Carbon nitride coupled with carbon nanohorns for improved photocatalytic hydrogen production and dyes degradation

In the present study we attempted to develop photoactive nanocomposites via the facile coupling of carbon nitride (CN) with single walled carbon nanohorns (CNHs). Photocatalytic activity was evaluated for the degradation of Rhodamine B (RhB) and the production of H2. The CNHs content noticeably affected the photoactivity of the nanocomposites and the best performing material exhibited a 3-fold increase in photocatalytic H2 production compared to pristine CN using 1 wt% Pt as co-catalyst. A systematic study was undertaken to explain the mechanistic aspects of the photo-reaction process. The active species responsible for the photodegradation of RhB were identified using reference reactions. Such species were further studied using in-situ spin-trap EPR experiments. Photoluminescence and time-resolved fluorescence decay kinetics suggested faster transfer of photogenerated electron/hole pairs resulting in reduced charge recombination phenomena in the nanocomposites. The combined photocatalytic application and characterization of the prepared materials revealed that the promotion of the redox reactions in based on improvements on the charge separation efficiency.