The synergism of Co3O4 co-catalysis and Pt-doping boosting hematite photoanode for efficient solar H2O2 synthesis

Wei, Yiqing; Liao, Aizhen; Zhu, Wenwu; Hou, Wentao; Zhang, Yongcai; Zheng, Yubing; Zhou, Baiquan; Yan, Yuxiang; He, Huichao; Zhou, Xin; Zhou, Yong; Zou, Zhigang

doi:10.1016/j.cej.2023.145384

Cited by 11 publications

(4 citation statements)

References 45 publications

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“…It is of the utmost importance to develop green, sustainable, and clean energy resources due to the depletion of nonrenewable fossil fuels and the adverse consequences of fossil fuels on the environment. Photoelectrochemical (PEC) water splitting is widely viewed as a potentially fruitful method for producing clean and carbon-free H 2 in future energy portfolios. − Among various metal oxides that can be used as a photoanode material, hematite (α-Fe 2 O 3 ; HT) has been described as an excellent candidate for PEC water oxidation due to its appropriate bandgap (∼2.0 eV), natural abundance, low cost, and high chemical stability. − The high recombination rate of photogenerated electron–hole pairs in bulk or at the surface of HT is likely responsible for hampering its experimental performance. , To address these issues, ion doping and surface modifications have been proposed to lower the carrier recombination rate and increase the reaction rate. − …”

Section: Introductionmentioning

confidence: 99%

Unveiling the Significance of Diverse Valence State Second Dopants on Hf-Doped Fe₂O₃ Photoanodes for Enhanced Photoelectrochemical Water Splitting

Anushkkaran,

Kwon,

Koh

et al. 2024

ACS Sustainable Chem. Eng.

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Hematite (α-Fe 2 O 3 )-based photoanodes offer great potential for use in solar hydrogen production as part of efforts to construct a sustainable and renewable energy economy based on photoelectrochemical (PEC) water splitting. A co-doping modification is of the utmost significance for improving PEC performance. To develop an efficient photoanode, a comprehensive grasp of co-dopants with diverse valence states is necessary. Herein, we describe a hydrothermal and dip-coating approach to the fabrication of Hfdoped Fe 2 O 3 (Hf-HT) photoanodes co-doped with Be 2+ , Al 3+ , Si 4+ , and Nb 5+ and evaluate the influence of each co-dopant on PEC performance. The PEC characteristic results revealed that Be 2+ and Al 3+ co-dopants enhanced surface charge separation efficiency, thus accelerating charge transfers at the photoanode−electrolyte interface. Meanwhile, the PEC performance of the Hf-HT photoanode co-doped with Nb did not significantly improve because of the thick Nb 2 O 5 overlayer. However, the use of a Si 4+ co-dopant improved the bulk properties of the photoanode. An optimized Hf-HT photoanode co-doped with Be achieved a photocurrent density of 1.98 mA/cm 2 at 1.23 V RHE . This demonstrates that ex situ co-doping can have both positive and negative impacts on the PEC activity of photoelectrodes, and the co-dopants used to accomplish the desired outcomes should be considered in detail.

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Section: Introductionmentioning

confidence: 99%

Unveiling the Significance of Diverse Valence State Second Dopants on Hf-Doped Fe₂O₃ Photoanodes for Enhanced Photoelectrochemical Water Splitting

Anushkkaran,

Kwon,

Koh

et al. 2024

ACS Sustainable Chem. Eng.

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“…The disordered SnTiO x overlayer acted as potential active sites, and thermal annealing treatment of Fe 2 O 3 introduced numerous oxygen vacancies with good electron transfer efficiency. Zhou and his colleagues 24 designed the Co 3 O 4 cocatalyst and Pt doping on the Fe 2 O 3 photoanode with an H 2 O 2 production Faraday efficiency of 77.38% and a yield of 0.073 μmol cm −2 at 1.0 V RHE . The Pt doping induced defect sites to enhance bulk carrier density and mobility, while the conductive Co 3 O 4 facilitated to obtain two-electron water oxidation for high selectivity and to decrease the decomposition of H 2 O 2 .…”

Section: ■ Introductionmentioning

confidence: 99%

Enhanced Charge Transfer via Heterogeneous Doping Promotes Hematite Photoelectrodes for Efficient Solar H₂O₂ Synthesis

Guo,

Bai,

Gao

et al. 2024

ACS Catal.

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Photoelectrochemical (PEC) water splitting into hydrogen peroxide (H 2 O 2 ) and hydrogen (H 2 ) is a promising alternative to energy and environmentally intensive production. Bulk electronic and surface structures affect the charge transport efficiency and catalytic activity of the photoelectrode. Herein, we design and investigate a hematite (Fe 2 O 3 ) nanorod photoelectrode with hafnium and titanium binary dopants for highly selective H 2 O 2 production. The resultant photoanode shows a H 2 O 2 yield of 0.41 μmol min −1 cm −2 at 1.5 V RHE with a Faradaic efficiency of 72.2%. Experimental investigations and theoretical calculations demonstrate the synergistic effect of Hf and gradient Ti doping on the hematite for the promising H 2 O 2 performance. Hf doping effectively improves the crystallinity of Fe 2 O 3 , which favors improving the charge transport and reducing the charge recombination. Gradient Ti doping inhibits the collapse of the nanorod structure, increases the specific surface area, and introduces a large number of active sites on the surface. Ti-and Hf-codoped Ti/Hf:Fe 2 O 3 photoanode improves the kinetics of H 2 O 2 generation, leading to the high selectivity for H 2 O 2 production and suppression of O 2 production. This work provides the importance of hematite-based photoanodes toward the regulation of competition reactions for H 2 O 2 production.

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“…[14][15][16] However, due to its sluggish carrier transport in bulk and slow carrier transfer at semiconductor-liquid junctions (SCLJs), the PEC efficiency of α-Fe 2 O 3 is far from the practical application under AM 1.5G solar simulated light. [17][18][19] Element doping can change the energy band structure of Fe 2 O 3 , [20][21][22][23][24][25] increase the carrier concentration and carrier lifetime, improve the electrical conductivity, and increase the electric field at the electrode/electrolyte interface to inhibit the carrier recombination. [15,26,27] Noticeably, doping with elements Pt can improve the charge transfer characteristics in the bulk of the Fe 2 O 3 , and thus resulted in a record-breaking performance at that time.…”

Section: Introductionmentioning

confidence: 99%

“…Element doping can change the energy band structure of Fe 2 O 3 , [ 20–25 ] increase the carrier concentration and carrier lifetime, improve the electrical conductivity, and increase the electric field at the electrode/electrolyte interface to inhibit the carrier recombination. [ 15,26,27 ] Noticeably, doping with elements Pt can improve the charge transfer characteristics in the bulk of the Fe 2 O 3 , and thus resulted in a record‐breaking performance at that time.…”

Section: Introductionmentioning

confidence: 99%

Boosting the Solar Water Oxidation Performance of Fe₂O₃ Photoanode via Embedding Laser‐Generated Pt Nanocrystals

Li,

Jian,

Wang

et al. 2024

Small Science

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α‐Fe2O3 with suitable band structure, good chemical stability, and easy preparation, is a potential photoanode material. However, the key to enhance the performance of α‐Fe2O3 photoanode is to improve the transport characteristics of bulk carriers. It is expected to form a Schottky barrier to improve the carrier separation efficiency by embedding metal nanoparticles into the matrix, but the process is still challenging. Herein, a strategy of forming the Schottky barrier is shown to improve bulk carrier transport dynamics by embedding laser‐generated Pt nanocrystals in α‐Fe2O3 photoanode, which achieves photocurrent densities of up to 1.16 mA cm−2 at 1.23 VRHE (from original 0.21 mA cm−2). This work provides another way to promote the carrier transfer and separation of α‐Fe2O3, which is of great significance to improve the photoelectrochemical water splitting performance.

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The synergism of Co3O4 co-catalysis and Pt-doping boosting hematite photoanode for efficient solar H2O2 synthesis

Cited by 11 publications

References 45 publications

Unveiling the Significance of Diverse Valence State Second Dopants on Hf-Doped Fe₂O₃ Photoanodes for Enhanced Photoelectrochemical Water Splitting

Unveiling the Significance of Diverse Valence State Second Dopants on Hf-Doped Fe₂O₃ Photoanodes for Enhanced Photoelectrochemical Water Splitting

Enhanced Charge Transfer via Heterogeneous Doping Promotes Hematite Photoelectrodes for Efficient Solar H₂O₂ Synthesis

Boosting the Solar Water Oxidation Performance of Fe₂O₃ Photoanode via Embedding Laser‐Generated Pt Nanocrystals

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The synergism of Co3O4 co-catalysis and Pt-doping boosting hematite photoanode for efficient solar H2O2 synthesis

Cited by 11 publications

References 45 publications

Unveiling the Significance of Diverse Valence State Second Dopants on Hf-Doped Fe2O3 Photoanodes for Enhanced Photoelectrochemical Water Splitting

Unveiling the Significance of Diverse Valence State Second Dopants on Hf-Doped Fe2O3 Photoanodes for Enhanced Photoelectrochemical Water Splitting

Enhanced Charge Transfer via Heterogeneous Doping Promotes Hematite Photoelectrodes for Efficient Solar H2O2 Synthesis

Boosting the Solar Water Oxidation Performance of Fe2O3 Photoanode via Embedding Laser‐Generated Pt Nanocrystals

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Unveiling the Significance of Diverse Valence State Second Dopants on Hf-Doped Fe₂O₃ Photoanodes for Enhanced Photoelectrochemical Water Splitting

Unveiling the Significance of Diverse Valence State Second Dopants on Hf-Doped Fe₂O₃ Photoanodes for Enhanced Photoelectrochemical Water Splitting

Enhanced Charge Transfer via Heterogeneous Doping Promotes Hematite Photoelectrodes for Efficient Solar H₂O₂ Synthesis

Boosting the Solar Water Oxidation Performance of Fe₂O₃ Photoanode via Embedding Laser‐Generated Pt Nanocrystals