Organic Semiconductor/Carbon Dot Composites for Highly Efficient Hydrogen and Hydrogen Peroxide Coproduction from Water Photosplitting

Abstract

Coproduction of hydrogen (H₂) and hydrogen peroxide (H₂O₂) from water splitting is one of the most promising ways to alleviate the energy crisis and environmental pollution. Here, we first show the synthesis and photocatalytic property of an organic semiconductor (DAnTMS compound) from 9,10-dibromoanthracene and trimethylsilylacetylene. Then, a metal-free photocatalyst of a DAnTMS/carbon dot (DAnTMS/CD) composite was designed and fabricated, which achieved the efficient photocatalytic production of H₂ and H₂O₂ without usage of any organic solvents and sacrificial agents. Under visible light, the DAnTMS/CD composite could produce H₂O₂ with a maximum rate of 396.7 μmol g^-1 h^-1 and H₂ with a maximum rate of 265.0 μmol g^-1 h^-1 in pure water. Transient photovoltage tests showed that CDs changed the interfacial electron transfer kinetics and served as the active site for highly efficient H₂ evolution. This work provided a deep insight into the function of CDs in regulating the catalytic property of organic photocatalysts.