(2023) Journal of Colloid and Interface Science_Direct growth of nano-worm-like Cu₂S on copper mesh as a hierarchical 3D catalyst for Fenton-like degradation of an imidazolium room-temperature ionic liquid in water

Xin-Yu Jiang, Eilhann Kwon, Jet-Chau Wen, Jorge Bedia, Bui Xuan Thanh, Suresh Ghotekar, Jechan Lee, Yu-Chih Tsai, Afshin Ebrahimi h, Kun-Yi Andrew Lin

The increasing consumption of room-temperature ionic liquids (RTILs) inevitably releases RTILs into the water environment, posing serious threats to aquatic ecology due to the toxicities of RTILs. Thus, urgent needs are necessitated for developing useful processes for removing RTILs from water, and 1-butyl-3-methylimidazolium chloride (C4mimCl), the most common RTIL, would be the most representative RTIL for studying the removal of RTILs from water. As advanced oxidation processes with hydrogen peroxide (HP) are validated as useful approaches for eliminating emerging contaminants, developing advantageous heterogeneous catalysts for activating HP is the key to the successful degradation of C4mim. Herein, a hierarchical structure is fabricated by growing Cu₂S on copper mesh (CSCM) utilizing CM as a Cu source. Compared to its precursor, CuO@CM, this CSCM exhibited tremendously higher catalytic activity for catalyzing HP to degrade C4mim efficiently because CSCM exhibits much more superior electrochemical properties and reactive sites, allowing CSCM to degrade C4mim rapidly. CSCM also exhibits a smaller Ea of C4mim elimination than all values in the literature. CSCM also shows a high capacity and stability for activating HP to degrade C4mim in the presence of NaCl and seawater. Besides, the mechanistic investigation of C4mim elimination by CSCM-activated HP has also been clarified and ascribed to OH and ¹O₂. The elimination route could also be examined and disclosed in detail through the quantum computational chemistry, confirming that CSCM is a useful catalyst for catalyzing HP to degrade RTILs.

This work is supported by the National Science and Technology Council (NSTC-112-2636-E-005-003), Taiwan, and financially supported by the “Innovation and Development Center of Sustainable Agriculture” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE), Taiwan. The authors gratefully acknowledge the use of SQUID000200 of MOST111-2731-M-006-001 belonging to the Core Facility Center of National Cheng Kung University.