Rare earth perovskite modified cobalt disulfide catalysts controlled by reaction solvent synthesis to form a p-n heterojunction

Abstract

The effect of reaction solvent on the hydrogen evolution activity of novel CoS2/FeLaO3-4(CS/FLO-4) p-n heterojunction photocatalysts, synthesized using the solvothermal method, was assessed. The highest activity under visible light irradiation was recorded for the CS/FLO-4 catalyst prepared in ethanol. In fact, after 5 h of reaction, the H2-yield of the ethanol composite (279.7 μmol) was found to be 5.2 and 150.2 times greater than that of CoS2 microspheres and FeLaO3 nanoparticles, respectively. Time-resolved fluorescence (TRF) and photoelectrochemical experiments confirmed the effectiveness of space charge separation in the ethanol catalyst, whereas linear sweep voltammetry results showed that this material is characterized by high current response. The direction of electron migration in the p-n type heterojunction (p-FeLaO3/n-CoS2) was found to be the same as that of photoexcited electron transfer (from the conduction band of CoS2 to the valence band of FeLaO3), which enhances the photocatalytic hydrogen evolution activity of the composite material. This work provides a feasible and simple strategy for the design and synthesis of FeLaO3-doped composite catalysts with high photocatalytic activity.