Strongly coupled CdS/graphene quantum dots nanohybrids for highly efficient photocatalytic hydrogen evolution: unraveling the essential roles of graphene quantum dots

Handle URI:
http://hdl.handle.net/10754/623720
Title:
Strongly coupled CdS/graphene quantum dots nanohybrids for highly efficient photocatalytic hydrogen evolution: unraveling the essential roles of graphene quantum dots
Authors:
Lei, Yonggang; Yang, Cheng; Hou, Jianhua; Wang, Fang; Min, Shixiong; Ma, Xiaohua; Jin, Zhiliang; Xu, Jing; Lu, Gongxuan; Huang, Kuo-Wei ( 0000-0003-1900-2658 )
Abstract:
It have been recognized that the coupling of graphene quantum dots (GQDs) with semiconductor photocatalysts endow the resulting nanocomposites with enhanced photocatalytic performances, however, the essential roles of GQDs have not been clearly revealed yet. Herein, we report that a high efficiency of the photocatalytic H2 evolution was achieved using strongly coupled nanohybrids of CdS with GQDs (CdS/GQDs) as visible-light-driven photocatalysts. CdS/GQDs nanohybrids were synthesized by a facile hydrothermal method in which the crystallization of CdS precursor and coupling of GQDs could be accomplished in one-step. GQDs are firmly decorated on the surface of CdS nanoparticles, forming “dot-on-particle” heterodimer structures. GQDs have no significant influence on the crystallite structure of CdS but render the nanohybrids with strong light absorption at the wavelength beyond the band edge of CdS. Under visible light irradiation (≥420nm), CdS/GQDs nanohybrids reach the highest H2 production rate of 95.4μmol·h−1, about 2.7 times higher than that of pure CdS nanoparticles, at GQDs content of 1.0wt %, and the apparent quantum efficiency (AQE) was determined to be 4.2% at 420nm. Incident light-wavelength dependent experiments reveal that the light absorption of CdS dominated the performance of nanohybrids, and the excess light absorption coming from GQDs hardly contributes to the observed higher activity. Photocurrent response, steady-state and time-resolved PL, and EIS measurements suggest that the high activity of CdS/GQDs is attributed predominantly to the graphene-like nature of GQDs, which can act as an efficient electron acceptor to induce an efficient charge separation. This work clearly reveals that GQDs mainly played a role of electron acceptor instead of a photosensitizer in enhancing the photocatalytic H2 evolution performances of CdS/GQDs nanohybrids, which offers a new insight to understand the essential roles of GQDs in semiconductor/GQDs nanohybrids for efficient solar energy conversion applications.
KAUST Department:
KAUST Catalysis Center (KCC)
Citation:
Lei Y, Yang C, Hou J, Wang F, Min S, et al. (2017) Strongly coupled CdS/graphene quantum dots nanohybrids for highly efficient photocatalytic hydrogen evolution: unraveling the essential roles of graphene quantum dots. Applied Catalysis B: Environmental. Available: http://dx.doi.org/10.1016/j.apcatb.2017.05.063.
Publisher:
Elsevier BV
Journal:
Applied Catalysis B: Environmental
Issue Date:
23-May-2017
DOI:
10.1016/j.apcatb.2017.05.063
Type:
Article
ISSN:
0926-3373
Sponsors:
This work is supported by the National Science Foundation of China (21463001, 41663012), Graduate student innovation project (YCX1778), the Natural Science Foundation of Ningxia Hui Autonomous Region (NZ15102), the Scientific Research Projects of the State Ethnic Affairs Commission (2066204), and the Cultivation Project of National Natural Science Foundation of China (2014QZP04).
Additional Links:
http://www.sciencedirect.com/science/article/pii/S0926337317304824
Appears in Collections:
Articles; KAUST Catalysis Center (KCC)

Full metadata record

DC FieldValue Language
dc.contributor.authorLei, Yonggangen
dc.contributor.authorYang, Chengen
dc.contributor.authorHou, Jianhuaen
dc.contributor.authorWang, Fangen
dc.contributor.authorMin, Shixiongen
dc.contributor.authorMa, Xiaohuaen
dc.contributor.authorJin, Zhiliangen
dc.contributor.authorXu, Jingen
dc.contributor.authorLu, Gongxuanen
dc.contributor.authorHuang, Kuo-Weien
dc.date.accessioned2017-05-25T10:55:14Z-
dc.date.available2017-05-25T10:55:14Z-
dc.date.issued2017-05-23en
dc.identifier.citationLei Y, Yang C, Hou J, Wang F, Min S, et al. (2017) Strongly coupled CdS/graphene quantum dots nanohybrids for highly efficient photocatalytic hydrogen evolution: unraveling the essential roles of graphene quantum dots. Applied Catalysis B: Environmental. Available: http://dx.doi.org/10.1016/j.apcatb.2017.05.063.en
dc.identifier.issn0926-3373en
dc.identifier.doi10.1016/j.apcatb.2017.05.063en
dc.identifier.urihttp://hdl.handle.net/10754/623720-
dc.description.abstractIt have been recognized that the coupling of graphene quantum dots (GQDs) with semiconductor photocatalysts endow the resulting nanocomposites with enhanced photocatalytic performances, however, the essential roles of GQDs have not been clearly revealed yet. Herein, we report that a high efficiency of the photocatalytic H2 evolution was achieved using strongly coupled nanohybrids of CdS with GQDs (CdS/GQDs) as visible-light-driven photocatalysts. CdS/GQDs nanohybrids were synthesized by a facile hydrothermal method in which the crystallization of CdS precursor and coupling of GQDs could be accomplished in one-step. GQDs are firmly decorated on the surface of CdS nanoparticles, forming “dot-on-particle” heterodimer structures. GQDs have no significant influence on the crystallite structure of CdS but render the nanohybrids with strong light absorption at the wavelength beyond the band edge of CdS. Under visible light irradiation (≥420nm), CdS/GQDs nanohybrids reach the highest H2 production rate of 95.4μmol·h−1, about 2.7 times higher than that of pure CdS nanoparticles, at GQDs content of 1.0wt %, and the apparent quantum efficiency (AQE) was determined to be 4.2% at 420nm. Incident light-wavelength dependent experiments reveal that the light absorption of CdS dominated the performance of nanohybrids, and the excess light absorption coming from GQDs hardly contributes to the observed higher activity. Photocurrent response, steady-state and time-resolved PL, and EIS measurements suggest that the high activity of CdS/GQDs is attributed predominantly to the graphene-like nature of GQDs, which can act as an efficient electron acceptor to induce an efficient charge separation. This work clearly reveals that GQDs mainly played a role of electron acceptor instead of a photosensitizer in enhancing the photocatalytic H2 evolution performances of CdS/GQDs nanohybrids, which offers a new insight to understand the essential roles of GQDs in semiconductor/GQDs nanohybrids for efficient solar energy conversion applications.en
dc.description.sponsorshipThis work is supported by the National Science Foundation of China (21463001, 41663012), Graduate student innovation project (YCX1778), the Natural Science Foundation of Ningxia Hui Autonomous Region (NZ15102), the Scientific Research Projects of the State Ethnic Affairs Commission (2066204), and the Cultivation Project of National Natural Science Foundation of China (2014QZP04).en
dc.publisherElsevier BVen
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S0926337317304824en
dc.rightsNOTICE: this is the author’s version of a work that was accepted for publication in Applied Catalysis B: Environmental. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Applied Catalysis B: Environmental, [, , (2017-05-23)] DOI: 10.1016/j.apcatb.2017.05.063 . © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectGraphene quantum dotsen
dc.subjectCdSen
dc.subjectnanohybridsen
dc.subjectphotocatalysisen
dc.subjectH2 evolutionen
dc.titleStrongly coupled CdS/graphene quantum dots nanohybrids for highly efficient photocatalytic hydrogen evolution: unraveling the essential roles of graphene quantum dotsen
dc.typeArticleen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.identifier.journalApplied Catalysis B: Environmentalen
dc.eprint.versionPost-printen
dc.contributor.institutionSchool of Chemistry and Chemical Engineering, Beifang University of Nationalities, Yinchuan 750021, Ningxia Province, Chinaen
dc.contributor.institutionState Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, Chinaen
kaust.authorHuang, Kuo-Weien
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