Influence of pre-oxidation, versus post-oxidation of carbon nanohorns in TiO<inf>2</inf> nanohybrid for enhanced photocatalytic hydrogen production

Carbon nanohorns were prepared using Arc discharge method in an open air at stationary cathode. Nanohybrids of carbon nanohorns/titania were synthesized by wet impregnation method followed by thermal oxidation in air at 520 °C for 30 min. Alternatively, pre-oxidized carbon nanohorns were prepared at the same conditions to examine any change in surface properties. Nanohybrids were subjected to characterization for its structure, morphology, optical properties and life-time of photogenerated electrons and holes. The photocatalytic performance of the two nanohybrids activated by solar light confirmed that pre-oxidized catalyst showed superior performance followed by post-oxidised and pristine catalyst. Hence, present study delineates the benefits of pre-oxidation process that generated nanowindows morphology on carbon surface that facilitated increased generation, effective utilization and minimizes the recombination of electron-hole pairs in-turn triggered enhanced hydrogen production.