sacrificial acceptor 

https://doi.org/10.1351/goldbook.S05443
Molecular entity that acts as the electron acceptor in a photoinduced electron transfer process and is not restored in a subsequent oxidation process but is destroyed by irreversible chemical conversion.
Source:
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2272 [Terms] [Paper]