In situ preparation of a novel organo-inorganic 6, 13-pentacenequinone–TiO2 coupled semiconductor nanosystem: a new visible light active photocatalyst for hydrogen generation. Issue 8 (22nd January 2015) - Pandit, Vikram
Abstract : We investigated a new organo-inorganic hybrid semiconductor nanosystem (6, 13-pentacenequinone–TiO2 ) for hydrogen production. Abstract : Previous studies related to the synthesis of stable UV-visible light active photocatalysts for hydrogen generation have been limited to inorganic semiconductors and their nano- and hetero-structures. We demonstrate here the use of an organo-inorganic 6, 13-pentacenequinone (PQ)–TiO2 coupled semiconductor nanosystem as an efficient photocatalyst active in visible light for the production of hydrogen. Anatase TiO2 nanoparticles (3–5 nm) were uniformly decorated on thin sheets of monoclinic PQ by an in situ solvothermal method. These as-prepared PQ–TiO2 coupled semiconductor nanosystems had a band gap in the range 2.7–2.8 eV. The strong emission at 590 nm can be attributed to the transfer of electrons from the LUMO energy level of TiO2 to combine with the holes present in the HOMO level of PQ. This electron–hole recombination makes availability of electrons and holes in LUMO of PQ and HOMO of TiO2, respectively. This hybrid semiconductor coupled nanosystem resulted in a rate of hydrogen evolution of 36 456 μmol h −1 g −1 from H2 S under UV-visible light; this is four times higher than the rate obtained with TiO2 in earlier reports of UV-visible light active photocatalysts. These results open up a new path to explore inorganic systems coupled with PQ as new photoactive hybrid catalysts in a number of chemical and physicochemical processes.