Bio-inspired photocatalytic desulfurization performance of TiO2 wrapped spherical metallophthalocyanine

The development of stable and efficient photocatalysts for the oxidative degradation of dibenzothiophene(DBT) in fuels remains a major challenge. Herein, a novel spherical binuclear metallophthalocyanine containing methoxy substituents Mn 2 Pc 2 (EP) 4 was self-assembled on TiO 2 via planar conjugated-ligand π-interaction to prepare Mn 2 Pc 2 (EP) 4 /TiO 2 photocatalysts using a facilely “in suit” hydrothermal method. The red-shifted in the UV absorption bands of the Mn 2 Pc 2 (EP) 4 /TiO 2 composites indicated a strong π-interaction between the composite materials. The Mn 2 Pc 2 (EP) 4 /TiO 2 catalysts exhibited high stability and oxidative desulfurization performance towards DBT in a model oil containing n-octane. The catalytic efficiency of the Mn 2 Pc 2 (EP) 4 /TiO 2 composite (98.85 %) was approximately 2.2 times higher than that of TiO 2 (44.97 %). The results verified that Mn 2 Pc 2 (EP) 4 improved the visible-light photocatalytic activity and enhanced the oxidative desulfurization activity of TiO 2. The photocatalytic efficiency of the Mn 2 Pc 2 (EP) 4 /TiO 2 catalyst remained at 92 % for DBT after 5 reaction cycles. Thus, the samples exhibited excellent recoverability and stability compared to that of TiO 2 . Mechanistic studies revealed that the ⁎ O 2 -[Mn 2 Pc 2 (EP) 4 ] + /TiO 2 (e − ) species, which were the main active intermediate via the π-interaction self-assembling of Mn 2 Pc 2 (EP) 4 , effectively improved the photocatalytic oxidation degradation of DBT. This study demonstrates the potential of Mn 2 Pc 2 (EP) 4 /TiO 2 catalysts for developing environmentally friendly and efficient visible-light-driven desulfurization technology.