Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
J Am Chem Soc. 2013 Jul 17;135(28):10238-41. doi: 10.1021/ja404030x. Epub 2013 Jul 3.
Photoanodes made from BaTaO2N that can harvest visible light up to 660 nm wavelength were fabricated on Ti substrates for achieving efficient water splitting. Both pre-treatment of BaTaO2N particles with an H2 stream and post-necking treatment with TaCl5 effectively increased the photocurrent due to the decreased electrical resistance in the porous BaTaO2N photoanode. A combination of pre-loading of CoO(x) on the BaTaO2N particles and post-loading of RhO(x) significantly improved both the photocurrent and stability under visible light irradiation, along with an obvious negative shift (ca. 300 mV) of the onset potential for water oxidation, while sole loading resulted in a lower photocurrent or insufficient stability. The IPCE value was estimated to be ca. 10% at 1.2 V vs RHE under 600 nm, which is the highest among photoanode materials that can harvest light beyond 600 nm for water oxidation. Photoelectrochemical water splitting into H2 and O2 under visible light was demonstrated using RhO(x)/CoO(x)/BaTaO2N/Ti photoanodes under an externally applied bias larger than 0.7 V to a Pt counter electrode.
在 Ti 基底上制备了能吸收 660nm 波长可见光的 BaTaO2N 光阴极，用于实现高效水分解。BaTaO2N 颗粒先用 H2 流预处理，再用 TaCl5 进行颈缩处理，这两种方法都有效降低了多孔 BaTaO2N 光阴极的电阻，从而提高了光电流。在 BaTaO2N 颗粒上预先负载 CoO(x)并随后负载 RhO(x)，这两种方法结合使用显著提高了在可见光照射下的光电流和稳定性，同时水氧化的起始电位明显负移（约 300mV），而单独负载则会导致光电流较低或稳定性不足。在 600nm 下，在 1.2V 对 RHE 的电位下，IPCE 值估计约为 10%，这是能吸收 600nm 以上波长的光用于水氧化的光阴极材料中最高的。在外加偏压大于 0.7V 的条件下，用 RhO(x)/CoO(x)/BaTaO2N/Ti 光阴极进行可见光下的光电化学水分解，生成 H2 和 O2。
