Highly efficient visible-light-driven photocatalytic disinfection of flowing bioaerosol using mono/multilayer MXene based catalyst

In this study, two kinds of 2D materials (nanoscale mono/multi-layer MXene) were prepared, and a new visible-light-driven photocatalyst MXene@In2S3 was synthesized by one-step hydrothermal preparation. Due to the better conductivity and larger specific surface area of the monolayer MXene, monolayer MXene@In2S3 exhibited greater transient response photocurrent and smaller interfacial charge transfer resistance than those of multilayer MXene@In2S3 under visible light irradiation. All these indicated that the synergistic effect of type-II heterojunction and TiO2/Ti(3)C(2)Tx interface provided a shorter and more direct channel for electron transfer between In2S3, TiO2 and MXene. When bioaerosol was sterilized by dynamic continuous flow photocatalytic reactor carrying monolayer MXene@In2S3, it can reach 1.55 lg in 9.6 s (multilayer MXene@In2S3 was 1.19 lg). Biological particles of different particle sizes were effectively removed from the bioaerosol. The excellent photocatalytic disinfection performance was due to the oxidation substances (holes, center dot O-2(-) and center dot OH) produced by the photocatalyst under visible light irradiation. Microbial cell membrane permeability was disrupted, causing irreversible physical damage that will ultimately lead to sustained inactivation within 16 h. Due to the unique physical and chemical properties of the two-dimensional material MXene, it has scope for further exploration in the field of disinfection and air purification.

Automated summary

In this study, two-dimensional materials (nanoscale mono/multi-layer MXene) were prepared and a visible-light-driven photocatalyst MXene@In2S3 was synthesized. The monolayer MXene@In2S3 exhibited better photocurrent response and charge transfer resistance than the multilayer MXene@In2S3 under visible light irradiation. The excellent photocatalytic disinfection performance of MXene@In2S3 was attributed to the oxidation substances produced under visible light irradiation, causing irreversible physical damage to microbial cells and resulting in sustained inactivation.