The present finding deals with a simple and low-cost fabrication of surface-passivated, brightly fluorescent zincoxide- decorated, red-emitting excitation-independent ultrafluorescent CDs, denoted as “CZnO-Dots”. Surface doping of zinc oxide significantly improved the quantum yield by up to ∼72%, and these brightly fluorescent red-emitting CZnO-Dots have been employed for the aqueous-phase photoreduction of 100 ppm hexavalent chromium(VI) to trivalent chromium(III) under the influence of sunlight irradiation. The overall utility of the prepared CZnO-Dots can be ascertained by their recyclability over seven cycles.
The doped CD with inorganic salts can apparently form a newer platform among the existing class of fluorescent optical materials such as QDs and organic dyes. The doped-soluble CD with a higher quantum yield value can provide solutions to many newer emerging and existing problems. The aqueous solutions of red-emitting brightly fluorescent CZnO-Dots with excellent photostability could compete with the already existing commercially available QDs and organic dyes for similar types of applications. Such as related to the deeper penetration ability of the fluorescent probe could directly relate the excellence of instructive image analysis. Beyond these, brightly fluorescent CZnO-Dots do have the potential for use as an excellent photocatalytic material because of their working window, which is situated in the lower wavelength region. Interestingly, further studies could reveal a vast prospective future of these solublebrightly fluorescent CZnO-Dots in the field of photocatalysis and water treatment.