Abstract
Graphane, graphone, and hydrogenated graphene (HG) have been extensively studied in recent years due to their interesting properties and potential use in commercial and industrial applications. The present study reports investigation of hydrogenated graphene/TiO2-x (HGT) nanocomposites as photocatalysts for H2 and O2 production from water without the assistance of a noble metal cocatalyst. By combination of several techniques, the morphologies, bulk/atomic structure, and electronic properties of all the powders were exhaustively interrogated. Hydrogenation treatment efficiently reduces TiO2 nanoparticles, while the graphene oxide sheets undergo the topotactic transformation from a graphene-like structure to a mixture of graphitic and turbostratic carbon (amorphous/disordered) upon altering the calcination atmosphere from a mildly reducing to a H2-abundant environment. Remarkably, the hydrogenated graphene-TiO2-x composite that results upon H2-rich reduction exhibits the highest photocatalytic H2 evolution performance equivalent to low loading of Pt (μ0.12 wt %), whereas the addition of HG suppresses the O2 production. We propose that such an enhancement can be attributed to a combination of factors including the introduction of oxygen vacancies and Ti3+ states, retarding the recombination of charge carriers, and thus, facilitating the charge transfer from TiO2-x to the carbonaceous sheet.
| Original language | English |
|---|---|
| Pages (from-to) | 6282-6296 |
| Number of pages | 15 |
| Journal | Chemistry of Materials |
| Volume | 27 |
| Issue number | 18 |
| DOIs | |
| Publication status | Published - Sep 22 2015 |
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ASJC Scopus subject areas
- Materials Chemistry
- Chemical Engineering(all)
- Chemistry(all)
Cite this
Striving Toward Noble-Metal-Free Photocatalytic Water Splitting : The Hydrogenated-Graphene-TiO2 Prototype. / Nguyen-Phan, Thuy Duong; Luo, Si; Liu, Zongyuan; Gamalski, Andrew D.; Tao, Jing; Xu, Wenqian; Stach, Eric A.; Polyansky, Dmitry; Senanayake, Sanjaya D.; Fujita, Etsuko; Rodriguez, José A.
In: Chemistry of Materials, Vol. 27, No. 18, 22.09.2015, p. 6282-6296.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Striving Toward Noble-Metal-Free Photocatalytic Water Splitting
T2 - The Hydrogenated-Graphene-TiO2 Prototype
AU - Nguyen-Phan, Thuy Duong
AU - Luo, Si
AU - Liu, Zongyuan
AU - Gamalski, Andrew D.
AU - Tao, Jing
AU - Xu, Wenqian
AU - Stach, Eric A.
AU - Polyansky, Dmitry
AU - Senanayake, Sanjaya D.
AU - Fujita, Etsuko
AU - Rodriguez, José A.
PY - 2015/9/22
Y1 - 2015/9/22
N2 - Graphane, graphone, and hydrogenated graphene (HG) have been extensively studied in recent years due to their interesting properties and potential use in commercial and industrial applications. The present study reports investigation of hydrogenated graphene/TiO2-x (HGT) nanocomposites as photocatalysts for H2 and O2 production from water without the assistance of a noble metal cocatalyst. By combination of several techniques, the morphologies, bulk/atomic structure, and electronic properties of all the powders were exhaustively interrogated. Hydrogenation treatment efficiently reduces TiO2 nanoparticles, while the graphene oxide sheets undergo the topotactic transformation from a graphene-like structure to a mixture of graphitic and turbostratic carbon (amorphous/disordered) upon altering the calcination atmosphere from a mildly reducing to a H2-abundant environment. Remarkably, the hydrogenated graphene-TiO2-x composite that results upon H2-rich reduction exhibits the highest photocatalytic H2 evolution performance equivalent to low loading of Pt (μ0.12 wt %), whereas the addition of HG suppresses the O2 production. We propose that such an enhancement can be attributed to a combination of factors including the introduction of oxygen vacancies and Ti3+ states, retarding the recombination of charge carriers, and thus, facilitating the charge transfer from TiO2-x to the carbonaceous sheet.
AB - Graphane, graphone, and hydrogenated graphene (HG) have been extensively studied in recent years due to their interesting properties and potential use in commercial and industrial applications. The present study reports investigation of hydrogenated graphene/TiO2-x (HGT) nanocomposites as photocatalysts for H2 and O2 production from water without the assistance of a noble metal cocatalyst. By combination of several techniques, the morphologies, bulk/atomic structure, and electronic properties of all the powders were exhaustively interrogated. Hydrogenation treatment efficiently reduces TiO2 nanoparticles, while the graphene oxide sheets undergo the topotactic transformation from a graphene-like structure to a mixture of graphitic and turbostratic carbon (amorphous/disordered) upon altering the calcination atmosphere from a mildly reducing to a H2-abundant environment. Remarkably, the hydrogenated graphene-TiO2-x composite that results upon H2-rich reduction exhibits the highest photocatalytic H2 evolution performance equivalent to low loading of Pt (μ0.12 wt %), whereas the addition of HG suppresses the O2 production. We propose that such an enhancement can be attributed to a combination of factors including the introduction of oxygen vacancies and Ti3+ states, retarding the recombination of charge carriers, and thus, facilitating the charge transfer from TiO2-x to the carbonaceous sheet.
UR - http://www.scopus.com/inward/record.url?scp=84942133537&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84942133537&partnerID=8YFLogxK
U2 - 10.1021/acs.chemmater.5b02131
DO - 10.1021/acs.chemmater.5b02131
M3 - Article
AN - SCOPUS:84942133537
VL - 27
SP - 6282
EP - 6296
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 18
ER -