scholarly journals Fabrication of Rh-doped TiO2 nanofibers for Visible Light Degradation of Rhodamine B

2011 ◽  
Vol 1352 ◽  
Author(s):  
Emilly A. Obuya ◽  
William Harrigan ◽  
Tim O’Brien ◽  
Dickson Andala ◽  
Eliud Mushibe ◽  
...  

ABSTRACTThe synthesis and application of environmentally benign, efficient and low cost heterogeneous catalysts is increasingly important for affordable and clean chemical technologies. Nanomaterials have been proposed to have new and exciting properties relative to their bulk counterparts due to the quantum level interactions that exist at nanoscale. These materials also offer enormous surface to volume ratios that would be invaluable in heterogeneous catalysis. Recent studies point at titanium dioxide nanomaterials as having strong potential to be applied in heterogeneous photocatalysis for environmental remediation and pollution control. This work reports the use of surface modified anatase TiO2 nanofibers with rhodium (Rh) nanoparticles in the photodegradation of rhodamine B (RH-B), an organic pollutant. The dimensions of TiO2 nanofibers were 150±50 nm in diameter and the size of the Rh nanoparticles was ~5 nm. The Rh-doped TiO2 catalyst exhibited an enhanced photocatalytic activity in photodegradation of rhodamine B under visible light irradiation, with 95 % degradation within 180 minutes reaction time. Undoped TiO2 did not show any notable phocatalytic activity under visible light.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Khee Chung Hui ◽  
Hazwani Suhaimi ◽  
Nonni Soraya Sambudi

Abstract Titanium dioxide (TiO2) is commonly used as a photocatalyst in the removal of organic pollutants. However, weaknesses of TiO2 such as fast charge recombination and low visible light usage limit its industrial application. Furthermore, photocatalysts that are lost during the treatment of pollutants create the problem of secondary pollutants. Electrospun-based TiO2 fiber is a promising alternative to immobilize TiO2 and to improve its performance in photodegradation. Some strategies have been employed in fabricating the photocatalytic fibers by producing hollow fibers, porous fibers, composite TiO2 with magnetic materials, graphene oxide, as well as doping TiO2 with metal. The modification of TiO2 can improve the absorption of TiO2 to the visible light area, act as an electron acceptor, provide large surface area, and promote the phase transformation of TiO2. The improvement of TiO2 properties can enhance carrier transfer rate which reduces the recombination and promotes the generation of radicals that potentially degrade organic pollutants. The recyclability of fibers, calcination effect, photocatalytic reactors used, operation parameters involved in photodegradation as well as the commercialization potential of TiO2 fibers are also discussed in this review.


RSC Advances ◽  
2014 ◽  
Vol 4 (110) ◽  
pp. 64747-64755 ◽  
Author(s):  
Xuefeng Xu ◽  
Man Wang ◽  
Yanyan Pei ◽  
Changchun Ai ◽  
Liangjie Yuan

The micro/nano-structure composite SiO2@Ag/AgCl was employed as a low cost photocatalyst for the degradation of RhB in aqueous solution under visible light irradiation, which exhibited excellent photocatalytic performance and stability.


2021 ◽  
Vol 10 (2) ◽  
pp. 59-63
Author(s):  
Hai Pham Viet ◽  
Anh Dao Thi Ngoc ◽  
Viet Nguyen Minh ◽  
Ha Tran Thi Viet ◽  
Dang Do Van ◽  
...  

In this study, direct Z–scheme heterostructure CoWO4/g-C3N4 was synthesized by a facile hydrothermal method. The structural, morphological properties of the prepared samples were characterised by XRD, SEM, UV–Vis and PL measurements. The as-obtained heterostructure CoWO4/g-C3N4 exhibited enhanced photocatalytic activities toward the degradation of Rhodamine B under visible light irradiation with 92% Rhodamine B removal after 80 minutes irritation, which exceeded pristine g-C3N4 and CoWO4. The enhanced photocatalytic performance ascribed to interfacial contact between g-C3N4 and CoWO4, thus further inhibiting the recombination of photogenerated electron/hole pairs. It is anticipated that the construction of Z–scheme heterostructure CoWO4/g-C3N4 is an effective strategy to develop high-performance photocatalysts for the degradation of organic pollutants in water.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Tan Lam Nguyen ◽  
Viet Dinh Quoc ◽  
Thi Lan Nguyen ◽  
Thi Thanh Thuy Le ◽  
Thanh Khan Dinh ◽  
...  

A low-cost and simplistic approach for the synthesis of nanosized SO42-/TiO2 photocatalyst was successfully performed using Binh Dinh ilmenite ore and H2SO4 as titanium and sulfur sources, respectively. The experimental results indicate that the obtained material exists in the form of particles with a size of about 22 nm and has a specific surface area of about 49 m2 g-1. Compared with the TiO2 sample, the SO42-/TiO2 sample shows much higher photocatalytic degradation of rhodamine B (RhB) under the sunlight irradiation. In more details, the nanosized SO42-/TiO2 sample obtained is capable of completely decomposing RhB after 9 hours of irradiation by a 60 W LED lamp with a corresponding intensity of 9,500 Lux. However, when the SO42-/TiO2 is irradiated by the sunlight with the intensity of 65,000 Lux, it only takes 2 hours to completely decompose rhodamine B (RhB), facilitating the use of SO42-/TiO2 as a potential photocatalyst for the RhB photodegradation.


Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2801
Author(s):  
Guang Feng ◽  
Mengyun Hu ◽  
Shuai Yuan ◽  
Junyi Nan ◽  
Heping Zeng

Hydrogenated crystalline TiO2 with oxygen vacancy (OV) defect has been broadly investigated in recent years. Different from crystalline TiO2, hydrogenated amorphous TiO2−x for advanced photocatalytic applications is scarcely reported. In this work, we prepared hydrogenated amorphous TiO2−x (HA-TiO2−x) using a unique liquid plasma hydrogenation strategy, and demonstrated its highly visible-light photoactivity. Density functional theory combined with comprehensive analyses was to gain fundamental understanding of the correlation among the OV concentration, electronic band structure, photon capturing, reactive oxygen species (ROS) generation, and photocatalytic activity. One important finding was that the narrower the bandgap HA-TiO2−x possessed, the higher photocatalytic efficiency it exhibited. Given the narrow bandgap and extraordinary visible-light absorption, HA-TiO2−x showed excellent visible-light photodegradation in rhodamine B (98.7%), methylene blue (99.85%), and theophylline (99.87) within two hours, as well as long-term stability. The total organic carbon (TOC) removal rates of rhodamine B, methylene blue, and theophylline were measured to 55%, 61.8%, and 50.7%, respectively, which indicated that HA-TiO2−x exhibited high wastewater purification performance. This study provided a direct and effective hydrogenation method to produce reduced amorphous TiO2−x which has great potential in practical environmental remediation.


2021 ◽  
Vol 21 (4) ◽  
pp. 2292-2301
Author(s):  
Gabriela Spirandelli dos Santos ◽  
Clarice Moreira Goes ◽  
Juliana Giancoli Martins de Sousa ◽  
Nicolas Perciani de Moraes ◽  
Livia Chaguri ◽  
...  

This study is focused on the evaluation of the Rhodamine B photodegradation using ZnO/carbon xerogel composite as a photocatalyst, in order to enhance the photocatalytic process efficiency under visible light. The proposed synthesis employs tannin as a precursor for the carbon xerogel, which enhances the economic and environmental aspect of the composite. The synthesized materials have the hexagonal structure of the zinc oxide (wurtzite), which is homogeneously distributed on the carbonaceous matrix. The diffuse reflectance test shows that light absorption was significantly enhanced for the composite. The solar light-driven photodegradation results revealed that the synthesized composite achieved virtually complete degradation of the dye present in the solution in less than 3 h, in all concentrations tested. The results of visible light driven photocatalysis showed that the carbonaceous material presents better photoactivity than the pure oxide (70% and 40% degradation of Rhodamine B, respectively), due to the synergistic effect between the carbon xerogel and zinc oxide on the properties of the composite. The photocatalytic mechanism main active species are the photogenerated vacancies and superoxide radicals.


2014 ◽  
Vol 193 ◽  
pp. 154-159 ◽  
Author(s):  
Jianfeng Ma ◽  
Liangyin Li ◽  
Jing Zou ◽  
Yong Kong ◽  
Sridhar Komarneni

2001 ◽  
Vol 73 (12) ◽  
pp. 1849-1860 ◽  
Author(s):  
Krishnan Rajeshwar ◽  
C. R. Chenthamarakshan ◽  
Scott Goeringer ◽  
Miljana Djukic

Using hexavalent chromium [Cr(VI)] and methylene blue (MB) as model substrates, we discuss three aspects of TiO2-based heterogeneous photocatalysis. We show first that a given TiO2 sample may not be simultaneously optimal for photocatalytically driving the reduction of Cr(VI) and the oxidation of MB. We further show that a TiO2 sample that strongly adsorbs either of these substrates in the dark is not optimal as a photocatalyst. The other two aspects concern circumventing the rather poor surface catalytic properties and visible light photoresponse of TiO2, respectively. Strategies revolving around the visible light photoexcitation of the substrate itself and metal-modification of the TiO2 surface, are described as possible solutions.


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