Regulating the Spin State of Fe<sup>III</sup> by Atomically Anchoring on Ultrathin Titanium Dioxide for Efficient Oxygen Evolution Electrocatalysis

Shen, Guoqiang; Zhang, Rongrong; Pan, Lun; Hou, Fang; Zhao, Yingjie; Shen, Zeyu; Mi, Wenbo; Shi, Chengxiang; Wang, Qingfa; Zhang, Xiangwen; Zou, Ji‐Jun

doi:10.1002/anie.201913080

Cited by 275 publications

(171 citation statements)

References 38 publications

Supporting

Mentioning

166

Contrasting

Order By: Relevance

“…(α‐Fe 2 O 3 ), a mineral with high abundance and stability, has been proven to be active as an electrocatalyst. [ 26,27 ] However, α‐Fe 2 O 3 is seldom used for oxygen reduction in fuel cells because of its sluggish O 2 adsorption and weak capacity for cracking OO bond, [ 28,29 ] suggesting that it may be a potential candidate for the reduction of O 2 to H 2 O 2 . In particular, the {001} facet is expected to be selective for H 2 O 2 production because this surface, which is covered with oxygen atoms, is weak in terms of its capacity for O 2 adsorption and OO cleavage.…”

Section: Introductionmentioning

confidence: 99%

Engineering Facets and Oxygen Vacancies over Hematite Single Crystal for Intensified Electrocatalytic H₂O₂ Production

Gao

Pan

et al. 2020

Adv Funct Materials

Self Cite

123

View full text Add to dashboard Cite

Hydrogen peroxide is a highly valuable chemical, and electrocatalytic oxygen reduction towards H2O2 offers an alternative method for safe on‐site applications. Generally, low‐cost hematite (α‐Fe2O3) is not recognized as an efficient electrocatalyst because of its inert nature, but it is herein reported that α‐Fe2O3 can be endowed with high catalytic activity and selectivity via the engineering of facets and oxygen vacancies. Density‐functional theory (DFT)calculations predict that the {001} facet is intrinsically selective for H2O2 production, and that oxygen vacancies can trigger the high activity, providing sites for O2 adsorption and protonation, stabilizing the *OOH intermediate, and preventing cleavage of the OO bond. The synthesized oxygen‐defective α‐Fe2O3 single crystals with exposed {001} facets achieve high selectivities for H2O2 of >90%, >88%, and >95% in weakly acidic, neutral, and alkaline electrolytes, respectively, and the H2O2 production rate reaches 454 mmol g−1cat h−1 at 0.1 V versus RHE under alkaline conditions. In an anion exchange membrane fuel cell, a maximum H2O2 production of 546.8 mmol L−1 with a high Faradaic efficiency of 80.5% is achieved. Thus, this work details a low‐cost catalyst feasible for H2O2 synthesis, and highlights the feasibility of theoretical catalyst design for practical applications.

show abstract

Section: Introductionmentioning

confidence: 99%

Engineering Facets and Oxygen Vacancies over Hematite Single Crystal for Intensified Electrocatalytic H₂O₂ Production

Gao

Pan

et al. 2020

Adv Funct Materials

Self Cite

123

View full text Add to dashboard Cite

show abstract

“…And the proposed kinetics are diverse: for spinel Co 3 O 4 , the tetrahedral (T d ) Co are regarded as OER active sites; for perovskite ABO 3 , the metal ion in octahedral (O h ) sites are identified as active sites for OER; for the complex oxides, both the T d metal and O h oxygen are proposed as the dominant active sites. [6][7][8][9][10][11] Molybdenum (Mo) based palmeirite oxides (A 2 Mo 3 O 8 , A = Fe, Co, Ni, et. al) with stable OER performance and high electronic conductivity have received increasing attention.…”

Section: Introductionmentioning

confidence: 99%

Coupling Magnetic Single‐Crystal Co₂Mo₃O₈ with Ultrathin Nitrogen‐Rich Carbon Layer for Oxygen Evolution Reaction

et al. 2020

View full text Add to dashboard Cite

Transition‐metal oxides as electrocatalysts for the oxygen evolution reaction (OER) provide a promising route to face the energy and environmental crisis issues. Although palmeirite oxide A2Mo3O8 as OER catalyst has been explored, the correlation between its active sites (tetrahedral or octahedral) and OER performance has been elusive. Now, magnetic Co2Mo3O8@NC‐800 composed of highly crystallized Co2Mo3O8 nanosheets and ultrathin N‐rich carbon layer is shown to be an efficient OER catalyst. The catalyst exhibits favorable performance with an overpotential of 331 mV@10 mA cm−2 and 422 mV@40 mA cm−2, and a full water‐splitting electrolyzer with it as anode catalyst shows a cell voltage of 1.67 V@10 mA cm−2 in alkaline. Combined HAADFSTEM, magnetic, and computational results show that factors influencing the OER performance can be attributed to the tetrahedral Co sites (high spin, t23e4), which improve the OER kinetics of rate‐determining step to form *OOH.

show abstract

“…As a result, the mass density of (100)‐oriented LaCoO 3 (87% IS) is 2.9 and 6.7 times higher than those of (110) and (111)‐oriented LaCoO 3 (31% IS and 48% IS). Currently, research efforts on spin states of catalysts are mainly based on the regulation of lattice planes, [ 139 ] heteroatom doping, [ 140–142 ] and material dimensions. [ 143–145 ] However, design and production of these catalysts are technically complicated.…”

Section: Magnetic Field‐assisted Electrocatalytic Her/oermentioning

confidence: 99%

Promoting Electrocatalytic Hydrogen Evolution Reaction and Oxygen Evolution Reaction by Fields: Effects of Electric Field, Magnetic Field, Strain, and Light

et al. 2020

View full text Add to dashboard Cite

promising alternative to fossil fuels. Water electrolysis by renewable resourcederived electricity represents a facile and green route to produce H 2. [1-13] Generally, the key to implement high-performance water splitting is to develop economically viable, efficient, and robust electrocatalysts to lower the activation potential barriers. Thus far, researchers have devoted extensive enthusiasm to the investigation of electrocatalysts. Currently, most efforts have been taken on the search for new materials, [14-16] regulation of morphology, [17] crystallinity, [18] facet, [19] component, [20-24] defect, [25,26] matter phase, [27,28] or the compositing of various materials with synergy. [29-36] However, the performances of emerging nonnoble electrocatalysts still lag behind those of noble ones. To address this issue, researchers have turned their attention beyond the electrocatalysts themselves. Field-assisted electrocatalysis is the electrocatalytic reaction proceeded in the presence of a field. It represents a promising methodology since it exerts an additional degree of freedom to engineer an electrochemical process. Inspiringly, indisputable improvements in electrocatalytic hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) have been implemented with the assist of various fields, including electric field, magnetic field, strain, and light. For example, the electrocatalytic HER of a MoS 2 nanosheet is markedly boosted by simply exploiting a back gate voltage of 5 V. [37] Its overpotential at −100 mA cm −2 is decreased from 240 to 38 mV. In addition, enhancement of alkaline water electrolysis is achieved by applying a moderate magnetic field (≤450 mT) to an electrocatalytic anode consists of highly magnetic electrocatalysts. [38] Its current density increments are beyond 100%. Furthermore, the HER activity of β-PdH x increases monotonically as the applied strain increases from 0% to 4.5%. [39] Lastly, an approximately threefold increase in current density of Au-MoS 2 for electrocatalytic HER is realized upon the illumination of IR light. [40] These results undoubtedly elucidate that applying a field during electrocataly sis opens up great opportunities toward further improving electrocatalytic activity. Moreover, this approach provides merits of facile, dynamical, continuous, reversible, and universal control. Despite fascinating achievements, these investigations are relatively scattered. The underneath mechanisms and principles Hydrogen fuel is considered as one of the most clean renewable resources, warranting it a primary alternative to fossil fuels for future energy supplies. Electrocatalytic water splitting is an eco-friendly technique for high-purity hydrogen production. However, the sluggish dynamics of its two halfreactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), are tough challenges impeding the practical application of this technology. In these years, external field-assisted HER and OER have attracted extensive research interests. Herein, the effects o...

show abstract

Regulating the Spin State of Fe^III by Atomically Anchoring on Ultrathin Titanium Dioxide for Efficient Oxygen Evolution Electrocatalysis

Cited by 275 publications

References 38 publications

Engineering Facets and Oxygen Vacancies over Hematite Single Crystal for Intensified Electrocatalytic H₂O₂ Production

Engineering Facets and Oxygen Vacancies over Hematite Single Crystal for Intensified Electrocatalytic H₂O₂ Production

Coupling Magnetic Single‐Crystal Co₂Mo₃O₈ with Ultrathin Nitrogen‐Rich Carbon Layer for Oxygen Evolution Reaction

Promoting Electrocatalytic Hydrogen Evolution Reaction and Oxygen Evolution Reaction by Fields: Effects of Electric Field, Magnetic Field, Strain, and Light

Contact Info

Product

Resources

About

Regulating the Spin State of FeIII by Atomically Anchoring on Ultrathin Titanium Dioxide for Efficient Oxygen Evolution Electrocatalysis

Cited by 275 publications

References 38 publications

Engineering Facets and Oxygen Vacancies over Hematite Single Crystal for Intensified Electrocatalytic H2O2 Production

Engineering Facets and Oxygen Vacancies over Hematite Single Crystal for Intensified Electrocatalytic H2O2 Production

Coupling Magnetic Single‐Crystal Co2Mo3O8 with Ultrathin Nitrogen‐Rich Carbon Layer for Oxygen Evolution Reaction

Promoting Electrocatalytic Hydrogen Evolution Reaction and Oxygen Evolution Reaction by Fields: Effects of Electric Field, Magnetic Field, Strain, and Light

Contact Info

Product

Resources

About

Regulating the Spin State of Fe^III by Atomically Anchoring on Ultrathin Titanium Dioxide for Efficient Oxygen Evolution Electrocatalysis

Engineering Facets and Oxygen Vacancies over Hematite Single Crystal for Intensified Electrocatalytic H₂O₂ Production

Engineering Facets and Oxygen Vacancies over Hematite Single Crystal for Intensified Electrocatalytic H₂O₂ Production

Coupling Magnetic Single‐Crystal Co₂Mo₃O₈ with Ultrathin Nitrogen‐Rich Carbon Layer for Oxygen Evolution Reaction