scholarly journals Turbulence Enhanced Ferroelectric-Nanocrystal-Based Photocatalysis in Urchin-like TiO2/BaTiO3 Microspheres for Hydrogen Evolution

2021 ◽  
Author(s):  
Haidong Li ◽  
Yanyan Song ◽  
Jiyun Zhang ◽  
Jiating He

The application of built-in electric field due to piezoelectric potential is one of the most efficient approaches for photo-induced charge transport and separation. However, the efficiency of converting mechanical energy...

2018 ◽  
Vol 52 ◽  
pp. 288-294 ◽  
Author(s):  
Motiur Rahman Khan ◽  
K.S.R. Koteswara Rao ◽  
R. Menon

2019 ◽  
Author(s):  
Yan Wang ◽  
Sagar Udyavara ◽  
Matthew Neurock ◽  
C. Daniel Frisbie

<div> <div> <div> <p> </p><div> <div> <div> <p>Electrocatalytic activity for hydrogen evolution at monolayer MoS2 electrodes can be enhanced by the application of an electric field normal to the electrode plane. The electric field is produced by a gate electrode lying underneath the MoS2 and separated from it by a dielectric. Application of a voltage to the back-side gate electrode while sweeping the MoS2 electrochemical potential in a conventional manner in 0.5 M H2SO4 results in up to a 140-mV reduction in overpotential for hydrogen evolution at current densities of 50 mA/cm2. Tafel analysis indicates that the exchange current density is correspondingly improved by a factor of 4 to 0.1 mA/cm2 as gate voltage is increased. Density functional theory calculations support a mechanism in which the higher hydrogen evolution activity is caused by gate-induced electronic charge on Mo metal centers adjacent the S vacancies (the active sites), leading to enhanced Mo-H bond strengths. Overall, our findings indicate that the back-gated working electrode architecture is a convenient and versatile platform for investigating the connection between tunable electronic charge at active sites and overpotential for electrocatalytic processes on ultrathin electrode materials.</p></div></div></div><br><p></p></div></div></div>


2021 ◽  
Vol 14 (3) ◽  
pp. 1594-1601
Author(s):  
Adeela Nairan ◽  
Caiwu Liang ◽  
Sum-Wai Chiang ◽  
Yi Wu ◽  
Peichao Zou ◽  
...  

A superior HER activity was achieved by strong localized electric field induced selected H+ accumulation on the cathode.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Chunzheng Lv ◽  
Lirong He ◽  
Jiahong Tang ◽  
Feng Yang ◽  
Chuhong Zhang

AbstractAs an important photoconductive hybrid material, perylene/ZnO has attracted tremendous attention for photovoltaic-related applications, but generally faces a great challenge to design molecular level dispersed perylenes/ZnO nanohybrids due to easy phase separation between perylenes and ZnO nanocrystals. In this work, we reported an in-situ reaction method to prepare molecular level dispersed H-aggregates of perylene bisimide/ZnO nanorod hybrids. Surface photovoltage and electric field-induced surface photovoltage spectrum show that the photovoltage intensities of nanorod hybrids increased dramatically for 100 times compared with that of pristine perylene bisimide. The enhancement of photovoltage intensities resulting from two aspects: (1) the photo-generated electrons transfer from perylene bisimide to ZnO nanorod due to the electric field formed on the interface of perylene bisimide/ZnO; (2) the H-aggregates of perylene bisimide in ZnO nanorod composites, which is beneficial for photo-generated charge separation and transportation. The introduction of ordered self-assembly thiol-functionalized perylene-3,4,9,10-tetracarboxylic diimide (T-PTCDI)/ ZnO nanorod composites induces a significant improvement in incident photo-to-electron conversion efficiency. This work provides a novel mentality to boost photo-induced charge transfer efficiency, which brings new inspiration for the preparation of the highly efficient solar cell.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xuehua Wang ◽  
Xianghu Wang ◽  
Jianfeng Huang ◽  
Shaoxiang Li ◽  
Alan Meng ◽  
...  

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.


2017 ◽  
Vol 19 (46) ◽  
pp. 31429-31435 ◽  
Author(s):  
Kun-Che Kao ◽  
Yoshinori Kuroiwa ◽  
Hiroyasu Nishi ◽  
Tetsu Tatsuma

Plasmonic Au nanoparticles inject electrons into TiO2 and reduce water to hydrogen at a Pt cathode. Positive charges left in the Au nanoparticles are extracted by NiO and used for methanol oxidation.


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