Photocatalytic Water Oxidation with Nonsensitized IrO2 Nanocrystals under Visible and UV Light
Photocatalytic Water Oxidation with Nonsensitized IrO2 Nanocrystals under Visible and UV Light
复制标题
DOI：
10.1021/ja200144w
复制
发表时间：
2011-05-18
影响因子：
15
通讯作者：
Osterloh, Frank E.
中科院分区：
文献类型：
--
作者：
Frame, F. Andrew;Townsend, Troy K.;Osterloh, Frank E.
金红石IrO 2被认为是水氧化的最佳电催化剂之一。在这里，我们报告意想不到的光催化水氧化活性的1.98 nm +/- 0.11 nm琥珀酸稳定的IrO 2纳米晶体。从过硫酸盐和硝酸银的水溶液中，未敏化的粒子以高达0.96 μ mol·min（-1）的初始速率和至少0.19%的量子效率（在530 nm处测量）放出氧。催化过程由从Ir-d（t（2g））到Ir-d（e（g））带（1.5-2.75 eV）的可见光激发和由从O-p带到Ir-d（e（g））带（>3.0 eV）的紫外光激发驱动。光生载流子的形成可以用表面光电压谱直接观察到。研究结果揭示了IrO 2在染料敏化水分解体系中的作用。
Rutile IrO2 is known as being among the best electrocatalysts for water oxidation. Here we report on the unexpected photocatalytic water oxidation activity of 1.98 nm +/- 0.11 nm succinic acid-stabilized IrO2 nanocrystals. From aqueous persulfate and silver nitrate solution the nonsensitized particles evolve oxygen with initial rates up to 0.96 mu mol min(-1) and with a quantum efficiency of at least 0.19% (measured at 530 nm). The catalytic process is driven by visible excitations from the Ir-d(t(2g)) to the Ir-d(e(g)) band (1.5-2.75 eV) and by ultraviolet excitations from the O-p band to the Ir-d(e(g)) (>3.0 eV) band. The formation of the photogenerated charge carriers can be directly observed with surface photovoltage spectroscopy. The results shed new light on the role of IrO2 in dye- and semiconductor-sensitized water splitting systems.