Highly luminescent and catalytically active suprastructures of magic-sized semiconductor nanoclusters

Abstract

Metal chalcogenide magic-sized nanoclusters have shown intriguing photophysical and chemical properties, yet ambient instability has hampered their extensive applications. Here we explore the periodic assembly of these nanoscale building blocks through organic linkers to overcome such limitations and further boost their properties. We designed a diamine-based heat-up self-assembly process to assemble Mn2+:(CdSe)(13) and Mn2+:(ZnSe)(13) magic-sized nanoclusters into three- and two-dimensional suprastructures, respectively, obtaining enhanced stability and solid-state photoluminescence quantum yields (from <1% for monoamine-based systems to similar to 72% for diamine-based suprastructures). We also exploited the atomic-level miscibility of Cd and Zn to synthesize Mn2+:(Cd1-xZnxSe)(13) alloy suprastructures with tunable metal synergy: Mn2+:(Cd0.5Zn0.5Se)(13) suprastructures demonstrated high catalytic activity (turnover number, 17,964 per cluster in 6 h; turnover frequency, 2,994 per cluster per hour) for converting CO2 to organic cyclic carbonates under mild reaction conditions. The enhanced stability, photoluminescence and catalytic activity through combined cluster-assembly and metal synergy advance the usability of inorganic semiconductor nanoclusters.