Combining the Photocatalysis and Absorption Properties of Core-Shell Cu-BTC@TiO2 Microspheres: Highly Efficient Desulfurization of Thiophenic Compounds from Fuel

Abstract

A core-shell Cu-benzene-1,3,5-tricarboxylic acid (Cu-BTC)@TiO2 was successfully synthesized for photocatalysis-assisted adsorptive desulfurization to improve adsorptive desulfurization (ADS) performance. Under ultraviolet (UV) light irradiation, the TiO2 shell on the surface of Cu-BTC achieved photocatalytic oxidation of thiophenic S-compounds, and the Cu-BTC core adsorbed the oxidation products (sulfoxides and sulfones). The photocatalyst and adsorbent were combined using a distinct core-shell structure. The morphology and structure of the fabricated Cu-BTC@TiO2 microspheres were verified by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, X-ray powder diffraction, nitrogen adsorption-desorption and X-ray photoelectron spectroscopy analyses. A potential formation mechanism of Cu-BTC@TiO2 is proposed based on complementary experiments. The sulfur removal efficiency of the microspheres was evaluated by selective adsorption of benzothiophene (BT) and dibenzothiophene (DBT) from a model fuel with a sulfur concentration of 1000 ppmw. Within a reaction time of 20 min, the BT and DBT conversion reached 86% and 95%, respectively, and achieved ADS capacities of 63.76 and 59.39 mg/g, respectively. The BT conversion and DBT conversion obtained using Cu-BTC@TiO2 was 6.5 and 4.6 times higher, respectively, than that obtained using Cu-BTC. A desulfurization mechanism was proposed, the interaction between thiophenic sulfur compounds and Cu-BTC@TiO2 microspheres was discussed, and the kinetic behavior was analyzed.

Desulfurization through Photocatalytic Oxidation: A Critical Review

“…Therefore, researchers began to use carrier materials with high surface area to fix and disperse TiO 2 nanoparticles. Currently, carbon materials (carbon nanotubes, [47] graphene, [86] bamboo charcoal [96] ), porous silicon dioxide (MCM‐41), [51] porous glass, [97] and metal‐organic frameworks (MOFs) [98] have been reported as the supporting matrix for PODS [99,100] …”

“…Currently, carbon materials (carbon nanotubes, [47] graphene, [86] bamboo charcoal [96] ), porous silicon dioxide (MCM-41), [51] porous glass, [97] and metal-organic frameworks (MOFs) [98] have been reported as the supporting matrix for PODS. [99,100] Carbon nanomaterials such as MWNTs, graphene, carbon dots, and carbon nanosheets have been employed as ideal carrier materials for photocatalysis due to the advantages of unique morphology, strong adsorption ability, good conductivity, and high chemical stability. [47] Particularly, due to the one/ two-dimensional structure and special electronic property, both MWNTs and graphene can pave a "highspeed way" for the transport of excited photogenerated electrons, and therefore inhibit the recombination process.…”

Application of TiO2-Cu Composites in Photocatalytic Degradation Different Pollutants and Hydrogen Production

“…Researchers proved that, if copper nanoparticles are present in a higher amount, CuO crystallization can take place [32]. An interesting finding is that the combination of photocatalysis and adsorption can accomplish deep desulfurization [33].…”

Generating oxygen vacancies in Cu 2+ ‐doped TiO 2 hollow spheres for enhanced photocatalytic activity and antimicrobial activity

“…Therefore, it is extremely appealing to develop the modified TiO 2 photocatalysts that combine low‐cost and excellent energy conversion efficiency. In addition, although some papers about Cu‐doped TiO 2 have been published in the literature [20], there has been little research on the photocatalytic mechanism of Cu‐doped TiO 2 .…”