Hofmann-type MOF-derived CuNiOx photocathode for effective PEC H2 production

A novel mixed metal oxide of CuNiO x has been successfully obtained via electrosynthesis and thermal conversion of a Hofmann-type MOF Cu(pz) 2 [Ni(CN) 4 ] (pz = pyrazine). CuNiO x has demonstrated a significant enhancement in light absorption within a visible light range, leading to an impressive increase in photocurrent density and photocatalytic activity during light irradiation compared to CuO. The exceptional photoelectrochemical properties of the photocathodes of CuNiO x have been studied using multiple photoelectrochemical instrumental techniques, which proved the electrodes were stable over the whole water photolysis. The coupling of two metal centers has explained their outstanding performance. • A novel CuNiO x photocathode derived from Hofmann-type MOF was prepared. • CuNiO x shows significant improvement in photocatalytic activity towards H 2 production. • CuNiO x outperforms CuO in hydrogen evolution due to Cu-Ni synergy. • Spectroscopic studies highlight CuO and NiO roles in charge separation.