Formulation of heterometallic ZIF-8@Cu/Ni/ZnO@CNTs heterostructure photocatalyst for Ultra-Deep desulphurization of coal and fuels

Developing efficient methods for deep desulphurization of commercial fuel is critical because of the requirements to limit sulphur concentrations below 10 ppm. Among various methods, recently photocatalytic oxidative desulphurization (PODS) has attracted great attention as it does not require high temperature and pressure. Herein, we report a novel heterostructure h-ZIF-8@Cu/Ni/ZnO@CNTs, having heterometallic ZIF-8 (h-ZIF-8) coated on Cu/Ni/ZnO (h-ZIF-8@Cu/Ni/ZnO), supported over carbon nanotubes (CNTs) sponge for selective PODS of both coal and fuel. The Cu/Ni/ZnO-based ternary hybrid metal oxide was first stabilized on a CNTs sponge followed by a surface reaction of metal particles with 2-methyl imidazole to in-situ form h-ZIF-8 shell on the surface of Cu/Ni/ZnO. The resulting h-ZIF-8@Cu/Ni/ZnO@CNTs exhibited high surface area (1283.47 m2/ g), meso/microporous backbone, narrow bandgap (2.52 eV), and a large number of available active sites. Owing to these characteristics, the h-ZIF-8@Cu/Ni/ZnO@CNTs exhibited excellent photocatalytic response for the removal of organic sulphur with a removal rate of 0.76 Kg m-3 day-1 compared to control ZIF-8@ZnO@CNTs (0.4 Kg m- 3 day -1). The removal rate was further enhanced to 3.3 Kg m-3 day -1 for dibenzothiophene, con-firming the higher PODS potential of the designed photocatalyst for refractory organic sulphur. In summary, the h-ZIF-8@Cu/Ni/ZnO@CNTs possess promising characteristics to be applied for the desulphurization of com-mercial fuels.

Automated summary

Developing efficient methods for deep desulphurization of commercial fuel is critical. Photocatalytic oxidative desulphurization (PODS) is a promising method that has gained attention due to its low temperature and pressure requirements. In this study, a novel heterostructure h-ZIF-8@Cu/Ni/ZnO@CNTs photocatalyst was developed for selective PODS of coal and fuel.