scholarly journals N,Cu-CD-Decorated Mesoporous WO3 for Enhanced Photocatalysis Under UV–Vis–NIR Light Irradiation

2021 ◽  
Vol 8 ◽  
Author(s):  
Tianjun Ni ◽  
Qiansheng Li ◽  
Yunhui Yan ◽  
Zhijun Yang ◽  
Kaiwen Chang ◽  
...  

Research on the design of semiconductor photocatalysts with rapid electron transfer efficiencies and broad-spectrum responses for environmental remediation remains a pressing challenge. Herein, we described the fabrication of a novel broad-spectrum nitrogen and copper codoped carbon dots/mesoporous WO3 nanocomposite (N,Cu-CDs/m-WO3), which exhibited complete UV–vis–NIR spectrum response, light harvesting capabilities, rich oxygen vacancies, rapid electron-transfer ability, low electron–hole (e−/h+) pair recombination rate, and extensive specific surface area. After 2 h of photocatalytic reaction, it showed excellent photoactivities for the degradation of rhodamine B, methylene blue, tetracycline hydrochloride, oxytetracycline, ciprofloxacin, and bisphenol A. Moreover, we found that the conversion between Cu (II) and Cu (I) played a key role in accelerating electron transfer and inhibiting the recombination of e−/h+ pairs. This work provides an efficient strategy for the utilization of solar light and enhancing the charge-transfer capacity in the semiconductor photocatalysis field.

2020 ◽  
Vol 20 (2) ◽  
pp. 314 ◽  
Author(s):  
Hassan Khuder Naji ◽  
Amjed Mirza Oda ◽  
Wesam Abdulaljeleel ◽  
Hussein Abdilkadhim ◽  
Rawaa Hefdhi

Two films of ZnO-Ag/polystyrene (ZnO-Ag/PS) and ZnO/polystyrene (ZnO/PS) have been prepared to evaluate the photodegradation ability of stabilized catalysts. The efficiency of ZnO improved against recombination of electron-hole pair by modification of catalyst surface with Ag photodeposition to be more resistant towards photocorrosion. ZnO-Ag catalyst was characterized by SEM and EDS analysis to show high roughness of this catalyst and Ag deposited on the surface was 2% (molar ratio). ZnO-Ag/PS and ZnO/PS composites were made as films and were then analyzed by FTIR spectra that showed the interaction of ZnO and ZnO-Ag with polystyrene appeared in the range of 400–620 cm–1, XRD pattern indicated the presence of Ag nanoparticles on the surface of ZnO and ZnO/PS film has maximum absorbance at 376 nm in UV-VIS spectra. This value shifted to 380 nm because of the photodeposition. The photocatalytic reaction was depicted using methylene blue (MB) in the UV-irradiation action of stacked films in MB solution. The result showed that both ZnO-Ag/PS and ZnO/PS films gave efficiency to remove MB by 97% and 70%, respectively. The reusability test of the films showed that ZnO-Ag/PS was more resistant than ZnO/PS. The presence of Ag also increased the efficiency in photodegradation and resistance against photocorrosion.


RSC Advances ◽  
2021 ◽  
Vol 11 (20) ◽  
pp. 11872-11881
Author(s):  
Xinye Zhang ◽  
Xueyue Zhang ◽  
Keting Feng ◽  
Xiaoyun Hu ◽  
Jun Fan ◽  
...  

A CdSe/C/TiO2 nanofiber film was prepared for enhanced photoelectrochemical degradation ability, and carbon membrane as a carrier-transfer-channel could promote electron transfer.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 589
Author(s):  
Sivagowri Shanmugaratnam ◽  
Balaranjan Selvaratnam ◽  
Aravind Baride ◽  
Ranjit Koodali ◽  
Punniamoorthy Ravirajan ◽  
...  

Earth–abundant transition metal chalcogenide materials are of great research interest for energy production and environmental remediation, as they exhibit better photocatalytic activity due to their suitable electronic and optical properties. This study focuses on the photocatalytic activity of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized by a facile hydrothermal method. The materials were characterized using different techniques, and their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of methylene blue. Among the catalysts studied, 10 wt. % of SnS2 loaded TiO2 nanocomposite shows an optimum hydrogen evolution rate of 195.55 µmolg−1, whereas 15 wt. % loading of SnS2 on TiO2 exhibits better performance against the degradation of methylene blue (MB) with the rate constant of 4.415 × 10−4 s−1 under solar simulated irradiation. The improved performance of these materials can be attributed to the effective photo-induced charge transfer and reduced recombination, which make these nanocomposite materials promising candidates for the development of high-performance next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger, whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These results further validate that the •OH radical and the superoxide radicals can be acknowledged for the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap materials on TiO2.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 850 ◽  
Author(s):  
Ladislav Svoboda ◽  
Nadia Licciardello ◽  
Richard Dvorský ◽  
Jiří Bednář ◽  
Jiří Henych ◽  
...  

In the majority of photocatalytic applications, the photocatalyst is dispersed as a suspension of nanoparticles. The suspension provides a higher surface for the photocatalytic reaction in respect to immobilized photocatalysts. However, this implies that recovery of the particles by filtration or centrifugation is needed to collect and regenerate the photocatalyst. This complicates the regeneration process and, at the same time, leads to material loss and potential toxicity. In this work, a new nanofibrous membrane, g-C3N4/PMMA/PUR, was prepared by the fixation of exfoliated g-C3N4 to polyurethane nanofibers using thin layers of poly(methyl methacrylate) (PMMA). The optimal amount of PMMA was determined by measuring the adsorption and photocatalytic properties of g-C3N4/PMMA/PUR membranes (with a different PMMA content) in an aqueous solution of methylene blue. It was found that the prepared membranes were able to effectively adsorb and decompose methylene blue. On top of that, the membranes evinced a self-cleaning behavior, showing no coloration on their surfaces after contact with methylene blue, unlike in the case of unmodified fabric. After further treatment with H2O2, no decrease in photocatalytic activity was observed, indicating that the prepared membrane can also be easily regenerated. This study promises possibilities for the production of photocatalytic membranes and fabrics for both chemical and biological contaminant control.


2014 ◽  
Vol 4 (12) ◽  
pp. 4396-4405 ◽  
Author(s):  
Teo Peik-See ◽  
Alagarsamy Pandikumar ◽  
Lim Hong Ngee ◽  
Huang Nay Ming ◽  
Chia Chin Hua

Synthesis of magnetically separable rGO/Fe3O4nanocomposite materials for environmental remediationviathe photocatalytic degradation of methylene blue.


RSC Advances ◽  
2014 ◽  
Vol 4 (107) ◽  
pp. 62423-62429 ◽  
Author(s):  
Sara Rahimnejad ◽  
Jing Hui He ◽  
Wei Chen ◽  
Kai Wu ◽  
Guo Qin Xu

WO3 nanoplates derived from NiWO4 were found to have the highest concentration of oxygen vacancy, narrowest band gap, longest electron–hole recombination time, and in turn the highest rate of photodegradation of azo dye methylene blue.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Patcharanan Junploy ◽  
Titipun Thongtem ◽  
Somchai Thongtem ◽  
Anukorn Phuruangrat

SrSn(OH)6 precursors synthesized by a cyclic microwave radiation (CMR) process were calcined at 900°C for 3 h to form rod-like SrSnO3. Further, the rod-like SrSnO3 and AgNO3 in ethylene glycol (EG) were ultrasonically vibrated to form rod-like Ag/SrSnO3 composites, characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy (EM), Fourier transform infrared (FTIR) spectroscopy, and UV-visible analysis. The photocatalyses of rod-like SrSnO3, 1 wt%, 5 wt%, and 10 wt% Ag/SrSnO3 composites were studied for degradation of methylene blue (MB, C16H18N3SCl) dye under ultraviolet (UV) radiation. In this research, the 5 wt% Ag/SrSnO3 composites showed the highest activity, enhanced by the electron-hole separation process. The photoactivity became lower by the excessive Ag nanoparticles due to the negative effect caused by reduction in the absorption of UV radiation.


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