Synthesized transparent CQD–PVA composite films performed stable UV-A blocking, even after exposure to UV light for several days and elevated temperature.

For the first time Knoevenagel condensation has been catalyzed by elemental copper with unexpected activity and excellent isolated yields. Inexpensive, widely available copper powder was used to catalyze the condensation of cyanoacetate and benzaldehyde under mild conditions. To ensure general applicability, a wide variety of different substrates was successfully reacted.