Fabrication of a TiO2 trapped meso/macroporous g-C3N4 heterojunction photocatalyst and understanding its enhanced photocatalytic activity based on optical simulation analysis

2018 ◽  
Vol 5 (2) ◽  
pp. 481-489 ◽  
Author(s):  
Wanbao Wu ◽  
Xu Li ◽  
Zhaohui Ruan ◽  
Yudong Li ◽  
Xianzhu Xu ◽  
...  

The enhanced photocatalytic performance of a TiO2 nanoparticle trapped meso/macroporous g-C3N4 heterojunction photocatalyst is strongly related to its enhanced light absorption as revealed by optical simulation.

RSC Advances ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 6643-6650 ◽  
Author(s):  
Lijuan Han ◽  
Zheng Ma ◽  
Zhihe Luo ◽  
Gang Liu ◽  
Jiantai Ma ◽  
...  

The precursor with nanotubes structure can be hydrogenated easily in lower temperature comparing with nanobelts. The light absorption and photocatalytic activity of hydrogenated TiO2 nanotubes were enhanced drastically.


2021 ◽  
Vol 21 (4) ◽  
pp. 2647-2652
Author(s):  
Yanchen Ji ◽  
Guoxin Song ◽  
Ruiqi Yang ◽  
Longhua Ding ◽  
Aizhu Wang ◽  
...  

In this work, CeO2 nanocrystal-decorated TiO2 nanobelt for forming a CeO2@TiO2 heterostructure. CeO2 plays a dual role in improving photocatalytic activity, not only by promoting the separation and transfer of photogenerated charge carriers, but also by increasing visible light absorption of the photocatalyst as a photosensitizer. The as-prepared CeO2@TiO2 heterostructure demonstrates the performance of organic degradation and H2 production (about 17 μmol/h/g, which is about 2.5 times higher than that of pure TiO2 nanobelts). Our work provides a facile and controllable synthesis method for high performance photocatalyst, which will have potential applications in synthesis clean/solar fuel, and photocatalytic water treatment.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Chongjun Wang ◽  
Zaiwang Zhao ◽  
Bin Luo ◽  
Min Fu ◽  
Fan Dong

Various nitrogen-doped hierarchical (BiO)2CO3nanosheets architectures were synthesized by a facile one-step template-free hydrothermal method through controlling the hydrothermal temperature (HT). The as-synthesized samples were characterized by XRD, SEM, FT-IR, XPS, and UV-vis DRS. The photocatalytic activity of the samples was evaluated towards degradation of NO at ppb level in air under visible light (VIL). It was found that HT acted as a crucial factor in determining the morphology of the samples. The rosa chinensis-like, red camellia-like, and lamina-like of nitrogen-doped (BiO)2CO3(N-BOC) micro-/nanostructures can be selectively fabricated under hydrothermal temperatures of 150, 180, and 210°C. The thickness of the nanosheets was in direct proportion to the increasing HT. Nitrogen-doping can extend the light absorption spectra of (BiO)3CO3to visible light region and enhance the VIL photocatalytic activity. Especially, the red camellia-like N-BOC-180 exhibited the highest photocatalytic performance, superior to the well-known VIL-driven photocatalyst C-doped TiO2and N-doped TiO2. The high photocatalytic performance of N-BOC was attributed to the synergetic effects of enhanced visible light absorption, multiple light-reflections between the nanosheets, and accelerated transfer of reactants and product. This research could provide new insights to the development of excellent photocatalyst with efficient performance for pollution control.


Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 344 ◽  
Author(s):  
Xiong Sun ◽  
Hui-Jun Li ◽  
Nanquan Ou ◽  
Bowen Lyu ◽  
Bojie Gui ◽  
...  

Nitrogen doped graphene quantum dots (NGQDs) were successfully prepared via a hydrothermal method using citric acid and urea as the carbon and nitrogen precursors, respectively. Due to different post-treatment processes, the obtained NGQDs with different surface modifications exhibited blue light emission, while their visible-light absorption was obviously different. To further understand the roles of nitrogen dopants and N-containing surface groups of NGQDs in the photocatalytic performance, their corresponding composites with TiO2 were utilized to degrade RhB solutions under visible-light irradiation. A series of characterization and photocatalytic performance tests were carried out, which demonstrated that NGQDs play a significant role in enhancing visible-light driven photocatalytic activity and the carrier separation process. The enhanced photocatalytic activity of the NGQDs/TiO2 composites can possibly be attributed to an enhanced visible light absorption ability, and an improved separation and transfer rate of photogenerated carriers.


RSC Advances ◽  
2016 ◽  
Vol 6 (85) ◽  
pp. 82409-82416 ◽  
Author(s):  
Ping Wu ◽  
Guoming Wang ◽  
Ruizhi Chen ◽  
Yixin Guo ◽  
Xueming Ma ◽  
...  

[KNbO3]1−x[BaNi0.5Nb0.5O3−δ]x were synthesized by Pechini sol–gel method at low temperature. Visible light photocatalytic performance of this material was evaluated.


2017 ◽  
Vol 5 (40) ◽  
pp. 21300-21312 ◽  
Author(s):  
Yudong Li ◽  
Yanqiu Jiang ◽  
Zhaohui Ruan ◽  
Kaifeng Lin ◽  
Zhuobin Yu ◽  
...  

Millimeter-scale g-C3N4 beads with 3D continuous meso/macropore channels are synthesized guided by optical simulation confirming enhanced light absorption.


RSC Advances ◽  
2017 ◽  
Vol 7 (63) ◽  
pp. 40028-40033 ◽  
Author(s):  
Hao Xu ◽  
Zhixing Gan ◽  
Weiping Zhou ◽  
Zuoming Ding ◽  
Xiaowei Zhang

Insufficient visible light absorption and fast recombination of the photogenerated electron–hole pairs have seriously hampered the photocatalytic performance of graphitic carbon nitride (g-C3N4) up to now.


RSC Advances ◽  
2015 ◽  
Vol 5 (123) ◽  
pp. 101552-101562 ◽  
Author(s):  
Zhao Mo ◽  
Xiaojie She ◽  
Yeping Li ◽  
Liang Liu ◽  
Liying Huang ◽  
...  

The visible light absorption of g-C3N4 was extended through controlling the synthesis temperature, and thus enhanced visible/UV photocatalytic activity. Moreover, g-C3N4 can also be used as a photoelectrochemical sensor.


Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>


2019 ◽  
Vol 8 (1) ◽  
pp. 56-61
Author(s):  
Aneeya K. Samantara ◽  
Debasrita Dash ◽  
Dipti L. Bhuyan ◽  
Namita Dalai ◽  
Bijayalaxmi Jena

: In this article, we explored the possibility of controlling the reactivity of ZnO nanostructures by modifying its surface with gold nanoparticles (Au NPs). By varying the concentration of Au with different wt% (x = 0.01, 0.05, 0.08, 1 and 2), we have synthesized a series of (ZnO/Aux) nanocomposites (NCs). A thorough investigation of the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface has been carried out. It was observed that ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity among all concentrations of Au on the ZnO surface, which degrades the dye concentration within 2 minutes of visible light exposure. It was further revealed that with an increase in the size of plasmonic nanoparticles beyond 0.08%, the accessible surface area of the Au nanoparticle decreases. The photon absorption capacity of Au nanoparticle decreases beyond 0.08% resulting in a decrease in electron transfer rate from Au to ZnO and a decrease of photocatalytic activity. Background: Due to the industrialization process, most of the toxic materials go into the water bodies, affecting the water and our ecological system. The conventional techniques to remove dyes are expensive and inefficient. Recently, heterogeneous semiconductor materials like TiO2 and ZnO have been regarded as potential candidates for the removal of dye from the water system. Objective: To investigate the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface and the effect of the size of Au NPs for photocatalytic performance in the degradation process. Methods: A facile microwave method has been adopted for the synthesis of ZnO nanostructure followed by a reduction of gold salt in the presence of ZnO nanostructure to form the composite. Results: ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity which degrades the dye concentration within 2 minutes of visible light exposure. The schematic mechanism of electron transfer rate was discussed. Conclusion: Raspberry shaped ZnO nanoparticles modified with different percentages of Au NPs showed good photocatalytic behavior in the degradation of dye molecules. The synergetic effect of unique morphology of ZnO and well anchored Au nanostructures plays a crucial role.


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