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

Abstract

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 Bi2GdO4Cl to synthetize I‐doped Bi2GdO4Cl (denoted as yI−Bi2GdO4Cl, 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 O2‐evolving performances of 1I−Bi2GdO4Cl with optimized dopant concentration of I− ion and IrO2 loaded 1I−Bi2GdO4Cl are tremendously enhanced by ca. 4 and 45 times compared to pristine Bi2GdO4Cl. Notably, The O2 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.

Internal strain-driven bond manipulation and band engineering in Bi2−xSbxYO4Cl photocatalysts with triple fluorite layers

“…It is notable that the bandgaps for 0.2 ≤ x ≤ 0.8 are among the smallest of oxychloride photocatalysts, with the exception of Bi 2.8 Y 0.2 O 4 Cl with 2.0 eV. 36–38…”