Promoting Photoelectrochemical Activity and Stability of WO₃/BiVO₄ Heterojunctions by Coating a Tannin Nickel Iron Complex

Abstract

Achieving enhanced photoelectrochemical (PEC) activity and stability of a photoanode remains as a formidable challenge. In this study, a porous tannin nickel iron complex coated WO3/BiVO4 heterojunction (WO3/BiVO4@TANiFe) is constructed to achieve enhanced PEC activity and stability. The in situ construction of a type-II heterostructure is highly beneficial for broad visible light utilization and efficient separation of photogenerated carriers. In addition, the intact coating of ultrathin tannin nickel iron nanolayer could not only accelerate the reaction kinetics of water oxidation but also safeguard the semiconductors from photocorrosion during the PEC reaction. As a result, the as-designed WO3/BiVO4@TANiFe ternary photoelectrode exhibits an outstanding photocurrent density of 3.7 mA cm–2 at 1.23 V vs RHE with substantially enhanced running durability at high photocurrent density. The present study would provide a rational route for developing highly active and stable photoanodes for solar-energy conversion applications.

Plasma-Wind-Assisted In2S3 Preparation with an Amorphous Surface Structure for Enhanced Photocatalytic Hydrogen Production

“…The charge separation efficiency ( η sep ) of the sample is calculated based on the equation where J sulfite is the photocurrent density with the addition of Na 2 SO 3 in the electrolyte solution, J abs is the photocurrent density when the adsorbed photons completely convert to currents. The calculated process is presented in supporting information [ 36 , 37 ]. The photocurrent densities J sulfite of the In 2 S 3 and P-In 2 S 3 samples are measured to be 0.21 and 0.48 mA cm −2 , as shown in Figure 5 e, and the J abs of the In 2 S 3 and P-In 2 S 3 samples are calculated to be 0.51 and 0.85 mA cm −2 , respectively.…”

Synergistic Use of a Solid Solution and a Cocatalyst on CoxCd1–xS/NiyFe1–y-LDH for Efficient and Stable Photoelectrochemical Performance

“…Therefore, the bulk charge separation efficiency (η inj ) and the photoanode/electrolyte interface separation efficiency (η sep ) of the samples are determined to further evaluate its PEC activity. Afterward, the η inj and η sep are calculated by the following eqs ,, and where J abs means the photocurrent derived by presuming 100% conversion of the light-absorbing into photocurrent density and J sulfite represents the photocurrent density measured of the photoelectrode in 0.25 M Na 2 SO 3 and 0.35 M Na 2 S mixed sacrificial solution (Figure S3b).…”

Tailored BiVO4/In2O3 nanostructures with boosted charge separation ability toward unassisted water splitting

“…Also, introduction of a proper PV cell, which can provide a sufficiently large photovoltage with only light transmitted through the BiVO 4 -based photoanode, is essential to driving bias-free PEC water splitting and achieving high STH conversion efficiency. 6,10,26,27 Herein, we aim to explore new BiVO 4 -based heterostructures exceeding previous best records of NiFeO x /BiVO 4 / WO 3 photoanodes 2,15,[28][29][30] and implement unbiased water splitting using a PV-PEC tandem cell. We first introduce indium oxide (In 2 O 3 ) nanorods (NRs) with high electrical conductivity as an effective electron transport layer (ETL) to overcome the limitations of WO 3 such as a relatively positive flat band potential of about 0.4 V RHE , causing potential energy losses for electrons and limiting the photovoltage of the total photoelectrodes.…”