Dynamic semiconductor-electrolyte interface for sustainable solar water splitting over 600 hours under neutral conditions

Abstract

Photoelectrochemical (PEC) water splitting that functions in pH-neutral electrolyte attracts increasing attention to energy demand sustainability. Here, we propose a strategy to in situ form a NiB layer by tuning the composition of the neutral electrolyte with the additions of nickel and borate species, which improves the PEC performance of the BiVO 4 photoanode. The NiB/BiVO 4 exhibits a photocurrent density of 6.0 mA cm −2 at 1.23 V RHE with an onset potential of 0.2 V RHE under 1 sun illumination. The photoanode displays a photostability of over 600 hours in a neutral electrolyte. The additive of Ni 2+ in the electrolyte, which efficiently inhibits the dissolution of NiB, can accelerate the photogenerated charge transfer and enhance the water oxidation kinetics. The borate species with B─O bonds act as a promoter of catalyst activity by accelerating proton-coupled electron transfer. The synergy effect of both species suppresses the surface charge recombination and inhibits the photocorrosion of BiVO 4 .

Improving the photoelectrochemical water splitting performance of CuO photocathodes using a protective CuBi2O4 layer

“…5 , the photocurrent of the photocathode with CuBi 2 O 4 layer shows two times higher than that of the photocathode without CuBi 2 O 4 . The photocurrent density of both photocathodes decreased rapidly at first ~300 s and then gradually stabilized during the stability test, indicating that the semiconductor-electrolyte interface was affected initially 40 ; after a period of adaptation with medium, the photocathode gradually stabilizes. Morphology change of photocathode S15450 is given in Fig.…”

Interface-Engineered Ni-Coated CdTe Heterojunction Photocathode for Enhanced Photoelectrochemical Hydrogen Evolution

“…Although much research effort has been dedicated to the investigation of different semiconductor photoelectrodes, 7−20 it is still very challenging to develop a low-cost, robust, and highly efficient semiconductor photoelectrode to enable a practical solar hydrogen production. 21,22 Cadmium telluride (CdTe) is an attractive candidate for hydrogen production via PEC water splitting due to its excellent optical absorption characteristics and band structure. 23−29 As a direct semiconductor with a band gap of 1.5 eV, CdTe exhibits a wide range absorption from ultraviolet to infrared sunlight (until 830 nm) and a high absorption coefficient of >10 4 cm −1 at the wavelengths smaller than 800 nm.…”

“…Solar-driven PEC water splitting provides a sustainable and storable energy source assisting in reducing society’s dependence on fossil fuels, consequently reducing CO 2 emissions and improving the ecological environment. − The key part of the PEC water splitting cell is the semiconductor photoelectrode, which is required to efficiently absorb and convert solar energy into electrons and holes. Although much research effort has been dedicated to the investigation of different semiconductor photoelectrodes, − it is still very challenging to develop a low-cost, robust, and highly efficient semiconductor photoelectrode to enable a practical solar hydrogen production. , …”

“…Although much research effort has been dedicated to the investigation of different semiconductor photoelectrodes, 7 − 20 it is still very challenging to develop a low-cost, robust, and highly efficient semiconductor photoelectrode to enable a practical solar hydrogen production. 21 , 22 …”

Surface Rh-Boosted Photoelectrochemical Water Oxidation of α-Fe2O3 by Reduced Overpotential in the Rate-Determining Step

“…There has been an increasing demand for establishing catalytic systems with high efficiency and excellent performance for hydrogen generation as an environmental energy source. The photoelectrochemical (PEC) water splitting is a promising solution due to its sustainability and efficiency. , Metal oxide photoanodes are attractive candidates for PEC water oxidation because of their remarkable electrical properties, low cost, and facile synthesis. − In particular, hematite (α-Fe 2 O 3 ) is regarded as a suitable photoanode material due to its excellent chemical stability, lack of photocorrosion, facile synthesis, low toxicity, and abundance in nature. − However, the limited photocatalytic efficiency of pure hematite restricts its practical applications due to its fast rate of recombination, low electron and hole mobility, short mean-free carrier paths, and sluggish kinetics at the photoelectrode/electrolyte interface. − Therefore, bandgap engineering, , surface engineering, − and wide-range-absorbing sensitizer , integration have been adopted to improve the current PEC performance of α-Fe 2 O 3 photoelectrodes.…”