A novel photosensitizer hybrid film (Ir-(cumr) 2 (dabpy) + @NWF-g-MAH) has been designed and synthesized by anchoring a coumarin−Ir(III) complex on a polymer substrate. Photocatalytic tests show that Ir(cumr) 2 (dabpy) + @ NWF-g-MAH displays a long lifetime of over 650 h under visiblelight irradiation. The hydrogen evolution efficiency of Ir-(cumr) 2 (dabpy) + @NWF-g-MAH is nearly 25 times higher than that of [Ir(ppy) 2 (dabpy)] + @NWF-g-MAH in 100 h, and optimizing the average concentration of Ir(cumr) 2 (dabpy) + @ NWF-g-MAH in the hydrogen evolution system improves the hydrogen evolution amount to 12 790 μmol m −2 . This photocatalytic system achieves the best synergy of hydrogen evolution efficiency and lifetime so far. The high performance is derived from the sterically bulky substrate effectively inhibiting the photodegradation of the photosensitizer and the coumarin group with strong visible-light absorption in the visible region. This work provides a novel direction for developing a durable and efficient Ir(III) complex for photocatalytic application.

Developing a photosensitizer with high efficiency and long-term stability for photocatalytic hydrogen evolution is highly desirable yet remains a challenge. Herein, a novel Ir(III) complex-based photosensitizer (Ir3) bearing coumarin and triphenylamine groups is designed. Ir3 exhibits record activity and durability among reported transition metal complexes for photocatalytic hydrogen evolution, with a TON of 198,363 and a duration of 214 h. The excellent photocatalytic performance of Ir3 can be attributed to the synergistic effect of coumarin and triphenylamine, which improves the visible light absorption, charge separation, and electron transfer capacity of photosensitizers. This is an efficient and long-lived Ir(III) photosensitizer constructed on the basis of a synergistic approach, which could provide a new insight for the development of high-performance Ir(III) photosensitizers at the molecular level.