Regulating the hole transfer from CuWO4 photoanode to NiWO4 electrocatalyst for enhanced water oxidation performance

Fan, Liya; Sunarso, Jaka; Zhang, Xiao; Xiong, Xianqiang; He, Li; Luo, Liqiang; Wang, Fangling; Fan, Ziwei; Wu, Chenglin; Han, Deman; Wong, Ngie Hing; Wang, Yong; Chen, Guihua; Chen, Wei

doi:10.1016/j.ijhydene.2022.04.148

Cited by 14 publications

(7 citation statements)

References 54 publications

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“…Nickel tungstate NiWO 4 , with a partially occupied d electron shell (3d 8 ), is an indirect bandgap semiconductor, and its absorption edge falls in the visible region. , NiWO 4 has a smaller bandgap compared to the tungstates with empty or full d electron shells and shows a wider application as scintillation crystals. However, multiple-absorption peak characteristics of NiWO 4 , including the fundamental band for ligand–metal charge transfer (LMCT) in WO 6 octahedron and the bands for Ni 2+ d–d intraband transitions, lead to its long fluorescence decay time. − It has been demonstrated that the absorption intensity was stronger when the absorption bands for the Ni 2+ d–d intraband transitions were in proximity to the fundamental band . Therefore, reducing the energy difference between the fundamental band and the Ni 2+ d–d transition bands is a critical issue for improving the optical properties of NiWO 4 .…”

Section: Introductionmentioning

confidence: 99%

Effects of High Pressure on the Bandgap and the d–d Crystal Field Transitions in Wolframite NiWO₄

Zhou

Shao

et al. 2023

J. Phys. Chem. C

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The pressure effects on the optical and structural properties of NiWO4 have been studied experimentally and theoretically. The fundamental bandgap decreases with a pressure coefficient of −12.0 ± 0.2 meV/GPa. Meanwhile, the Ni2+ d–d transition energies increase at a rate of 7.4–14.8 meV/GPa. Therefore, the energy differences between the fundamental band and the Ni2+ d–d transition bands gradually decrease under pressure, which is beneficial to improve its optical performance. These optical phenomena are associated with structural variations. The shrinkage of the WO6 octahedron enhances the hybridization between the W 5d and O 2p orbitals, resulting in bandgap reduction. The pressure-induced enhancement of the NiO6 octahedral symmetry increases the crystal field splitting, thereby yielding increases in the Ni2+ d–d intraband transition energies. Besides, a pressure-induced structural phase transition is also observed around 20.0 GPa by both angle-dispersive synchrotron X-ray diffraction (ADXRD) and Raman experiments. This study provides valuable insight into the electron–lattice coupling of NiWO4 under compression and an effective way to modulate the electronic structure and optical properties of isomorphic wolframite materials.

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Section: Introductionmentioning

confidence: 99%

Effects of High Pressure on the Bandgap and the d–d Crystal Field Transitions in Wolframite NiWO₄

Zhou

Shao

et al. 2023

J. Phys. Chem. C

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“…It is not difficult to find that the binding energy of Ni in GN also moves in the orientation of improving binding energy. Figure 4(d) shows us the fine spectrum of W 4f, which also shows that the characteristic peak also removes in the orientation of improving binding energy [45]. According to the aforementioned analysis, we can draw a preliminary conclusion that the direction of electron transfer after catalyst contact is from NiWO 4 to GDY.…”

Section: Xps Analysismentioning

confidence: 78%

Graphdiyne (C_nH_2n−2)/NiWO₄ self-assembled p–n junction characterized with in situ XPS for efficient photocatalytic hydrogen production

Zhang,

Lei,

Jin

2023

2D Mater.

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As is well known, how to deeply understand the charge separation and charge transfer capabilities of catalysts, as well as how to optimize these capabilities of catalysts to improve hydrogen production performance, remains a huge challenge. In recent years, a new type of carbon material graphdiyne (GDY) has been proposed. GDY acetylene has a special atomic arrangement that graphene does not have a two-dimensional network of sp2 and sp conjugated intersections makes it easier to construct active sites and improve photocatalytic ability. In addition, GDY also has the advantage of adjusting the bandgap of other catalysts and inhibiting carrier recombination, making it more prone to hydrogen evolution reactions. In addition to using mechanical ball milling to produce GDY, NiWO4 without precious metals was also prepared. The sheet-like structure of GDY in the composite catalyst provides a anchoring site and more active sites for the granular NiWO4. And the composite catalyst fully enhances the good conductivity of GDY and its unique ability to enhance electron transfer, greatly improving the ability of NiWO4 as a single substance. Through in-situ x-ray photoelectron spectrometer, it was demonstrated that a p–n heterojunction was constructed between GDY and NiWO4 in the composite catalyst, further enhancing the synergistic effect between the two, resulting in a hydrogen production rate of 90.92 μmol for the composite catalyst is 4.56 times higher than that of GDY and 4.97 times higher than that of NiWO4, respectively, and the stability of the composite catalyst is significantly higher than that of each single catalyst.

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“…Electrodeposition [14,21] Thermal conversion [39,40] Sol-gel method [26,29,35] Hydrothermal [25] Electrodeposition (J ph 0.2 mA/cm 2 at 1.23 V RHE ) [21] ALD [30] Thermal conversion (J ph 0.33 mA/cm 2 at 1.23 V RHE ) [24] CVD [23] Ultrasonic spray pyrolysis [28] Impulse magnetron co-sputtering [32] PLD [31] Sol-gel (J ph 0.5mA/cm 2 Mo 6+ [44] Mo solid solution Mo 6+ [45][46][47][48] Red shift of photoresponse (from 550 nm to 600 nm) [45] CuW 0.35 Mo 0.65 O 4 /FTO (J ph 1.0 mA/cm 2 at 1.23 V RHE for SA oxidation) [46] Heterojunction and electron transfer layer WO 3 (flat) [49] WO 3 (nanorod) [39] WO 3 (urchin like) [50] SnO 2 [26] BiVO 4 [51] CuWO 4 /flat WO 3 /FTO. ~4 times increment (J ph 0.55 mA/cm 2 at 1.23 V RHE ) [49] Electrocatalyst Co-Pi [26,52,53] Co 3 O 4 [18] FeCoO x [54] MnPO 4 [55] NiWO 4 [56] NiFeO x [57] P-type sulfide (MoS 2 , NbS 2 , NiS x ) [44] MnNCN [58] Ni-Pi [59] Ag [60] Co-Pi/CuWO 4 /FTO, 30% increment (J ph 0.4 mA/cm 2 at 0.6 V Ag/AgCl ) [52] IrCo-Pi [61] Post-treatment H 2 treatment…”

Section: Synthesis Methodsmentioning

confidence: 99%

Emergent CuWO4 Photoanodes for Solar Fuel Production: Recent Progress and Perspectives

Lee,

Kim,

Lee

2023

Catalysts

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Solar fuel production using a photoelectrochemical (PEC) cell is considered as an effective solution to address the climate change caused by CO2 emissions, as well as the ever-growing global demand for energy. Like all other solar energy utilization technologies, the PEC cell requires a light absorber that can efficiently convert photons into charge carriers, which are eventually converted into chemical energy. The light absorber used as a photoelectrode determines the most important factors for PEC technology—efficiency, stability, and the cost of the system. Despite intensive research in the last two decades, there is no ideal material that satisfies all these criteria to the level that makes this technology practical. Thus, further exploration and development of the photoelectode materials are necessary, especially by finding a new promising semiconductor material with a suitable band gap and photoelectronic properties. CuWO4 (n-type, Eg = 2.3 eV) is one of those emerging materials that has favorable intrinsic properties for photo(electro)catalytic water oxidation, yet it has been receiving less attention than it deserves. Nonetheless, valuable pioneering studies have been reported for this material, proving its potential to become a significant option as a photoanode material for PEC cells. Herein, we review recent progress of CuWO4-based photoelectrodes; discuss the material’s optoelectronic properties, synthesis methods, and PEC characteristics; and finally provide perspective of its applications as a photoelectrode for PEC solar fuel production.

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Regulating the hole transfer from CuWO4 photoanode to NiWO4 electrocatalyst for enhanced water oxidation performance

Cited by 14 publications

References 54 publications

Effects of High Pressure on the Bandgap and the d–d Crystal Field Transitions in Wolframite NiWO₄

Effects of High Pressure on the Bandgap and the d–d Crystal Field Transitions in Wolframite NiWO₄

Graphdiyne (C_nH_2n−2)/NiWO₄ self-assembled p–n junction characterized with in situ XPS for efficient photocatalytic hydrogen production

Emergent CuWO4 Photoanodes for Solar Fuel Production: Recent Progress and Perspectives

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Regulating the hole transfer from CuWO4 photoanode to NiWO4 electrocatalyst for enhanced water oxidation performance

Cited by 14 publications

References 54 publications

Effects of High Pressure on the Bandgap and the d–d Crystal Field Transitions in Wolframite NiWO4

Effects of High Pressure on the Bandgap and the d–d Crystal Field Transitions in Wolframite NiWO4

Graphdiyne (CnH2n−2)/NiWO4 self-assembled p–n junction characterized with in situ XPS for efficient photocatalytic hydrogen production

Emergent CuWO4 Photoanodes for Solar Fuel Production: Recent Progress and Perspectives

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Product

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Effects of High Pressure on the Bandgap and the d–d Crystal Field Transitions in Wolframite NiWO₄

Effects of High Pressure on the Bandgap and the d–d Crystal Field Transitions in Wolframite NiWO₄

Graphdiyne (C_nH_2n−2)/NiWO₄ self-assembled p–n junction characterized with in situ XPS for efficient photocatalytic hydrogen production