Composites of Co-Al hydrotalcites and carbon nanomaterials for photocatalytic H2 production

Hydrogen is considered one of the main energy sources for the near future. Numerous efforts are currently underway for the direct transformation of solar energy into H-2. Hydrotalcites are two-dimensional materials whose composition can be tuned relatively easily and, by themselves or in combination with other materials, are proving to be useful for the H-2 evolution reaction. In this work, composites of a Co-Al hydrotalcite with carbon spheres or nanotubes have been prepared. It has been shown that, in general, such composites improve H-2 production. The influence of the nature, structure, and characteristics of the different materials on the reaction has been studied, as well as the role of each component and its mechanism. In particular, proper integration of both components and improved textural properties, as is the case of the composite with carbon spheres, leads to a yield of 3820 mu mol H-2 g(-1) at 5 h, more than twice that obtained with hydrotalcite alone, in the presence of Ru (bpy)(3)Cl-2 as a photosensitizer and triethanolamine as an electron donor at 450 nm. The present methodology opens the door to the preparation of other composites for the improvement of the performance of photocatalytic systems for H-2 production.

Automated summary

Hydrogen is being extensively studied as one of the main future energy sources, and efforts are being made to directly convert solar energy into H-2. Hydrotalcites, a type of two-dimensional material, have shown potential for the H-2 evolution reaction when used alone or in combination with other materials. This study focused on preparing composites of Co-Al hydrotalcite with carbon spheres or nanotubes and found that such composites generally improve H-2 production. The nature, structure, and characteristics of the different materials, as well as the role and mechanism of each component, were investigated.