Process Accumulated 8% Efficient Cu₂ZnSnS₄‐BiVO₄ Tandem Cell for Solar Hydrogen Evolution with the Dynamic Balance of Solar Energy Storage and Conversion

Abstract

A process accumulated record solar to hydrogen (STH) conversion efficiency of 8% is achieved on the Cu 2 ZnSnS 4 -BiVO 4 tandem cell by the synergistic coupling effect of solar thermal and photoelectrochemical (PEC) water splitting with the dynamic balance of solar energy storage and conversion of the greenhouse system. This is the first report of a Cu 2 ZnSnS 4 -BiVO 4 tandem cell with a high unbiased STH efficiency of over 8% for solar water splitting due to the greenhouse device system. The greenhouse acts as a solar thermal energy storage cell, which absorbs infrared solar light and storage as thermal energy with the solar light illumination time, while thermoelectric device (TD) converts thermal energy into electric power, electric power is also recycled and added onto Cu 2 ZnSnS 4 -BiVO 4 tandem cell for enhanced overall water splitting. Finally, the solar water splitting properties of the TD-Cu 2 ZnSnS 4 -BiVO 4 integrated tandem cell in pure natural seawater are demonstrated, and a champion STH efficiency of 2.46% is presented, while a large area (25 cm 2 ) TD-Cu 2 ZnSnS 4 -BiVO 4 integrated tandem device with superior long-term stability is investigated for 1 week, which provides new insight into photoelectrochemical solar water splitting devices.

Dual Shield: Bifurcated Coating Analysis of Multilayered WO3/BiVO4/TiO2/NiOOH Photoanodes for Sustainable Solar-to-Hydrogen Generation from Challenging Waters

“…This rate can be further elevated to 70–80 μmol/h cm 2 by introducing passivation layers or cocatalysts coatings. Moreover, the adoption of a tandem cell configuration serves to amplify the PCD, consequently enhancing the overall rate of hydrogen evolution …”

“…Moreover, the adoption of a tandem cell configuration serves to amplify the PCD, consequently enhancing the overall rate of hydrogen evolution. 92 To assess the stability of the photoanode in PEC hydrogen generation reactions, we conducted a series of PEC experiments spanning four cycles. The hydrogen generation rate was We verify the recovering Zn 2+ metal ions through electrochemical deposition onto the cathode surface (Pt mesh) using SEM images, as depicted in Figure 9a−d.…”

Comparing the net-energy balance of standalone photovoltaic-coupled electrolysis and photoelectrochemical hydrogen production

“…This value is also justified by the demonstration of PEC devices at lab scale with ∼8% conversion efficiency. 90,91…”

“…This value is also justified by the demonstration of PEC devices at lab scale with B8% conversion efficiency. 90,91 Most studies of experimental PEC devices in the literature only show or test for PEC photoelectrode stability over 1 day or less, 92,93 after which time there is already significant degradation. One demonstration of a photoelectrochemical cell was a 50 cm 2 hematite photoanode in tandem with two silicon heterojunction solar cells that reported a very stable performance of 0.04% annualised degradation over 42 days.…”

Strain‐Induced Distortions Modulate the Optoelectronic Properties of Epitaxial BiVO4 Films

“…[3,4] Various bulk chemical modifications (e.g., doping) and nanostructuring strategies have been implemented in state-of-the-art BiVO 4 photoanodes to enhance its optoelectronic and photoelectrochemical properties, thus driving its water oxidation photocurrents to near-theoretical maximum levels (7.5 mA•cm −2 , assuming all AM1.5 photons with energy larger than the bandgap E g ≈ 2.4-2.5 eV of BiVO 4 are collected). [5][6][7][8] Despite the progress mentioned above, one particular aspect that is still poorly understood, especially in the case of BiVO 4 , is the impact of epitaxial strain modulation on its optoelectronic properties. When exploited, this strategy has the potential to tailor and optimize the photoabsorber's interaction with light.…”