Triggering inert desert sand toward a low-cost and efficient cocatalyst for photocatalytic hydrogen evolution reactions

Abstract

Developing active and stable cocatalysts is highly crucial for realizing efficient photocatalytic water splitting to produce green H₂. However, most cocatalysts developed thus far have been prepared through tedious processes with the use of high-purity chemical reagents and, if necessary, expensive artificially synthesized supports. Herein, desert sand (DS), which is generally considered as an abundant but nuisance material, is converted into a highly active and stable cocatalyst for the photocatalytic H₂ evolution reaction (HER) via the simple low-temperature vapor-phase phosphidation process. During phosphidation, the endogenous Fe species within the DS are transformed into tiny FeP nanoparticles that are firmly embedded on the surface of the DS substrate with high dispersion, providing highly stable and active sites for the HER. Consequently, the as-fabricated FeP/DS cocatalyst exhibits superior activity and stability for the photocatalytic HER in both dye-sensitized systems and when combined with CdS under visible-light irradiation. This strategy of triggering transition metals from naturally abundant materials into high-performance supported cocatalysts opens a new pathway for the development of cost-effective photocatalysts/photocatalytic systems for sustainable solar H₂ production.