Interfacial coordination anchoring of eosin Y on Ce-BTC nanorods for stable solar hydrogen evolution

Cerium-based metal-organic frameworks are attractive photocatalysts, but their hydrogen evolution performance is limited by weak visible-light absorption and Ce⁴⁺-related electron trapping. In this work, eosin Y (EY) was anchored onto Ce-BTC nanorods by solvothermal sensitization to build a more stable dye-MOF interface. Compared with room-temperature sensitized PM/Ce-BTC, ST/Ce-BTC shows spectroscopic evidence consistent with carboxylate-mediated coordination anchoring of EY at the Ce sites of Ce-BTC. ST/Ce-BTC exhibits broader visible-light absorption and a lower interfacial charge-transfer resistance than PM/Ce-BTC. FT-IR and XPS analyses support carboxylate-mediated coordination anchoring of EY at Ce sites, while XPS and electrochemical measurements show a higher relative EY loading and a lower charge-transfer resistance of 115.9 Ω for ST/Ce-BTC. Under simulated AM 1.5G irradiation, ST/Ce-BTC gives an H₂ evolution rate of 2.771 mmol g^-1 h^-1, 38.0 times higher than that of bare Ce-BTC. PM/Ce-BTC exhibits a comparable initial H₂ evolution rate, but its activity decreases markedly during prolonged reaction. In contrast, the activity of ST/Ce-BTC is largely restored after TEOA replenishment, indicating a more durable sensitized interface. This work shows that replacing weak dye adsorption with Ce-site coordination anchoring can improve the operational stability of dye-sensitized Ce-MOF photocatalysts.