Developing efficient catalysts and photosensitizers is crucial for the construction of effective photocatalytic H2-evolving systems.Here,we report the facile preparation of Coumarin-modified Ir(III)complexes(PS-2 and ...Developing efficient catalysts and photosensitizers is crucial for the construction of effective photocatalytic H2-evolving systems.Here,we report the facile preparation of Coumarin-modified Ir(III)complexes(PS-2 and PS-3)and their utilization as chromophores to drive favorable photocatalytic H2 evolution using Ni-substituted polyoxometalate(Ni_(3)PW_(10))catalyst and triethanolamine(TEOA)as an electron donor.Compared with the commercially available unmodified Ir(III)complex(PS-1),both PS-2 and PS-3 displayed intensive absorption in the range of 400–550 nm with ε_(max) of 110,620 and 91,430 M^(−1) cm6(−1),respectively.Varying the substitutes on the bipyridine ligand affected their physicochemical properties and the corresponding photocatalytic activity dramatically.Under photocatalytic conditions,the quantity of H2 molecules generated by PS-2-and PS-3-containing systems were 13.1 and 2.1 times,respectively,that of the PS-1-containing system.When PS-2 was used as a photosensitizer,the highest turnover number(TON)of 19,739 was obtained versus Ni_(3)PW_(10) catalyst.Various spectroscopic and computational studies have revealed that factors such as strong and broad visible-light-absorbing ability,long-lived triplet state,suitable redox potential,opposed by using polyoxometalate(POM)catalyst,and large highest occupied molecular orbital(HOMO)–lowest unoccupied molecular orbital(LUMO)gap of PS-2 attributed to drastically enhanced photocatalytic activity.展开更多
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(nos.21871025 and 21831001)the Recruitment Program of Global Experts(Young Talents),and the BIT Teli Young Fellow Program.
文摘Developing efficient catalysts and photosensitizers is crucial for the construction of effective photocatalytic H2-evolving systems.Here,we report the facile preparation of Coumarin-modified Ir(III)complexes(PS-2 and PS-3)and their utilization as chromophores to drive favorable photocatalytic H2 evolution using Ni-substituted polyoxometalate(Ni_(3)PW_(10))catalyst and triethanolamine(TEOA)as an electron donor.Compared with the commercially available unmodified Ir(III)complex(PS-1),both PS-2 and PS-3 displayed intensive absorption in the range of 400–550 nm with ε_(max) of 110,620 and 91,430 M^(−1) cm6(−1),respectively.Varying the substitutes on the bipyridine ligand affected their physicochemical properties and the corresponding photocatalytic activity dramatically.Under photocatalytic conditions,the quantity of H2 molecules generated by PS-2-and PS-3-containing systems were 13.1 and 2.1 times,respectively,that of the PS-1-containing system.When PS-2 was used as a photosensitizer,the highest turnover number(TON)of 19,739 was obtained versus Ni_(3)PW_(10) catalyst.Various spectroscopic and computational studies have revealed that factors such as strong and broad visible-light-absorbing ability,long-lived triplet state,suitable redox potential,opposed by using polyoxometalate(POM)catalyst,and large highest occupied molecular orbital(HOMO)–lowest unoccupied molecular orbital(LUMO)gap of PS-2 attributed to drastically enhanced photocatalytic activity.
