Bismuth Gadolinium Oxychloride with a Remarkable Visible-Light-Responsive O2 Evolution Activity Promoted by Iodine Doping

Graphical Iodine-doped Bi 2 GdO 4 Cl with a significantly promoted visible-light-responsive O 2 -evolving performance of 154.8 μmol ⋅ h −1 and an apparent quantum efficiency of ∼1.1 % at 420 nm is reported. The incorporation of I − ions causes the extended light absorption and promoted charge separation. Visible-light-responsive bismuth-based oxyhalide has recently attracted extensive attention, however, the promotion of its charge separation is still challenging. Herein, we introduce iodine into Bi 2 GdO 4 Cl to synthetize I-doped Bi 2 GdO 4 Cl (denoted as yI−Bi 2 GdO 4 Cl, 0≤y≤2). The incorporation of I − ions is found to enhance light absorption and to accelerate charge separation by combining various characterizations such as density functional theory calculation, photoelectrochemical test, electrochemical impedance spectroscopy, photoluminescence spectrum, and open-circuit voltage decay. The O 2 -evolving performances of 1I−Bi 2 GdO 4 Cl with optimized dopant concentration of I − ion and IrO 2 loaded 1I−Bi 2 GdO 4 Cl are tremendously enhanced by ca. 4 and 45 times compared to pristine Bi 2 GdO 4 Cl. Notably, The O 2 evolution rate reaches as high as 154.8 μmol ⋅ h −1 with an apparent quantum efficiency of ∼1.1 % at 420 nm. The synthetic iodine-doped photocatalyst remains stable after long-term photoreaction, demonstrating its potential in the field of photocatalysis.