Covalent grafting of molecular catalysts on C3NxHy as robust, efficient and well-defined photocatalysts for solar fuel synthesis. Issue 32 (31st July 2020) - Windle, Christopher D.
Abstract : A nickel bis-aminothiophenol catalyst grafted onto a 2D carbon-nitride photocatalytically produces H2 beyond 8 days with turnover numbers reaching 1360. Abstract : The covalent attachment of molecules to 2D materials is an emerging area as strong covalent chemistry offers new hybrid properties and greater mechanical stability compared with nanoparticles. A nickel bis-aminothiophenol catalyst was grafted onto a range of 2D carbon nitrides (C3 N x H y ) to form noble metal-free photocatalysts for H2 production. The hybrids produce H2 beyond 8 days with turnover numbers reaching 1360 based on nickel, a more than 3 fold higher durability than reported molecular catalyst-carbon nitride mixtures, and under longer wavelengths (>475 nm). Time-resolved spectroscopy reveals sub-microsecond electron transfer to the grafted catalyst, six orders of magnitude faster compared with similar reports of non-grafted catalysts. The photoelectrons on the catalyst have a ca. 1000 times longer half-time (7 ms) compared with bare carbon nitride (10 μs). The grafting strategy operates across a range of molecular catalyst-carbon nitride combinations, thus paving the way for robust efficient photocatalysts based on low-cost tunable components.