Functionalization of graphene materials by heteroatom-doping for energy conversion and storage

Hu, Chuangang; Liu, Dong; Xiao, Ying; Dai, Liming

doi:10.1016/j.pnsc.2018.02.001

Cited by 158 publications

(73 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, silver has been applied as a hole‐extraction material in inverted polymer solar cells (IPSCs) owing to its electronic properties and its work function. In an IPSC, the WF should be sufficiently high to allow for the build‐up of the electric field within the active component in the cell to maximize the extraction of holes from the active material …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Affecting an Ultra‐High Work Function of Silver

Armstrong

Cong

et al. 2020

Angew Chem Int Ed

View full text Add to dashboard Cite

An ultra‐high increase in the WF of silver, from 4.26 to 7.42 eV, that is, an increase of up to circa 3.1 eV is reported. This is the highest WF increase on record for metals and is supported by recent computational studies which predict the potential ability to affect an increase of the WF of metals by more than 4 eV. We achieved the ultra‐high increase by a new approach: Rather than using the common method of 2D adsorption of polar molecules layers on the metal surface, WF modifying components, l‐cysteine and Zn(OH)2, were incorporated within the metal, resulting in a 3D architecture. Detailed material characterization by a large array of analytical methods was carried out, the combination of which points to a WF enhancement mechanism which is based on directly affecting the charge transfer ability of the metal separately by cysteine and hydrolyzed zinc(II), and synergistically by the combination of the two through the known Zn‐cysteine finger redox trap effect.

show abstract

Section: Resultsmentioning

confidence: 99%

“…In an IPSC,t he WF should be sufficiently high to allow for the build-up of the electric field within the active component in the cell to maximize the extraction of holes from the active material. [9,51]…”

Section: Resultsmentioning

confidence: 99%

Affecting an Ultra‐High Work Function of Silver

Armstrong

Cong

et al. 2020

Angew Chem Int Ed

View full text Add to dashboard Cite

show abstract

“…However, graphene is constructed of sp 2 -bonded carbon atoms via hybridization of s, p x , and p y atomic orbitals, resulting in a zero-band gap semiconductor with the conduction and valence bands. The lack of intrinsic bandgap muchly limits the applications of pristine graphene in the areas of energy storage, electrocatalysis, and nanoelectronics [73]. Fortunately, chemical doping with foreign atoms has been demonstrated to be an effective method to tailor the electronic and electrochemical properties of graphene by changing the electronic density within the graphene sheet, thus opening the bandgap in graphene, and extending its applications [74,75].…”

Section: Heteroatom-doped 3d Graphene For Orrmentioning

confidence: 99%

Three-Dimensional Heteroatom-Doped Nanocarbon for Metal-Free Oxygen Reduction Electrocatalysis: A Review

Xiong

Fan

et al. 2018

Catalysts

View full text Add to dashboard Cite

Abstract:The oxygen reduction reaction (ORR) at the cathode is a fundamental process and functions a pivotal role in fuel cells and metal-air batteries. However, the electrochemical performance of these technologies has been still challenged by the high cost, scarcity, and insufficient durability of the traditional Pt-based ORR electrocatalysts. Heteroatom-doped nanocarbon electrocatalysts with competitive activity, enhanced durability, and acceptable cost, have recently attracted increasing interest and hold great promise as substitute for precious-metal catalysts (e.g., Pt and Pt-based materials). More importantly, three-dimensional (3D) porous architecture appears to be necessary for achieving high catalytic ORR activity by providing high specific surface areas with more exposed active sites and large pore volumes for efficient mass transport of reactants to the electrocatalysts. In this review, recent progress on the design, fabrication, and performance of 3D heteroatom-doped nanocarbon catalysts is summarized, aiming to elucidate the effects of heteroatom doping and 3D structure on the ORR performance of nanocarbon catalysts, thus promoting the design of highly active nanocarbon-based ORR electrocatalysts.

show abstract

“…The graphene edge and/or basal plane chemical activation may be via covalent or noncovalent interaction. These impart solubility, film forming capability, and enhanced chemical reactivity that modulate the properties for multifunctional applications . For instance, Ju et al recently reported edge‐selective doping as a way of preserving the pristine graphene basal plane and further showed that edge‐selenated graphene nanoplatelets are robust metal‐free catalysts for the iodine redox reaction in the CE of DSSCs.…”

Section: Mechanistic Issues In Dsscsmentioning

confidence: 99%

“…These impart solubility, film forming capability, and enhanced chemical reactivity that modulate the properties for multifunctional applications. 39,40 For instance, Ju et al 41 recently reported edgeselective doping as a way of preserving the pristine graphene basal plane and further showed that edgeselenated graphene nanoplatelets are robust metal-free catalysts for the iodine redox reaction in the CE of DSSCs. The value of the charge transfer resistance, R ct , at the CEelectrolyte interface indicates the effectiveness of the CE in regenerating the iodine species in the electrolyte.…”

Section: Mechanistic Issues In Dsscsmentioning

confidence: 99%

Heteroatom-doped graphene and its application as a counter electrode in dye-sensitized solar cells

2018

View full text Add to dashboard Cite

Summary The most frequently used counter electrode (CE) in dye‐sensitized solar cells (DSSCs) is platinum on fluorine‐doped tin oxide glass. This electrode has excellent electrical conductivity, chemical stability, and high electrocatalytic affinity for the reduction of triiodide. However, the high cost of metallic platinum and the poor electrochemical stability pose a major drawback in the commercial production. This has necessitated a search for a non‐precious metal and metal‐free electrocatalyst that demonstrates better catalytic activity and longer electrochemical stability for practical use in DSSCs. Graphene has been at the centre of attention due to its excellent optoelectronic properties. However, a defect‐free graphene sheet is not suitable as a CE in DSSCs, because of its neutral polarity which often restricts efficient charge transfer at the graphene/liquid interface, irrespective of the high in‐plane charge mobility. Hence, heteroatom‐doped graphene‐based CEs are being developed with the aim to balance electrical conductivity for efficient charge transfer and charge polarization for enhanced reduction activity of redox couples simultaneously. The elements commonly used in chemical doping of graphene are nitrogen, oxygen, boron, sulfur, and phosphorus. Halogens have also recently shown great promise. It has been demonstrated that edge‐selective heteroatom‐doping of graphene imparts both efficient in‐plane charge transfers and polarity, thereby enhancing electrocatalytic activity. Thus, heteroatom‐doped graphene serves as a good material to replace conventional electrodes and enhance power conversion efficiency in DSSCs. The focus is to reduce the cost of DSSCs. This review explores the performance of DSSCs, factors that influence the power conversion efficiency, and various physicochemical properties of graphene. It further outlines current progress on the synthetic approaches for chemical doping (substitutional and surface transfer doping) of graphene and graphene oxide with different heteroatoms in order to fine‐tune the electronic properties. The use of heteroatom‐doped graphene as a CE in DSSCs and how it improves the photovoltaic performance of cells is discussed.

show abstract

Functionalization of graphene materials by heteroatom-doping for energy conversion and storage

Cited by 158 publications

References 82 publications

Affecting an Ultra‐High Work Function of Silver

Affecting an Ultra‐High Work Function of Silver

Three-Dimensional Heteroatom-Doped Nanocarbon for Metal-Free Oxygen Reduction Electrocatalysis: A Review

Heteroatom-doped graphene and its application as a counter electrode in dye-sensitized solar cells

Contact Info

Product

Resources

About