A thiolated TiO2-based degradable superhydrophobic wood for oil–water separation and heavy metal treatment

• Published in: Separation and purification technology Vol. 354; p. 128949
• Main Authors: Chen, Zhuohan, Su, Xiaojing, Li, Kunquan, Niu, Shaoxing, Shen, Zibin, Li, Xuanjun, Chen, Shengye, Wu, Wenjian
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 19.02.2025
• Subjects: Heavy metal adsorption; Heavy metal detection; Oil–water separation; Photocatalysis; Superhydrophobic wood; Superhydrophobic wood; Oil–water separation; Heavy metal detection; Photocatalysis; Heavy metal adsorption
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2024.128949

•A superhydrophobic wood for oil–water separation and heavy metal detection is proposed.•The wood presents stable oil–water separation for the robust structure by pre-curing method.•The wood exhibits high sensitivity for heavy metal detection and adsorption via thiol–metal complexation.•The wood possesses good photodegradation capability to prevent secondary pollution. The discharge of pollutants, including oily wastewater and heavy metal ions, into water has been on the rise, posing significant risks to environmental integrity and public health. Moreover, the heavy metal ions that cause more serious damages are easily neglected in oil–water separation. Herein, a superhydrophobic wood with photocatalytic capability for fast oil–water separation and heavy metal detection was designed and prepared via coating epoxy resin (ER) and sulfhydryl modified titanium dioxide (s-TiO2) on the wood through a pre-curing method. Owing to the special porous structure and superhydrophobicity of the s-TiO2@ER wood, the oil–water mixture was successfully separated with a separation flux of 11,350 kg·m−2·h−1 and separation efficiency of 99.3 %. Due to the pre-curing method, the s-TiO2 was adhered to ER surface with the −SH groups exposed to the outermost, which was beneficial for the detection and adsorption of heavy metal ions. When adsorbing heavy ions of Cu2+, Fe3+, Co2+, and Cr3+, the s-TiO2@ER wood displayed colors of green, yellow, pink, and brown, respectively, which could be used in heavy metal detection during the oil–water separation process. Importantly, the s-TiO2@ER wood exhibited a high heavy metal adsorption efficiency with the Cu2+ ion adsorption capability reaching 137 mg/g. Furthermore, the s-TiO2@ER wood demonstrated a good photodegradation capability, and the organic pollutants adsorbed on the wood after use could be degraded to prevent secondary pollution. This work provides a porous photocatalytic superhydrophobic wood with high oil–water separation efficiency and excellent heavy metal detection and adsorption ability, which is promising in the field of treating complex oily wastewater containing heavy metals.