. 2024 Mar 19;6(9):2407-2418. doi: 10.1039/d4na00088a. eCollection 2024 Apr 30.

Authors

S R Sitaaraman^{1

2}, A Nirmala Grace¹, Jiefang Zhu³, Raja Sellappan¹

Affiliations

¹ Centre for Nanotechnology Research, Vellore Institute of Technology Vellore India-632014 raja.sellappan@vit.ac.in.
² Department of Electrical and Electronics Engineering, SRM Institute of Science and Technology Ramapuram Chennai India-600089.
³ Department of Chemistry - Ångström Laboratory, Uppsala University 75121 Uppsala Sweden.

Abstract

An unassisted solar water splitting tandem cell is fabricated using FeOOH/NiOOH-coated BiVO₄ nanostructures as a photoanode and a TiO₂-protected heterojunction Cu₂O/CuO thin film as a photocathode. The individual photoelectrochemical (PEC) performance of the nanostructured BiVO₄/NiOOH/FeOOH photoanode produces a photocurrent of 2.05 mA cm^-2 at 1.23 V vs. RHE, while the Cu₂O/CuO/TiO₂ photocathode delivers -1.61 mA cm^-2 at 0 V vs. RHE under an AM 1.5 filtered illumination of 100 mW cm^-2. The operating point of tandem cell photocurrent is found to be 0.273 mA cm^-2 at 0.56 V vs. RHE. From two-electrode linear sweep voltammetry, the tandem cell (BiVO₄/NiOOH/FeOOH-Cu₂O/CuO/TiO₂) delivers an unassisted current density of 0.201 mA cm^-2 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^-2 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.