Photoelectrochemical study of p-GaP(100)|ZnO|AuNP devices: strategies for enhanced electron transfer and aqueous catalysis

Williams, Owen M.; Shi, Justin; Rose, Michael J.

doi:10.1039/c6cc00703a

Cited by 5 publications

(2 citation statements)

References 41 publications

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“…Many recent proposals deal with the use of the GaP semiconductor as a photoelectrode in PEC devices, especially because its bandgap (2.26 eV) is larger than the 1.73 eV photopotential needed for water splitting . Using this idea, demonstrations of GaP‐based PEC devices and descriptions of the physics/chemistry of the standard GaP surface, its interaction with water and hydrogen generation were reported. To enhance conversion efficiency of GaP‐based PEC devices, strategies like surface functionalization, use of plasmon resonant nanostructures, or integration of nanowires were considered.…”

Section: Introductionmentioning

confidence: 99%

A Stress‐Free and Textured GaP Template on Silicon for Solar Water Splitting

Lucci

Charbonnier

Vallet

et al. 2018

Adv Funct Materials

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This work shows that a large-scale textured GaP template monolithically integrated on Si can be developed by using surface energy engineering, for watersplitting applications. The stability of (114)A facets is first shown, based on scanning tunneling microscopy images, transmission electron microscopy, and atomic force microscopy. These observations are then discussed in terms of thermodynamics through density functional theory calculations. A stressfree nanopatterned surface is obtained by molecular beam epitaxy, composed of a regular array of GaP (114)A facets over a 2 in. vicinal Si substrate. The advantages of such textured (114)A GaP/Si template in terms of surface gain, band lineups, and ohmic contacts for water-splitting applications are finally discussed.photosemiconductor catalysts [4,5] is definitely the most promising tech nology for the near future with potentially plethora of hydrogen provided in a clean and sustainable manner. Many recent proposals deal with the use of the GaP semiconductor as a photoelectrode in PEC devices, [6] especially because its bandgap (2.26 eV) is larger than the 1.73 eV photo potential needed for water splitting. [7] Using this idea, demonstrations of GaP based PEC devices [8][9][10][11] and descriptions of the physics/chemistry of the standard GaP surface, [12] its interaction with water [13,14] and hydrogen generation [15] were reported. To enhance conversion efficiency of GaP based PEC devices, strategies like surface functionalization, [10] use of plasmon resonant nanostructures, [16] or integration of nanowires [17] were considered. Meanwhile, it was demonstrated recently that the texturation of surfaces at the electrode level greatly enhances the efficiency of BiVO 4 photoanodes in PEC devices. [18] Structuration of semiconductor surfaces can be per formed by lithography techniques, [19] chemical processes, [20,21] nanowires, or by a selforganization during the epitaxial process of the material itself. [22] This last approach is usually driven by crystal strainrelief processes; it simplifies the postgrowth device processing but does not offer large degrees of freedom,

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Section: Introductionmentioning

confidence: 99%

A Stress‐Free and Textured GaP Template on Silicon for Solar Water Splitting

Lucci

Charbonnier

Vallet

et al. 2018

Adv Funct Materials

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“…With the band diagram in Figure 4c, we can calculate the transmission coefficient T at different incident energies E. The incident energy equals the energy difference between photon energy and the bandgap of GaP (2.26 eV). 40 Considering the photon energy of visible light is in between 1.59 and 3.26 eV, the incident energy for carriers in the visible light region therefore varies from 0 to 1 eV. As the hole and electron tunneling are different in behavior, we discuss them separately in the following text.…”

Section: Resultsmentioning

confidence: 99%

CO₂ Photoreduction via Quantum Tunneling: Thin TiO₂-Coated GaP with Coherent Interface To Achieve Electron Tunneling

Liu

2019

ACS Catal.

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Photocatalysts for CO2 photoreduction such as GaP often suffer from poor stability due to a high reduction environment as required for CO2 reduction, e.g., −1.9 V vs SCE to reach the current density of 10 mA/cm2 at pH = 5.8 on p-GaP (Nature1978275115). The coating with stable oxides appears to be a promising solution, but many fundamental aspects such as the epitaxial relation between materials, the coating layer thickness, and the consequent photoactivity remain unknown. Here, using a thin TiO2-coated GaP as a model system, we have systematically investigated the dependence of photoactivity upon the deposition of TiO2 on GaP surfaces. By combining the modified phenomenological theory of Martensitic crystallography and a stochastic surface walking global search, we resolve the atomic-level structures of the interface between GaP and TiO2, a set of coherent interfaces between TiO2 and GaP ((001)TiO2//(100)GaP, (101)TiO2//(110)GaP, and (112)TiO2//(100)GaP). Due to the negligible interface strain, the epitaxial TiO2 coating layer is found to be as stable as bulk TiO2 even with a thickness below 1 nm, suggesting the presence of the well-ordered interface is a critical condition for promoting electron–hole separation in photocatalysis. We demonstrate that a photoelectron generated from GaP bulk can readily tunnel through the thin TiO2 layer (0.5–3 nm) without significant decay, which can decrease the CO2 reduction barrier significantly by 1.02 eV as compared to that without electron tunneling; alternatively, the photoelectron may also undergo lattice hopping to the TiO2 surface to promote hydrogen evolution as required in water splitting. Our results rationalize the recent finding that the high CO2 reduction ability of TiO2 coated GaP at a critical thickness (<10 nm). Using the theoretical framework developed here, we predict that the TiO2 coating strategy could be extended naturally to a range of photoabsorbing materials, including zincblende semiconductors and organic–inorganic hybrid halide perovskites, which can achieve a coherent interface and exhibit photoactivity toward water splitting and CO2 reduction.

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Novel cathodic photoelectrochemical immnuosensor with high sensitivity based on 3D AuNPs/ZnO/Cu2O heterojunction nanowires

Fan

Cui

et al. 2019

Electrochimica Acta

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Photoelectrochemical study of p-GaP(100)|ZnO|AuNP devices: strategies for enhanced electron transfer and aqueous catalysis

Cited by 5 publications

References 41 publications

A Stress‐Free and Textured GaP Template on Silicon for Solar Water Splitting

A Stress‐Free and Textured GaP Template on Silicon for Solar Water Splitting

CO₂ Photoreduction via Quantum Tunneling: Thin TiO₂-Coated GaP with Coherent Interface To Achieve Electron Tunneling

Novel cathodic photoelectrochemical immnuosensor with high sensitivity based on 3D AuNPs/ZnO/Cu2O heterojunction nanowires

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Photoelectrochemical study of p-GaP(100)|ZnO|AuNP devices: strategies for enhanced electron transfer and aqueous catalysis

Cited by 5 publications

References 41 publications

A Stress‐Free and Textured GaP Template on Silicon for Solar Water Splitting

A Stress‐Free and Textured GaP Template on Silicon for Solar Water Splitting

CO2 Photoreduction via Quantum Tunneling: Thin TiO2-Coated GaP with Coherent Interface To Achieve Electron Tunneling

Novel cathodic photoelectrochemical immnuosensor with high sensitivity based on 3D AuNPs/ZnO/Cu2O heterojunction nanowires

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Product

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About

CO₂ Photoreduction via Quantum Tunneling: Thin TiO₂-Coated GaP with Coherent Interface To Achieve Electron Tunneling