Solar-thermal anisotropic zeolitic imidazolate framework/reduced graphene oxide hybrid aerogels for efficient clean-up of heavy crude oil

Heavy crude oil rich in colloid and asphaltene is widely used in human life, but the collection and clean-up of its spills are difficult because of its high viscosity and low flowability. Herein, the zeolitic imidazolate framework-8/reduced graphene oxide (ZIF-8/RGO) hybrid aerogels are prepared by in situ anchoring ZIF-8 particles onto anisotropic RGO aerogel for efficient clean-up of spilled heavy crude oil. The solar-thermal ZIF-8/RGO hybrid aerogel with numerous vertical microchannels is efficient in decreasing viscosity and improving flowability of heavy crude oil because of the high solar light absorption and solar-thermal energy conversion capabilities of the RGO and the increased solar light diffuse reflection path and hydrophobicity of the aerogel by ZIF-8. Under 1-sun irradiation, the surface temperature of the aerogel reaches rapidly to 70 °C within 1 min. At the same time, the viscosity of the heavy crude oil falls quickly from 10⁵ to 10³ mPa s, and the maximum adsorption capacity of heavy crude oil reaches 112 g g⁻¹ within 9 min. Moreover, the hybrid aerogel exhibits satisfactory adsorption and cycling ability to various organic solvents and oily media. The excellent solar-thermal energy conversion and high adsorption capacities make the anisotropic aerogel promising for efficient clean-up of spilled heavy crude oil. © 2023 Elsevier Ltd. All rights reserved.