Nitrogen-incorporation activates NiFeOx catalysts for efficiently boosting oxygen evolution activity and stability of BiVO4 photoanodes

Abstract

Developing low-cost and highly efficient catalysts toward the efficient oxygen evolution reaction (OER) is highly desirable for photoelectrochemical (PEC) water splitting. Herein, we demonstrated that N-incorporation could efficiently activate NiFeOx catalysts for significantly enhancing the oxygen evolution activity and stability of BiVO4 photoanodes, and the photocurrent density has been achieved up to 6.4 mA cm−2 at 1.23 V (vs. reversible hydrogen electrode (RHE), AM 1.5 G). Systematic studies indicate that the partial substitution of O sites in NiFeOx catalysts by low electronegative N atoms enriched the electron densities in both Fe and Ni sites. The electron-enriched Ni sites conversely donated electrons to V sites of BiVO4 for restraining V5+ dissolution and improving the PEC stability, while the enhanced hole-attracting ability of Fe sites significantly promotes the oxygen-evolution activity. This work provides a promising strategy for optimizing OER catalysts to construct highly efficient and stable PEC water splitting devices.

Flexoelectric Domain Walls Originated from Structural Phase Transition in Epitaxial BiVO4 Films

“…For example, band structure engineering technique based on heterojunction promotes carrier‐separation ability, such as BaTiO 3 /BVO ferroelectric‐semiconductor hybrid [ 32 ] or FeOOH/BVO heterojunction. [ 33 ] Beside, tuning oxidation/reduction of V OV 5+ / V OV 4+ states in BVO [ 34 ] or modulation of oxygen vacancy by hybrid structure [ 35 ] provides insights to modify carrier trapping/extracting procedure. In addition, ferroelectric‐semiconductor hybrid (Iodide‐doped BiVO 4 /BaTiO 3 ) [ 36 ] could also be applied to piezophototronic field, which is an coupling effect between photoexcitation and piezopotential.…”

Photoelectrochemical Performance Improving Mechanism: Hybridization Appearing at the Energy Band of BiVO4 Photoanode by Doped Quantum Layers Modification

“…Then, the photoanode achieved the photocurrent densities of 4.80 and 5.18 mA cm -2 at 1.23 V (vs RHE) in 1 m boracic acid buffer electrolyte without and with Na 2 SO 3 sacrificial agent, respectively. However, if the same simulated sunlight (without UV% cutting in the total light energy) of the recent reported BiVO 4 -based works is employed, [14,15,[25][26][27][28][29][30][31] as shown in Figure S8 (Supporting Information), the highest photocurrent density of 6.47 mA cm -2 can be achieved in Na 2 SO 3 sacrificial electrolyte at 1.23 V (versus RHE). As shown in Table S1 (Supporting Information), comparing with similar state-of-the-art BiVO 4 based photoanodes, NiFeOx/Rh-STO/Ni-ZnO/BVO photoanode presented in this work achieves a recorded photocurrent density for PEC water oxidation with the same tested condition.…”

A self-adaptive semiconductor–liquid junction for highly active and stable solar water splitting

“…Hitherto, a more intractable challenge has been to optimize the surface/interface of the photoanodes via constructing a highly active and stable SCLJ with an aim to accelerate the water oxidation reaction kinetics and inhibit photocorrosion. 18,19…”

“…Hitherto, a more intractable challenge has been to optimize the surface/interface of the photoanodes via constructing a highly active and stable SCLJ with an aim to accelerate the water oxidation reaction kinetics and inhibit photocorrosion. 18,19 The deposition of various oxygen evolution reaction (OER) cocatalysts, such as transition metal oxides and (oxy)hydroxides, on the surface of photoanodes has been reported to be of great assistance in activating the SCLJ by expediting surface reaction kinetics and charge transfer at the photoelectrode/electrolyte interface. 20,21 For instance, surface modication of cobalt-iron hydroxide nanosheets on BiVO 4 achieves a three-fold higher photocurrent density by accelerating the water oxidation kinetics at the SCLJ.…”