scholarly journals Interfacial Chemical Bond and Internal Electric Field Modulated Z-Scheme Vs-ZnIn2S4/MoSe2 Photocatalyst for Efficient Hydrogen Evolution

2021 ◽  
Author(s):  
Xuehua Wang ◽  
Xianghu Wang ◽  
Jianfeng Huang ◽  
Shaoxiang Li ◽  
Alan meng ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electric Field ◽  
Hydrogen Evolution ◽  
Photocatalytic Performance ◽  
Monochromatic Light ◽  
Spin Trapping ◽  
Atomic Level ◽  
Internal Electric Field ◽  
Apparent Quantum Yield ◽  
Interface Control

Abstract Construction of Z-scheme heterostructure is of momentous significance for realizing efficient photocatalytic water splitting. However, the consciously modulate of Z-scheme charge transfer is still a great challenge. Herein, interfacial Mo-S bond and internal electric field modulated Z-Scheme heterostructure composed by sulfur vacancies-rich ZnIn2S4 (Vs-ZIS) and MoSe2 was rationally fabricated for efficient photocatalytic hydrogen evolution. Systematic investigations reveal that Mo-S bond and internal electric field induce the Z-scheme charge transfer mechanism as confirmed by the SPS and DMPO spin-trapping EPR spectra. Under the intense synergy among the Mo-S bond, internal electric field and S-vacancies, the optimized photocatalyst exhibits ultrahigh hydrogen evolution rate of 63.21 mmol∙g-1·h-1 with an apparent quantum yield of 76.48% at 420 nm monochromatic light, which is about 18.8-fold of the pristine ZIS. This work affords a new inspiration on consciously modulating Z-scheme charge transfer by atomic-level interface control and internal electric field to signally promote the photocatalytic performance.

scholarly journals Interfacial chemical bond and internal electric field modulated Z-scheme Sv-ZnIn2S4/MoSe2 photocatalyst for efficient hydrogen evolution

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xuehua Wang ◽  
Xianghu Wang ◽  
Jianfeng Huang ◽  
Shaoxiang Li ◽  
Alan Meng ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electric Field ◽  
Hydrogen Evolution ◽  
Density Functional ◽  
Monochromatic Light ◽  
Density Functional Theory Calculations ◽  
Internal Electric Field ◽  
Apparent Quantum Yield ◽  
Paramagnetic Resonance ◽  
High Hydrogen

AbstractConstruction of Z-scheme heterostructure is of great significance for realizing efficient photocatalytic water splitting. However, the conscious modulation of Z-scheme charge transfer is still a great challenge. Herein, interfacial Mo-S bond and internal electric field modulated Z-scheme heterostructure composed by sulfur vacancies-rich ZnIn2S4 and MoSe2 was rationally fabricated for efficient photocatalytic hydrogen evolution. Systematic investigations reveal that Mo-S bond and internal electric field induce the Z-scheme charge transfer mechanism as confirmed by the surface photovoltage spectra, DMPO spin-trapping electron paramagnetic resonance spectra and density functional theory calculations. Under the intense synergy among the Mo-S bond, internal electric field and S-vacancies, the optimized photocatalyst exhibits high hydrogen evolution rate of 63.21 mmol∙g−1·h−1 with an apparent quantum yield of 76.48% at 420 nm monochromatic light, which is about 18.8-fold of the pristine ZIS. This work affords a useful inspiration on consciously modulating Z-scheme charge transfer by atomic-level interface control and internal electric field to signally promote the photocatalytic performance.

scholarly journals Conjugated Polymer Donor-Molecular Acceptor Nanohybrids for Photocatalytic Hydrogen Evolution

2019 ◽  
Author(s):  
Haofan Yang ◽  
Xiaobo Li ◽  
Reiner Sebastian Sprick ◽  
Andrew I. Cooper
Keyword(s):  
Photocatalytic Activity ◽  
Charge Transfer ◽  
Conjugated Polymers ◽  
Hydrogen Evolution ◽  
Conjugated Polymer ◽  
Apparent Quantum Yield ◽  
High Hydrogen ◽  
Photocatalytic Hydrogen Evolution ◽  
Efficient Charge ◽  
Donor Acceptor

A library of 237 organic binary/ternary nanohybrids consisting of conjugated polymers donors and both fullerene and non-fullerene molecular acceptors was prepared and screened for sacrificial photocatalytic hydrogen evolution. These donor-acceptor nanohybrids (DANHs) showed significantly enhanced hydrogen evolution rates compared with the parent donor or acceptor compounds. DANHs of <a></a><a>a polycarbazole</a>-based donor combined with a methanofullerene acceptor (PCDTBT/PC<sub>60</sub>BM) showed a high hydrogen evolution rate of 105.2 mmol g<sup>-1</sup> h<sup>-1</sup> under visible light (λ > 420 nm). This DANH photocatalyst produced 5.9 times more hydrogen than a sulfone-containing polymer (P10) under the same conditions, which is one of the most efficient organic photocatalysts reported so far. An apparent quantum yield of hydrogen evolution of 3.0 % at 595 nm was measured for this DANH. The photocatalytic activity of the DANHs, which in optimized cases reached 179.0 mmol g<sup>-1</sup> h<sup>-1</sup>, is attributed to efficient charge transfer at the polymer donor/molecular acceptor interface. We also show that ternary donor<sub>A</sub>-donor<sub>B</sub>-acceptor nanohybrids can give higher activities than binary donor-acceptor hybrids in some cases.

scholarly journals Conjugated Polymer Donor-Molecular Acceptor Nanohybrids for Photocatalytic Hydrogen Evolution

2019 ◽  
Author(s):  
Haofan Yang ◽  
Xiaobo Li ◽  
Reiner Sebastian Sprick ◽  
Andrew I. Cooper
Keyword(s):  
Photocatalytic Activity ◽  
Charge Transfer ◽  
Conjugated Polymers ◽  
Hydrogen Evolution ◽  
Conjugated Polymer ◽  
Apparent Quantum Yield ◽  
High Hydrogen ◽  
Photocatalytic Hydrogen Evolution ◽  
Efficient Charge ◽  
Donor Acceptor

A library of 237 organic binary/ternary nanohybrids consisting of conjugated polymers donors and both fullerene and non-fullerene molecular acceptors was prepared and screened for sacrificial photocatalytic hydrogen evolution. These donor-acceptor nanohybrids (DANHs) showed significantly enhanced hydrogen evolution rates compared with the parent donor or acceptor compounds. DANHs of <a></a><a>a polycarbazole</a>-based donor combined with a methanofullerene acceptor (PCDTBT/PC<sub>60</sub>BM) showed a high hydrogen evolution rate of 105.2 mmol g<sup>-1</sup> h<sup>-1</sup> under visible light (λ > 420 nm). This DANH photocatalyst produced 5.9 times more hydrogen than a sulfone-containing polymer (P10) under the same conditions, which is one of the most efficient organic photocatalysts reported so far. An apparent quantum yield of hydrogen evolution of 3.0 % at 595 nm was measured for this DANH. The photocatalytic activity of the DANHs, which in optimized cases reached 179.0 mmol g<sup>-1</sup> h<sup>-1</sup>, is attributed to efficient charge transfer at the polymer donor/molecular acceptor interface. We also show that ternary donor<sub>A</sub>-donor<sub>B</sub>-acceptor nanohybrids can give higher activities than binary donor-acceptor hybrids in some cases.

scholarly journals Enhancement of photocatalytic H2 evolution of eosin Y-sensitized reduced graphene oxide through a simple photoreaction

2014 ◽  
Vol 5 ◽  
pp. 801-811 ◽  
Author(s):  
Weiying Zhang ◽  
Yuexiang Li ◽  
Shaoqin Peng ◽  
Xiang Cai
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Irradiation Time ◽  
Monochromatic Light ◽  
Light Irradiation ◽  
Xenon Lamp ◽  
Eosin Y ◽  
Apparent Quantum Yield ◽  
Reduced Graphene

A graphene oxide (GO) solution was irradiated by a Xenon lamp to form reduced graphene oxide (RGO). After irradiation, the epoxy, the carbonyl and the hydroxy groups are gradually removed from GO, resulting in an increase of sp2 π-conjugated domains and defect carbons with holes for the formed RGO. The RGO conductivity increases due to the restoration of sp2 π-conjugated domains. The photocatalytic activity of EY-RGO/Pt for hydrogen evolution was investigated with eosin Y (EY) as a sensitizer of the RGO and Pt as a co-catalyst. When the irradiation time is increased from 0 to 24 h the activity rises, and then reaches a plateau. Under optimum conditions (pH 10.0, 5.0 × 10−4 mol L−1 EY, 10 μg mL−1 RGO), the maximal apparent quantum yield (AQY) of EY-RGO24/Pt for hydrogen evolution rises up to 12.9% under visible light irradiation (λ ≥ 420 nm), and 23.4% under monochromatic light irradiation at 520 nm. Fluorescence spectra and transient absorption decay spectra of the EY-sensitized RGO confirm that the electron transfer ability of RGO increases with increasing irradiation time. The adsorption quantity of EY on the surface of RGO enhances, too. The two factors ultimately result in an enhancement of the photocatalytic hydrogen evolution over EY-RGO/Pt with increasing irradiation time. A possible mechanism is discussed.

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