Using MoS₂ Nanomaterials to Generate or Remove Reactive Oxygen Species: A Review

Abstract

Molecular oxygen-derived free radicals and molecules that are highly reactive are generally referred to as reactive oxygen species (ROS). ROS are critical to the performance of redox-reaction-based environmental remediation approaches and at the same time are important players in the regulation of gene expression and cell signaling cascades. The irregular fluctuation of ROS can cause severe damage to the human body. Developing materials to modulate the amount of ROS is of great importance to environmental and biomedical sciences. Molybdenum disulfide (MoS 2 ) is a prototypical transition-metal dichalcogenide that has become a star in the family of 2D materials due to its unique physicochemical properties. The band gap, catalytic activity, and piezoelectric property of MoS 2 can be easily tuned by modifying its size, structure, phase, and doping with other functional materials. Some MoS 2 nanomaterials are emerging as promising candidates for generating or scavenging ROS. On the one hand, MoS 2 nanomaterials can effectively cause the generation of ROS via the photocatalytic reactions, photocytotoxic reactions, Fenton-like reactions, permonosulfate (PMS) activations, and piezoelectric effects. On the other hand, the exposed Mo 6+ / Mo 4+ redox couples render MoS 2 nanomaterials with antioxidant enzyme-like activity, through which ROS can be efficiently quenched. In this Review, recent advances in the applications of MoS 2 for modulating ROS are summarized. Current gaps as well as possible future directions in this field are discussed.

Edge Rich Ultrathin Layered MoS2 Nanostructures for Superior Visible Light Photocatalytic Activity

“…This enhancement of the photocatalytic performance and the percentage of dye degradation by MoS 2 nanostructures is mainly attributed to the formation of exposed edge sites on the sample’s surface. The compressive photodegradation of photocatalysts is influenced by many parameters including nanoscale structures, optical bandgap, edge sites, adsorption ability, sample morphology, etc. − …”

Mo3S132− Intercalated Layered Double Hydroxide: Highly Selective Removal of Heavy Metals and Simultaneous Reduction of Ag+ Ions to Metallic Ag0 Ribbons

“…TheM o 3 S 13 2À consists of S 2 2À ,S 2À ,a nd Mo 4+ ,i nw hich S 2 2À and Mo 4+ participate in the reduction of Ag + to Ag 0 .T he S 2 2À involves in the reduction to S 2À (E 0 (S 2 2À /S 2À ) = 0.34 V) [32] and oxidation to S 0 or SO 4 2À .T he E 0 (SO 4 2À /S 2 2À )of0.334 VorE 0 (S 0 /S 2 2À )of À0.20 Vvs. E 0 (Ag + /Ag 0 )o f0 .80 Vm eans apositive E value, inferring the thermodynamics is feasible.H owever,t he E 0 (MoO 4 2À /MoO 2 )of0.65 V [33] vs. E 0 (Ag + /Ag 0 )of0.80 Valso corresponds to ap ositive E value,s howing it is thermodynamically feasible. [34] Further,w ec an evaluate the feasibility of the proposed reactions (1-3) by estimating the approximate minimum E values (E min ).…”

Combating Drug-Resistant Bacteria Using Photothermally Active Nanomaterials: A Perspective Review

“…Semiconductors such as molybdenum disulfide (MoS 2 ) have attracted attention for their high band gap and photothermal properties ( Gupta et al, 2020 ). MoS 2 nanomaterials could result in ROS generation and ablation of bacteria with antioxidant enzyme-like activity ( Yu et al, 2021 ). Studies on chitosan modified MoS 2 coating loaded with Ag-NPs designed on titanium plates (CS/Ag/MoS 2 -Ti) exhibited both photodynamic and photothermal efficiency under 660 nm visible light, resulting in ROS production and bacteria killing ( Zhu et al, 2020 ).…”