Nanoporous BiVO4 Photoanodes with Dual-Layer Oxygen Evolution Catalysts for Solar Water Splitting
Nanoporous BiVO4 Photoanodes with Dual-Layer Oxygen Evolution Catalysts for Solar Water Splitting
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DOI：
10.1126/science.1246913
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发表时间：
2014-02-28
期刊：
影响因子：
56.9
通讯作者：
Choi, Kyoung-Shin
中科院分区：
文献类型：
--
作者：
Kim, Tae Woo;Choi, Kyoung-Shin
钒酸铋 (BiVO4) 的能带结构非常适合用作太阳能水分解中的光电阳极，但其电子空穴分离性能较差。在这里，我们证明了纳米多孔形态（比表面积为 31.8 平方米/克）无需额外掺杂即可有效抑制体载流子复合，与可逆氢电极 (RHE) 相比，在 1.23 伏 (V) 电压下电子-空穴分离率为 0.90。我们通过连续应用两个不同的析氧催化剂（OEC）层FeOOH和NiOOH，增强了到达表面的孔引发水分解化学的倾向，这减少了BiVO4/OEC结处的界面复合，同时在OEC/电解质结处产生了更有利的亥姆霍兹层电势降。由此产生的 BiVO4/FeOOH/NiOOH 光阳极在相对于 RHE 低至 0.6 V 的电势下实现了 2.73 毫安/平方厘米的光电流密度。
Bismuth vanadate (BiVO4) has a band structure that is well-suited for potential use as a photoanode in solar water splitting, but it suffers from poor electron-hole separation. Here, we demonstrate that a nanoporous morphology (specific surface area of 31.8 square meters per gram) effectively suppresses bulk carrier recombination without additional doping, manifesting an electron-hole separation yield of 0.90 at 1.23 volts (V) versus the reversible hydrogen electrode (RHE). We enhanced the propensity for surface-reaching holes to instigate water-splitting chemistry by serially applying two different oxygen evolution catalyst (OEC) layers, FeOOH and NiOOH, which reduces interface recombination at the BiVO4/OEC junction while creating a more favorable Helmholtz layer potential drop at the OEC/electrolyte junction. The resulting BiVO4/FeOOH/NiOOH photoanode achieves a photocurrent density of 2.73 milliamps per square centimenter at a potential as low as 0.6 V versus RHE.