Synthesis of activated carbon-supported TiO2-based nano-photocatalysts with well recycling for efficiently degrading high-concentration pollutants

• Published in: Catalysis today Vol. 335; pp. 557 - 564
• Main Authors: Ali, Sharafat, Li, Zhijun, Chen, Shuangying, Zada, Amir, Khan, Iltaf, Khan, Imran, Ali, Wajid, Shaheen, Shabana, Qu, Yang, Jing, Liqiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-09-2019
• Subjects: Good recycling; High-concentration pollutants; Modification; Photocatalysis; TiO2; Modification; High-concentration pollutants; Good recycling; Photocatalysis; TiO2
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2019.03.044

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•TiO2/AC is fabricated for photocatalytic degrading high-concentration pollutants.•The activities are improved by constructing heterojunction with SrTiO3.•The activities are further improved by modifying phosphoric acid.•Exceptional photoactivities mainly depend on the enhanced charge separation.•Charge separation is due to the improved charge transfer and O2 adsorption.
It is highly desired to develop efficient TiO2-based nano-photocatalysts with excellent recycling properties for practical application to degrade high-concentration pollutants. Herein, TiO2 nanoparticles have been successfully modified by coupling activated carbon (AC), constructing heterojunction with SrTiO3 and modifying with phosphoric acid. It is clearly demonstrated that the as-prepared nano-photocatalysts exhibit exceptional photoactivities for degrading high-concentration pollutants like 2,4-dichlorophenol (2,4-DCP) and bisphenol A (BPA), both with ∼3-time activity enhancement compared to commercial P25 TiO2. Based on the surface photovoltage responses and the fluorescence spectra related to the formed OH amounts, it is deduced that the exceptional photocatalytic activities are attributed to the coupled AC for accepting electrons and promoting reactant adsorption, to the formed SrTiO3 for inhibiting the anatase TiO2 crystallite growth to increase the surface area and promoting the charge separation, and to the modified phosphate groups for promoting the adsorption of O2 to enhance the charge separation. Furthermore, it is demonstrated through the radical trapping experiments that the photogenerated hydroxyl radicals could be dominant for the photocatalytic degradation of 2,4-DCP. This work would provide a feasible route to obviously enhance the photocatalytic activities of TiO2-based nano-photocatalysts for the environmental remediation with good recycling properties.