Light-Triggered Catalytic Performance Enhancement Using Magnetic Nanomotor Ensembles

Abstract

<jats:p>Micro/nanomachines have attracted extensive attention in the biomedical and environmental fields for realizing functionalities at small scales. However, they have been rarely investigated as active nanocatalysts. Heterogeneous nanocatalysts have exceptional reusability and recyclability, and integration with magnetic materials enables their recovery with minimum loss. Herein, we propose a model active nanocatalyst using magnetic nanomotor ensembles (MNEs) that can degrade contaminants in an aqueous solution with high catalytic performance. MNEs composed of a magnetite core coated with gold nanoparticles as the nanocatalyst can rotate under the action of a programmable external field and carry out rapid reduction of 4-nitrophenol (4-NP). The hydrogen bubbles generated in the catalytic reaction provide random perturbations for the MNEs to travel in the reaction solution, resulting in uniform processing. The reduction can be further boosted by irradiation with near-infrared (NIR) light. Magnetic field induces the rotation of the MNEs and provides microstirring in the catalysis. Light enhances the catalytic activity <jats:italic>via</jats:italic> the photothermal effect. These MNEs are also capable of moving to the targeted region through the application of a programmable magnetic field and then process the contaminant in the targeted region. We expect that such magnetic MNEs may help better in applying active heterogeneous nanocatalysts with magnetic field and light-enhanced performance in industrial applications due to their advantages of low material cost and short reaction time.</jats:p>

Tethered and Untethered 3D Microactuators Fabricated by Two-Photon Polymerization: A Review

“…The abovementioned advantages make magnetic actuation the preferred strategy for driving microactuators [ 58 ]. A large amount of exploratory work has been done and continues to be carried forward [ 42 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 ]. The marriage of the magnetic driving method and TPP, which features precise and designable 3D shapes for microstructures, provides a new platform for the research of magnetron microactuators.…”

Magnetically Driven Micro and Nanorobots

“…Additionally, magnetic fields can be used to accelerate reaction kinetics or recognition efficiency due to the robust dynamic intermixing (i.e., magnetic stirring function) and to retrieve the nano/microrobots once the cleaning procedure has been finalized. 400 Eventually, the cleaning agents can be reused or recycled if their constituent components have remained unaltered. The treatment of six representative pollutants using miniaturized magnetic motors is summarized in Figure 20 .…”

Vector-Controlled Wheel-Like Magnetic Swarms With Multimodal Locomotion and Reconfigurable Capabilities

“…Inspired by the behavior of natural swarms, various dynamic patterns, such as liquid ( Xie et al, 2019 ), chain ( Martinez-Pedrero et al, 2015 ), ribbon ( Yu et al, 2018b ), vortex ( Yu et al, 2018a ; Kokot and Snezkho, 2018 ), and ellipse ( Yu J. et al, 2021 ; Zhang et al, 2021 ), have been reproduced by artificial swarming strategies. The design of these sophisticated swarming systems could potentially revolutionize the environmental, chemical and medical fields, such as pollution degradation ( Ji et al, 2020 ), heterogeneous catalysis ( Wang et al, 2019 ), active drug delivery ( Servant et al, 2015 ) and localized treatment of tumor ( Wang et al, 2018 ). Complex biological environments are extremely relevant to the applications of microswarms, which are expected to travel in blood vessels ( Wang et al, 2021 ; Yu et al, 2022 ), urinary system ( Hortelao et al, 2021 ), and microfluidic chips ( Soto and Chrostowski, 2018 ; Zhao et al, 2021 ).…”