Composition-dependent band structure parameters and band-gap bowing effect in a caesium lead mixed halide system: a cyclic voltammetry investigation.

Cyclic voltammetry techniques have been employed to study the effect of halide substitution on the band edge parameters and band gap bowing effect in the case of CsPbX [X = I, Br, Cl] perovskite nanocrystals (PNCs). A series of compositions, CsPbI, CsPb(I-Br), CsPbBr, CsPb(Br-Cl) and CsPbCl, have been prepared by a hot injection method. From powder XRD and HR-TEM analysis, the formation of a highly crystalline, cubic phase of the perovskite having size in the range from 7-20 nm has been confirmed.

Covalent Organic Framework Catalyzed Amide Synthesis Directly from Alcohol Under Red Light Excitation.

The dehydrogenative coupling of alcohols and amines to form amide bonds is typically catalysed by homogeneous transition metal catalysts at high temperatures ranging from 130-140 °C. In our pursuit of an efficient and recyclable photocatalyst capable of conducting this transformation at room temperature, we report herein a COF-mediated dehydrogenative synthesis. The TTT-DHTD COF was strategically designed to incorporate a high density of functional units, specifically dithiophenedione, to trap photogenerated electrons and effectively facilitate hydrogen atom abstraction reactions.