Facile fabrication of new SiO₂@dopamine hybrid aerogels with enhanced desulfurization adsorption capacity

Tetraethoxysilane (TEOS) was easily hybridized with dopamine to prepare a series of SiO₂@dopamine (SiO₂@DA-n, where n represents the molar ratio of TEOS to DA in reaction precursors) hybrid aerogels using sol-gel method at room temperature and drying under atmospheric pressure, where the preparation process is relatively simple, and dopamine (DA) can be obtained from various biomaterials having good biocompatibility and renewability. All SiO₂@DA-n hybrid aerogels exhibited the markedly greater adsorption uptakes for thiophene compared with the pure SiO₂ aerogel, among them, the SiO₂@DA-50 conducted the best, having a breakthrough sorption uptake for thiophene of 7.89 mg S/g ads . Moreover, SiO₂@DA-50 had a good resisting ability for competitive adsorption of aromatic hydrocarbons, whose breakthrough sorption uptake for thiophene could be kept to 6.05 mg S/g ads , in the presence of 20 wt% benzene in the model gasoline. The atmospheric pressure heat treatment regeneration method could recover 100% of the breakthrough adsorption uptake for thiophene of spent SiO₂@DA-50. The case is attributed to that the -NH 2 groups and benzene ring on the surface of SiO₂@DA-n hybrid aerogels could act as the adsorption active centers of hydrogen bonding and π-π stacking for thiophenic compounds, respectively. SiO₂@DA-50 hybrid aerogels is a promising desulfurization adsorbent.