Aminated silicon dioxide enriching iron-containing polyoxometalate catalyst confined in CdS for efficient H2 evolution

Abstract

The rational design of an artificial system that mimics natural photosynthesis for H2 evolution remains a substantial yet engaging challenge. Efficient light absorption, charge separation and associated surface reactions are crucial aspects of semiconductor photocatalytic system for efficient water splitting. Herein, a catalyst assembly of p-SiO2-NH3-Fe11POM@CdS was constructed by partially etched SiO2-NH2 coating CdS (p-SiO2-NH2@CdS) bound iron-based polyoxometalate (Fe11POM) in the interstitial space. In the hybrid catalyst, Fe11POM acts as catalyst and p-SiO2-NH2@CdS as light-harvesting material as well as Fe11POM enrichment center, respectively. The p-SiO2-NH3-Fe11POM@CdS catalyst exhibits a high H2 evolution activity of 23.1 mmol g−1 h−1 with turnover number (TON) of 3225 and apparent quantum efficiency (AQE) of 71% under 420 nm LED illumination. The electrons transfer from p-SiO2-NH2@CdS to Fe11POM, affording electrons accumulated in Fe11POM for H2 evolution. Our strategy of building hybrid photocatalyst will provide a new way to construct efficient catalyst assembly for water splitting.