Shape and size effects on photocatalytic hydrogen production via Pd/C3N4 photocatalysts under visible light

2020 ◽  
Vol 10 (16) ◽  
pp. 5438-5442 ◽  
Author(s):  
Guoliang Gao ◽  
Xingxing Niu ◽  
Beibei Xu ◽  
Xue Lu Wang ◽  
Ye-Feng Yao
Keyword(s):  
Hydrogen Production ◽  
Visible Light ◽  
Size Effects ◽  
Oxidation Reaction ◽  
Pd Nanoparticles ◽  
Photocatalytic Reaction ◽  
Photocatalytic Hydrogen Production ◽  
Reduction And Oxidation ◽  
Shape And Size

Through a combination of operando NMR and GC, the effects of Pd nanoparticles with different crystal planes and sizes on the reduction and oxidation reaction parts of the photocatalytic reaction were studied in detail.

scholarly journals Roles of cocatalysts in semiconductor-based photocatalytic hydrogen production

2013 ◽  
Vol 371 (1996) ◽  
pp. 20110430 ◽  
Author(s):  
Jinhui Yang ◽  
Hongjian Yan ◽  
Xu Zong ◽  
Fuyu Wen ◽  
Meiying Liu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Composite Material ◽  
Photocatalytic Activity ◽  
Hydrogen Production ◽  
Charge Separation ◽  
Reaction Rate ◽  
Photocatalytic Performance ◽  
Photocatalytic Reaction ◽  
Photocatalytic Hydrogen Production ◽  
Reduction And Oxidation

A photocatalyst is defined as a functional composite material with three components: photo-harvester (e.g. semiconductor), reduction cocatalyst (e.g. for hydrogen evolution) and oxidation cocatalyst (e.g. for oxidation evolution from water). Loading cocatalysts on semiconductors is proved to be an effective approach to promote the charge separation and transfer, suppress the charge recombination and enhance the photocatalytic activity. Furthermore, the photocatalytic performance can be significantly improved by loading dual cocatalysts for reduction and oxidation, which could lower the activation energy barriers, respectively, for the two half reactions. A quantum efficiency (QE) as high as 93 per cent at 420 nm for H 2 production has been achieved for Pt–PdS/CdS, where Pt and PdS, respectively, act as reduction and oxidation cocatalysts and CdS as a photo-harvester. The dual cocatalysts work synergistically and enhance the photocatalytic reaction rate, which is determined by the slower one (either reduction or oxidation). This work demonstrates that the cocatalysts, especially the dual cocatalysts for reduction and oxidation, are crucial and even absolutely necessary for achieving high QEs in photocatalytic hydrogen production, as well as in photocatalytic water splitting.

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