Photocatalytic Pt/Ag3VO4 micromotors with inherent sensing capabilities for corroding environments

Autonomous self-propelled micromachines based on semiconductors are at the forefront of environmen-tal pollutants degradation research to palliate the effects of the contamination arising from the constant manufacturing of new products. Nonetheless, testing these micromotors with real-life products is almost an unexplored field, limiting the degradation of pollutants to single-component aqueous solutions or sus-pensions at the laboratory scale, which hinders the translation of these micromachines into useful sys-tems. Herein, Ag3VO4 has been devised as a micromotor by an asymmetric deposition of a thin layer of Pt, giving rise to Pt/Ag3VO4 micromotors (Janus particle). Their motion capabilities have been demon-strated under UV light in fuel-free conditions. Their photocatalytic performance at laboratory scale has been confirmed for the degradation of Rhodamine B while, as a first approximation of a real-life applica-tion, the degradation of an energy drink has also been tested. During this latter exploration, the Pt/Ag3VO4 micromotors were corroded by the citric acid present in the pollutant, releasing Ag nanoparticles into the media. As a proof of concept, the position of the generated Ag nanoparticles' surface plasmon resonance absorption maximum has been demonstrated to show a dependency on the concentration of citric acid.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Semiconductor-based autonomous self-propelled micromachines are at the forefront of research on environmental pollutant degradation, aiming to alleviate the contamination effects caused by the constant production of new products. However, testing these micromotors with real-life products is largely unexplored, limiting the degradation of pollutants to laboratory-scale single-component aqueous solutions or suspensions, hindering the translation of these micromachines into practical systems.