Z-Scheme MoS2/TiO2/graphene nanohybrid photocatalysts for visible light-induced degradation for highly efficient water disinfection and antibacterial activity

Abstract

We fabricated MoS₂/TiO₂/graphene (MTG) nanohybrids using a hydrothermal process in the preparation of heterostructure photocatalysts. The MTG nanohybrids exhibited high stability, large specific surface area, and visible light response. The heterostructure nanohybrids were effective in the visible-light photodegradation of tetracycline (TC), rhodamine B (RhB), and congo red (CR), as well as Pb(II) reduction. The nanohybrids exhibited a photocatalytic TC removal capability of 94.5% with 60 min of visible light irradiation. Suppressing the recombination of photoexcited electron–hole pairs enhanced the removal of environmental pollutants. The MTG nanohybrids also displayed photocatalytic reduction of Pb(II), approximately 10–15 times that of bare MoS₂ and TiO₂ samples. The nanohybrids also showed efficient photocatalytic antibacterial performance, killing 99.9% of E. coli in 10 min, thus demonstrating environmental friendliness in water disinfection. The results clearly demonstrated promising nanohybrids for the photocatalytic removal of a wide variety of contaminants, such as hazardous organic chemicals, heavy metals, and pathogenic microbes, under visible light irradiation.