Photoinduced reactions occurring on activated carbons. A combined photooxidation and ESR study
Authors: Leticia F. Velasco, Valter Maurino, Enzo Laurenti, Isabel M. Fonseca, Joao C. Lima, Conchi O. Ania
Abstract:
This work demonstrates the ability of ash-free activated carbons to interact with UV light to promote the photooxidation of phenol in solution through the formation of radical species. Our results show that in the absence of inorganic impurities or semiconductor additives, the photodegradation efficiency of the studied activated carbons has to be ascribed to the carbon matrix itself. Hydroxyl radicals have been detected by spin trapping electron spin resonance spectroscopy upon UV irradiation of the activated carbon suspensions in aqueous solution. Although the ability to photogenerate radicals upon irradiation is well known in inorganic semiconductors (such as titanium dioxide) or carbon/semiconductor composites, we herein demonstrate the capacity of the carbon matrix alone to interact with UV light, generating reactive species that would be responsible for the observed photoinduced reaction using carbons alone in the absence of semiconductor additives. Thus, the conventional interpretation of the enhanced photodegradation efficiency of carbon/semiconductor photocatalysts -so far attributed to synergistic and confinement effects, and minimized surface recombination of the charge carriers- should be reconsidered to account for the radicals photogenerated when the carbons are exposed to UV light.
Keywords:
Hydroxyl radicals
Ash-free materials
Activated carbon
Photooxidation
Electron spin resonance
Published in: Applied catalysis A: General (Volume 452, Pages 1-222, 15 February 2013)
Publisher: Elsevier
ISSN Information: 0926-860X
Photoinduced reactions occurring on activated carbons. A combined photooxidation and ESR study
- Ngày hội Văn hóa đọc lần VI
- Vòng Sơ Khảo Cuộc Thi Đại Sứ Văn Hóa Đọc Năm 2024
- Ngày hội sách “CITTADELLA” khuyến khích và tôn vinh vai trò của sách trong sinh viên Bách khoa
- Cuộc Thi Ảnh “Khoảnh Khắc VNUHCM Libraries”
- Ngày hội văn hóa đọc lần V
- Ngày hội văn hóa đọc lần II
- Ngày hội văn hóa đọc lần IV
- Ngày hội văn hóa đọc lần III
- Tiếp GS Omer Mert Denizci, Trường ĐH Marmara Thổ Nhĩ Kỳ
- Tiếp Cô Claudia Tarzariol Từ The University Of Trento, Italy (Unitrento)
- Tiến sĩ kiều bào Mỹ tặng sách trị giá 150.000 USD cho sinh viên bách khoa
- Khảo sát ý kiến bạn đọc
-
Trực tuyến:4
-
Hôm nay:353
-
Tuần này:353
-
Tuần trước:33192
-
Tháng trước:33192
-
Tất cả:4055088