Bubble-Propelled Tubular Heterostructural Micromotors Fabricated by Interfacial Superassembly for Efficient Photo-Fenton Removal of Ciprofloxacin

Abstract

The presence of organic pollutants in the environment poses a significant threat to ecosystems and human health. Although diverse micromotors have been designed to enhance the performance of environmental remediation, complicated fabrication processes and expensive materials remain a challenge. In this work, a bubble-propelled C3N4@CuS-MnO2 microtubular motor (C3N4@CuS-MnO2 MTs) was fabricated by an interfacial superassembly strategy for efficient photo-Fenton removal of ciprofloxacin. Rod-shaped precursors were first prepared by the interfacial self-assembly between melamine and cyanuric acid under hydrothermal conditions. Pyrolysis of the precursor center was used to synthesize ultrathin C3N4 microtubes (C3N4 MT) through calcination. The C3N4 MT served as the framework of the micromotor for sequential in-situ growth of CuS and MnO2 nanosheets to form a tubular heterostructure. The C3N4@CuS-MnO2 MTs catalyze the decomposition of H2O2 to inject O2 bubble, producing a powerful thrust to drive the motion of micromotors. The bubble-propelled motion of C3N4@CuS-MnO2 MTs induces enhanced fluid mixing to promote mass transfer and interaction between catalysts and pollutants. Integrating the synergistic effect of photo-Fenton catalytic process and autonomous motion, C3N4@CuS-MnO2 MTs as an on-the-fly cleaning platform can produce a large amount of reactive oxygen species, achieving efficient degradation of ciprofloxacin. Overall, this work provides a new strategy for the design of bubble-propelled heterostructural micromotor with broad application potential for environmental remediation.

Keywords: bubble-propulsion, tubular heterostructural micromotors, photo-Fenton processes, interfacial superassembly, removal of ciprofloxacin