Joule-heatable bird-nest-bioinspired/carbon nanotubes-modified sepiolite porous ceramics: An efficient, sturdy, and continuous strategy for oil recovery

Abstract

Oil-spill accident is a severe globally concerned environmental issue. In this work, a Joule-heatable bird-nest-bioinspired/carbon nanotubes-modified sepiolite porous ceramic (JBN/CM-SC) was developed, using inexpensive sepiolite porous ceramics as the substrate and carbon nanotubes (CNTs) derived from waste plastics as the modifier. The former exhibited outstanding mechanical property (1.7 MPa of compressive strength), gas permeability (9.1 × 10−11 m2), thermal conductivity (0.215 W·m−1·K−1) and thermal/chemical stability. As expected, the deposited CNTs not only conferred a hydrophobic surface, but also resulted in a Joule-heating ability of intrinsically non-conductive ceramics. As-prepared JBN/CM-SC demonstrated a separation rate as high as 120−200 kg·s−1·m−2 for oil recovery and a high selectivity of over 95%. The Joule heat generated by the heated JBN/CM-SC could in-situ reduce the oil-viscosity, remarkably increasing the oil-diffusion. The separation rate was enhanced by ~12 times with respect to that of the non-heated counterpart. In addition, the idea of modular design was proposed. By simply combining JBN/CM-SC components with pipes and a pump, a continuous in-situ collection of oil from an oil/water mixture was realized, providing an efficient, sturdy, and continuous approach to recover the spilled oil in an oil-spill accident.