High-performance p-Cu2O/n-TaON heterojunction nanorod photoanodes passivated with an ultrathin carbon sheath for photoelectrochemical water splitting
High-performance p-Cu2O/n-TaON heterojunction nanorod photoanodes passivated with an ultrathin carbon sheath for photoelectrochemical water splitting
复制标题
超薄碳鞘钝化的高性能p-Cu2O/n-TaON异质结纳米棒光阳极用于光电化学水分解
DOI：
10.1039/c4ee02403f
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发表时间：
2014-11-01
影响因子：
32.5
通讯作者：
Zhu, Hongmin
中科院分区：
文献类型：
--
作者：
Hou, Jungang;Yang, Chao;Zhu, Hongmin
人们在设计和发现光活性纳米结构（氧）氮化物材料方面做了大量的工作，这些材料可以用作光电化学（PEC）水分解的光阳极。然而，光激发的电子-空穴对复合率高，光稳定性差，极大地限制了它们的实际应用。本文采用溶液法制备了以超薄碳鞘（碳-Cu2O/TaON）作为表面保护层钝化的p型Cu2O/n型TaON异质结纳米棒阵列。由于形状各向异性和p-n异质结结构，碳- cu2o /TaON异质结纳米棒阵列作为集成光阳极，在波长为400 nm时的最大IPCE为59%，在AM 1.5G模拟阳光下1.0 V vs. RHE下达到3.06 mA cm(-2)，照射60 min后仍保持在初始活度的87.3%左右。与TaON和Cu2O/TaON相比，该光阳极不仅起电位负移，而且光电流密度和光稳定性也有显著提高。这些改进是由于p-n异质结器件的高内置电位，该器件被封装在超薄石墨碳护套中，免受电解质的影响。我们的设计引入了材料组件，以提供专用的电荷传输途径，减轻了对材料固有特性的依赖，因此有可能大大拓宽各种现有材料在能源相关应用中的使用范围和方式。
Considerable efforts have been made to design and discover photoactive nanostructured (oxy) nitride materials that can be used as photoanodes for photoelectrochemical (PEC) water splitting. However, the high recombination rate of photoexcited electron-hole pairs and the poor photostability have greatly limited their practical applications. Herein, a p-type Cu2O/n-type TaON heterojunction nanorod array passivated with an ultrathin carbon sheath (carbon-Cu2O/TaON) as a surface protection layer was produced via a solution-based process. Due to the shape anisotropy and p-n heterojunction structure, the photocurrent density of carbon-Cu2O/TaON heterojunction nanorod arrays as the integrated photoanode, with a maximum IPCE of 59% at a wavelength of 400 nm, reached 3.06 mA cm(-2) under AM 1.5G simulated sunlight at 1.0 V vs. RHE and remained at about 87.3% of the initial activity after 60 min irradiation. Not only is the onset potential negatively shifted but the photocurrent density and photostability are also significantly improved for this photoanode compared to those of TaON and Cu2O/TaON. These improvements are due to a high built-in potential in the p-n heterojunction device that is protected from the electrolyte by being encapsulated in an ultrathin graphitic carbon sheath. Our design introduces material components to provide a dedicated charge-transport pathway, alleviating the reliance on the materials' intrinsic properties, and therefore has the potential to greatly broaden where and how various existing materials can be used in energy-related applications.