Visible light active photocatalysis on block copolymer induced strings of ZnO nanoparticles doped with carbon

We report a facile route for the fabrication of a unique configuration of carbon-doped strings of ZnO nanoparticles obtained by subjecting solvent vapor annealing followed by direct carbonization to reconstructed block copolymer inverse micelle arrays. The dual role of a carbon (C) moiety has been exploited in significantly enhancing the catalytic performance of C–ZnO nanohybrids under the illumination of visible light. The first role is to create a new energy level above the valence band of ZnO and the other is to act as a channel by which recombination of the excitons is effectively suppressed. The enhanced visible light active photocatalytic efficiency and recyclability of C–ZnO was demonstrated in terms of degradation of a target dye (p-nitrophenol) molecule. Photoelectrochemical water splitting was also performed using C–ZnO on ITO as the working electrode. A significant enhancement in the photocurrent density was obtained for C–ZnO compared with bare ZnO. A plausible mechanism to support the enhanced visible light activity of C–ZnO was proposed.