FeS and Ni-doped FeS nanomaterials as bifunctional photocatalysts and gas sensors

Abstract

In this work, pristine Iron sulphide (FeS) and nickel-doped Iron sulphide (Ni-FeS) nanomaterials were efficiently hydrothermally synthesized. The synthesized nanomaterial was scientifically investigated by various analytical techniques like FTIR, UV–visible spectroscopy, XRD, SEM-EDAX, and HR-TEM-SAED. The study reveals that synthesized FeS is crystalline hexagonal (troilite phase) with an average crystallite size of 17.21 nm. Ni-FeS crystal structure remains unchanged, but XRD peaks become broader compared to FeS due to Ni. The HR-TEM result confirms the particle sizes of FeS and Ni-FeS as 50–130 nm and 24 nm, respectively. Surface morphology of FeS and Ni-FeS appeared as a uniform distribution and agglomeration of particles, depicted by SEM. EDAX analysis confirms elemental composition. UV–visible and Tauc plot studies give band gap energies of 2.03 and 1.71 eV for FeS and Ni-FeS, respectively. The photodegradation of malachite green (MG) dye was scientifically evaluated to assess the photocatalytic capacity of both FeS and Ni-FeS. 90.05 % dye degradation was achieved by Ni-FeS, as compared to FeS 88.01 % under identical conditions. The gas sensing investigation studies give a good response and recovery time for H₂S gas at 120 °C. All these results highlight the benefits of Ni-FeS and FeS as a promising, stable, and efficient material.