scholarly journals Effective Photocatalytic Hydrogen Evolution Using Covalent Triazine Framework-Derived Carbon Nitride Nanofiber Containing Carbon Vacancies for Visible-Light-Driven

2021 ◽  
Vol 11 (16) ◽  
pp. 7222
Author(s):  
Liangjing Zhang ◽  
Aiwu Wang ◽  
Mei Zhang ◽  
Zhengyuan Jin ◽  
Huan Yi ◽  
...  

In this study, a novel fibrous carbon nitride (FCN) was prepared from laminated covalent triazine framework (CTF) via pyrolysis, using functionalized 2,5-thiophenedicarboxylic acid and melamine as the precursors. A carbon vacancy was produced by two-step calcination in argon and air atmospheres. These carbon vacancies further exposed the edges and diffusion channels of the FCN nanofibers, which accelerated photogenerated charge transfer and provided more active sites. The FCN was characterized using various techniques and used for H2 evolution under visible-light irradiation. The as-synthesized FCN exhibited excellent stability, and its photocatalytic activity for H2 evolution under visible-light irradiation was 66 times higher than that of bare C3N4 (BCN), attaining a maximum H2 evolution rate of 102.63 μmol in 6 h. The FCN remained stable following visible-light irradiation at the end of 10 cycles. The FCN benefited from the absorption of solar energy and a large number of active sites. These advantages facilitated the efficient separation of photoexcited electron-hole pairs to hinder charge recombination. This work generates new insights into the preparation of highly effective FCN photocatalysts that may be put to various applications, especially in the fields of energy and environment.

Author(s):  
Shu Chin Lee ◽  
Wee Shern Chew ◽  
Hendrik O. Lintang ◽  
Leny Yuliati

Carbon nitride is a material of interest for photocatalytic reactions due to its catalytic and visible light absorption properties. However, the photocatalytic activity is still low. Hence, modifications must be carried out to improve the photocatalytic activity of carbon nitride. In this work, a series of gallium oxide/carbon nitride composites with various gallium to carbon ratios (Ga/C = 1-50 mol%) was prepared by impregnation method for removal of cyclohexane under visible light irradiation for the first time. The successful preparation of gallium oxide/carbon nitride composites was supported by several characterization techniques. X-ray diffraction (XRD) patterns and diffuse reflectance UV-visible (DR UV-vis) spectra revealed that the increased Ga/C ratio resulted in the increased formation of Ga2O3. Furthermore, all the prepared composite samples also showed visible light absorption up to about 430 nm. In the photocatalytic removal of cyclohexane under 6 h of visible light irradiation, sample with low loading of 1 mol% Ga/C improved the photocatalytic activity of carbon nitride for two times. The high activity obtained on the gallium oxide (1 mol%)/carbon nitride composite clearly suggested the presence of synergic effect between small amount of gallium oxide and carbon nitride when they were combined. This study showed that a visible light-driven gallium oxide/carbon nitride composite could be prepared by impregnating a small amount of gallium oxide on carbon nitride and the composite is a potential photocatalyst for removal of cyclohexane under visible light irradiation.  


RSC Advances ◽  
2016 ◽  
Vol 6 (57) ◽  
pp. 51801-51806 ◽  
Author(s):  
Jinwen Shi ◽  
Shichao Zong ◽  
Yuchao Hu ◽  
Xiangjiu Guan ◽  
Jiaying Luo ◽  
...  

(Na0.5La0.5TiO3)1−x(LaCrO3)x solid solutions showed enhanced visible-light-driven photocatalytic activities for H2 evolution due to the narrowed bandgaps and increased lattice distortion.


Author(s):  
Rong Fu ◽  
Ziye Pan ◽  
Xiaowei Mu ◽  
Jiayang Li ◽  
Qingyun Zhan ◽  
...  

Efficient ammonia synthesis was achieved by Mo, Pt modified TiO2−x under visible light irradiation. Pt nanoparticles trigger hydrogen spillover from Pt to Mo, enabling facile NH3 assembly and desorption, as well as increasing free Mo active sites.


2010 ◽  
Vol 162 ◽  
pp. 29-40 ◽  
Author(s):  
Ryo Niishiro ◽  
Akihiko Kudo

This review paper represents photocatalytic properties of metal cation-doped TiO2 (rutile) and SrTiO3 photocatalysts for O2 evolution from an aqueous silver nitrate solution and H2 evolution from an aqueous methanol solution under visible light irradiation. Photocatalytic activities for the O2 evolution of Cr/Sb and Rh/Sb-codoped TiO2 are strongly dependent on the codoping ratio and the amount of doped chromium and rhodium. The codopant controls the oxidation number of doped chromium and rhodium. Rh-doped SrTiO3 in which the doped Rh species possesses a reversible redox property is active for the H2 evolution reaction under visible light irradiation. Overall water splitting under visible light irradiation proceeds with Z-scheme photocatalyst systems consisting of the Rh-doped SrTiO3 as a H2 evolution photocatalyst combined with BiVO4 as an O2 evolution photocatalyst and an Fe3+/Fe2+ electron mediator.


RSC Advances ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 6383-6394 ◽  
Author(s):  
Haishuai Li ◽  
Linlin Cai ◽  
Xin Wang ◽  
Huixian Shi

A noval ternary nanocomposite AgCl/Ag3PO4/g-C3N4 was successfully synthesized for photocatalytic degradation of methylene blue, methylparaben and inactivation of E. coli under visible light irradiation, showing excellent photocatalytic degradation performance and stability.


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