By Beijing Zhongke Journal Publishing Co. Ltd.
The cylindrical reactor is made of stainless steel with a diameter of 210 mm and a height of 210 mm. Ti grids (100 mm in length, 100 mm in width, and 0.5 mm in thickness) coated with TiO22 The nanotube arrays were fixed inside the reactor. A 100 W high-pressure mercury lamp (HPML) was placed inside the quartz tube. In addition, the inlet and outlet are designed on the left and right sides of the reactor respectively. The inlet was connected to the nanobubble generator. Wastewater was pumped into a bubble generator to prepare wastewater containing nanobubbles before entering the photocatalytic reactor. Han Group Art. Credit: Beijing Zhongke Journal Publishing Co., Ltd. Ltd.
With the rapid development of urbanization and industrialization, environmental problems are becoming increasingly serious. Dye wastewater is one of the biggest challenges because of its high toxicity. Organic pigments have mutagenic, teratogenic, and carcinogenic properties, threatening the health and life of humans while hindering plant photosynthesis, resulting in risks to the ecosystem. Traditional organic pollutant treatment methods include physical method, biological method, and chemical method.
These methods have disadvantages including poor efficiency, high energy consumption, and incomplete treatment, so it is necessary to develop new wastewater treatment methods. In 1972, Fujishima pioneered the photolysis of water to produce hydrogen using TiO22 as a photocatalyst. Subsequently, the photocatalytic technology was developed for wastewater treatment due to its advantages of superior mineralization ability, fast reaction rate, and no secondary pollution.
TiO2 It is a popular photocatalytic material because of its high catalytic activity, nontoxicity, excellent chemical stability, and low cost. For TiO application2 Photocatalytic technology, it is necessary to design a photocatalytic reactor with simple structure, convenient assembly and outstanding processing performance.
In recent years, photocatalytic technology has been coupled with several advanced redox processes (AOPs) to improve photocatalytic performance. TiO2Coupling of a photocatalytic technique based on classical AOPs such as Fenton oxidation, plasma oxidation and ozone oxidation has been reported to improve the processing of organic pollutants.
Nanoparticles (NBs) are extremely small gas bubbles with unique physical properties, making them a superior aeration method for many applications. Nanobubbles have been widely used in wastewater treatment due to their long residence time, large surface area, and ability to generate free radicals. The researchers designed UV/NBs/P.25-TiO2 A photoreactor for the decomposition of methyl orange in water. The results showed that the photocatalytic performance of titanium dioxide2 Conjugation with nanobubbles was improved by 11.6% compared to that without bubbles.
However, TiO2 The photocatalyst had to be re-separated and recovered after the photocatalytic decomposition, which was inconvenient for the photocatalytic reactor design. Therefore, a fixed photocatalyst was required to assemble the photocatalytic reactor.
A photocatalytic reactor was assembled using a TiO2-coated Ti grid2 Nanotube array to reduce organic pollutants. Coupling of the reactor with nanobubble technology demonstrated superior photocatalytic degradation capability, with a degradation efficiency for Rhodamine B (RhB) of 95.39% after irradiation. Other organic pollutants including methylene blue, tetracycline, and oxytetracycline hydrochloride were all photodegradable using this photocatalytic reactor, with decomposition efficiencies of 74.23%, 68.68%, and 64.10%, respectively. Therefore, this work provides a strategy for developing a coupling technique of photocatalysis and nanobubbles for wastewater treatment.
The study has been published in the journal Advanced sensor and energy materials.
more information:
Zesen Lin et al, Degradation of Rhodamine B in a photocatalytic reactor containing TiO nanotube arrays coupled to nanobubbles, Advanced sensor and energy materials (2023). DOI: 10.1016/j.asems.2023.100054
Provided by Beijing Zhongke Journal Publishing Co., Ltd. Ltd.
the quote: Improving Photocatalytic Technology Using TiO2 Nanotube Arrays and Nanobubbles (2023, May 16) Retrieved May 16, 2023 from https://phys.org/news/2023-05-photocatalytic-technology-tio2-nanotube-arrays.html
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