Green emitter copper clusters as highly efficient and reusable visible degradation photocatalysts.

Green emitter copper clusters (CuCLs) with a size of ≈1.5 nm can be used as very efficient and recyclable photocatalysts for the degradation of methylene blue, both in solution and supported onto glass surface showing a photocatalytic efficiency larger than that found with common semiconductors. These results open a new important potential way to overcome major difficulties found in the photocatalysis field with the common semiconductors.