Light-harvesting carbon allotropes platforms for photocatalytic hydrogen production from water

Decorating carbon allotropes with photoactive materials has been recently studied for solar light conversion in energy and environmental fields. Recently we have reported the synthesis and surface characterization of multi-walled carbon nanotubes (CNT), CdS, and metal catalyst (M) hybrids (CdS/CNT/M), and their novel application to photocatalytic hydrogen production under visible light (l > 400 nm) in the presence of electron donor (Energy Environ. Sci. 4 (2011) 685). In the binary hybrids between CNT and CdS (CdS/CNT) the CNT annealed at 500 °C (h-CNT) has the larger amount of hydrogen production than crude (c-CNT) or acid-treated CNT (a-CNT) due to highly improved purity and suitable work function. When hybridized with CdS and M, however, a-CNT has the largest amount of hydrogen production (a-CNT > h-CNT > c-CNT) even though all the CNTs have the similar functional groups for binding metal catalyst on their surfaces. As an ongoing work, we have employed five different carbon allotropes and decorated them with CdSe nanoparticles in order to investigate the key factors in determining the overall photocatalytic efficiency. In this presentation, the surface characterization of and hydrogen production from the photocatalyst hybrids and the relationship between the two will be discussed.