Recent developments in graphitic carbon nitride (g-C3N4) applications in micromotors

Polymeric graphitic carbon nitride (g-C3N4) is an emerging metal-free and visible-light-active photocatalyst with much interest in various fields such as environmental and biomedical fields. The creation of photocatalysts as micro nanomotors, which can perform reactions in micro nanoscales in complex environments has widened their utility in those fields. g-C3N4 can act as a photocatalyst and adsorbent, hence they are widely used in environmental remediation. This applicability opens up their extension in micro and nanomotor fields. This review focuses on the fundamentals and applications of g-C3N4 micromotors, especially in environmental remediation. Depending on the morphology of the supporting materials, the g-C3N4 micromotor undergoes selfelectrophoresis, self-diffusiophoresis, or bubble propulsion to move through the matrix under visible light irradiation. The motion of the particle simultaneously results in the generation of various reactive oxygen species and is utilized in the degradation of organic pollutants. The main advantage of g-C3N4 micromotors is that it does not require any toxic metal support and hence, can be applied in environmental remediation with minimal secondary pollution. However, most of the studies discussed in this review were carried out on a laboratory scale with limited solution volume. Therefore, a more comprehensive analysis is necessary for the implementation of the material in large-scale applications.