Phenol Molecular Sheets Woven by Water Cavities in Hydrophobic Slit Nanospaces Piotr Kowalczyk,* ,† Marek Wis ́ niewski, ‡ Artur Deditius, † Jerzy Wloch, ‡ Artur P. Terzyk, ‡ Wendell P. Ela, † Katsumi Kaneko, § Paul A. Webley, ∥ and Alexander V. Neimark ⊥ † School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch 6150, Western Australia, Australia ‡ Physicochemistry of Carbon Materials Research Group, Faculty of Chemistry, N. Copernicus University in Toruń , 7 Gagarin Street, 87-100 Toruń , Poland § Center for Energy and Environmental Science, Shinshu University, 4-17-1, Wakasato, Nagano-City 380-8553, Japan ∥ School of Chemical and Biomedical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia ⊥ Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854-8058, United States *S Supporting Information ABSTRACT: Despite extensive research over the last several decades, the microscopic characterization of topological phases of adsorbed phenol from aqueous solutions in carbon micropores (pore size < 2.0 nm), which are believed to exhibit a solid and quasi-solid character, has not been reported. Here, we present a combined experimental and molecular level study of phenol adsorption from neutral water solutions in graphitic carbon micropores. Theoretical and experimental results show high adsorption of phenol and negligible coadsorption of water in hydrophobic graphitic micropores (super-sieving effect). Graphic processing unit-accelerated molecular dynamics simulation of phenol adsorption from water solutions in a realistic model of carbon micropores reveal the formation of two-dimensional phenol crystals with a peculiar pattern of hydrophilic−hydrophobic stripes in 0.8 nm supermicropores. In wider micropores, disordered phenol assemblies with water clusters, linear chains, and cavities of various sizes are found. The highest surface density of phenol is computed in 1.8 nm supermicropores. The percolating water cluster spanning the entire pore space is found in 2.0 nm supermicropores. Our findings open the door for the design of better materials for purification of aqueous solutions from nonelectrolyte micropollution. 1. INTRODUCTION Adsorption processes are playing a central role in water purification and clean-up from nonelectrolyte micropollution including toxic industrial chemicals, dyes, chlorine and chloramines, pesticides, pharmaceuticals, personal care prod- ucts, and endocrine-disrupting chemicals, amongst others. 1 It has been estimated that ∼80% of industrial water contaminates are phenolic derivatives. 2 Of these, most compounds are recognized as toxic carcinogens. 2 Thus, is it not surprising that phenol, a planar molecule with a hydroxyl group attached to the benzene ring, is a recommended probe for testing potential adsorbents for water purification and clean-up by adsorption processes. 3,4 Nanoporous carbon adsorbents, such as granular activated carbons (GACs) produced from natural precursors and activated carbon fibers (ACFs), have been used in portable water purification systems and water treatment plants for the production of clean drinking water. 5,6 It is generally accepted that the wettability and the nanopore structure of carbon adsorbents are the most important properties for the optimization of their performance toward adsorptive removal of nonelectrolyte contaminates. 7−9 Yet, the specifics of competitive solute−water adsorption in nanopores of the Received: August 20, 2018 Revised: October 23, 2018 Published: November 17, 2018 Article pubs.acs.org/Langmuir Cite This: Langmuir 2018, 34, 15150-15159 © 2018 American Chemical Society 15150 DOI: 10.1021/acs.langmuir.8b02832 Langmuir 2018, 34, 15150−15159 Downloaded by UNIV COLLEGE LONDON at 07:34:16:748 on June 19, 2019 from https://pubs.acs.org/doi/10.1021/acs.langmuir.8b02832.