Carbon-ZnO core-shell nanospheres: Facile fabrication and application in the visible-light photocatalytic decomposition of organic pollutant dyes

We developed a simple thermolysis method for fabricating effective photocatalysts for the decomposition of organic pollutants under sunlight. Zinc oxide-deposited carbon spheres (ZDCS) were prepared via a one-pot process in a solvent- and catalyst-free environment. The ZDCS composite exhibited a strong light absorption band across the whole visible range, a very good dispersion concentration (1.84 mg/mL) in organic solvents without the need for surfactants, ionic liquids, or stabilizers, and a high electrical conductivity (∼1300 S/m). These materials were shown to be useful for decomposing organic pollutants under sunlight. The reaction time (105 min), degradation percentage (98.2%), and recycling performance suggested that ZDCS act as an excellent photocatalyst under visible light illumination for the decomposition of methylene blue. The enhanced physicochemical properties of the ZDCS are due to the covalent interaction between the carbon core and ZnO outer layer, which increases the lifetime of photo-generated charge carriers.