Synergy of a CuO/C 3 N 4 interface and CuO nanoparticles in the ethynylation of formaldehyde for 1,4-butynediol synthesis.

Catalysts made of CuO/Bi 2 O 3 nanoparticles supported on g-C 3 N 4 were synthesized using a MOF-derived strategy. The activation of CuO to CuCCCu species and stabilization of the catalyst were facilitated by the synergistic effect of the CuO/C 3 N 4 interface and CuO nanoparticles, resulting in enhanced catalytic efficacy in the ethynylation of formaldehyde.