All-in-one synthesis of mesoporous silicon nanosheets from natural clay and their applicability to hydrogen evolution

A cost-efficient technique for turning clay minerals into active photocatalysts could benefit solar-based generation of hydrogen fuel. Light-sensitive, two-dimensional (2D) silicon nanosheets have been targeted as catalysts for photoelectrochemical water splitting because their unique geometry enables ample interaction with water molecules. However, most synthetic routes to 2D silicon nanosheets require specialized reagents and conditions. Soojin Park and co-workers in South Korea have developed a strategy based on montmorillonite clay, an abundant mineral that contains 2D layers of silicon, oxygen and aluminum atoms. They found that reacting molten sodium chloride salts with the clay simultaneously exfoliated the natural 2D layers and reduced their chemical structure to produce ultrathin silicon nanosheets with a narrow size distribution. Preliminary tests revealed the 2D photocatalyst generated substantial quantities of hydrogen gas from a water–methanol mixture with a platinum co-catalyst.