Cobalt catalyst grafted CdTeS quantum dots on porous NiO as photocathode for H2 evolution under visible light

Co complex [(tpy-NH 2 ) 2 Co]Cl 2 was synthesized for the first time. • CdTeS QDs and Co-1 loading conditions maximize photocathode performance. • The photocathode achieves 82 μA cm −2 photocurrent density and sustains over 3 h. • The photocathode produces 2.9 μmol H₂ with a Faradaic efficiency of 92.5%. The initial construction of a photocathode utilized CdTeS quantum dots (QDs), leveraging their remarkable photoelectric efficiency and photostability. The Co-1-CdTeS-NiO photocathode was fabricated by depositing a porous mesh NiO film on conductive glass as the substrate, preparing CdTeS QDs via the hydrothermal method, and loading them onto the NiO film surface. A non-precious metal [(tpy-NH₂)₂Co]Cl₂ complex was synthesized to replace the precious metal Pt as a hydrogen evolution co-catalyst. When subjected to visible light irradiation with an applied bias voltage of −0.1 V (vs. NHE), the photocurrent density reached 82 μA cm −2 and remained stable at 80 μA cm −2 over a 3 h stability test. Simultaneously, the photocathode generated 1.8 μmol of hydrogen gas, achieving a Faraday efficiency of 92.5%, thereby showcasing its highly efficient photocatalytic capabilities. Download: Download high-res image (130KB) Download: Download full-size image