Abstract Cocatalysts play important roles in photocatalytic and photoelectrochemical water splitting reactions. However, the formation of well-defined junctions between low dimensional semiconductors and cocatalysts is still challenging. In this study, CdS nanorod photoanodes loaded with cobalt phosphate (CoPi) cocatalyst were synthesized by a facile two-step route, in which CdS nanorods were prepared using a hydrothermal method followed by photo-assisted electrodeposition of CoPi. It was found that the formation of intimate junctions between CoPi and CdS nanorods in the form of Co–S bonding effectively facilitated the charge separation and lowered the activation energy of the water oxidation reaction. This resulted in highly efficient and stable photoelectrochemical water splitting on the CdS photoanode. The optimal CdS/CoPi photoanode showed a maximum photocurrent of 4.7 mA/cm 2 at 0 V versus reversible hydrogen electrode under an AM 1.5 G solar simulator, which was 5.5-fold higher than that of bare CdS photoanode. This work expands the potential application of the cocatalyst CoPi in CdS photoanode systems and improves our understanding of the nature of cocatalysts with well-defined interface junctions in semiconductors. Graphic Abstract Well-defined interfacial junction with Co–S bonding over cobalt phosphate cocatalyzed CdS nanorod photoanode facilitates the charge separation and lowers the activation energy, thus achieving a considerable photocurrent of 4.7 mA/cm 2 at 0 V vs. RHE.

中文翻译：

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磷酸钴助催化剂负载的 CdS 纳米棒光阳极具有明确的结，用于高效光电化学水分裂

摘要 助催化剂在光催化和光电化学分解水反应中起着重要作用。然而，在低维半导体和助催化剂之间形成明确的结仍然具有挑战性。在这项研究中，负载磷酸钴 (CoPi) 助催化剂的 CdS 纳米棒光阳极通过简单的两步法合成，其中 CdS 纳米棒使用水热法制备，然后是 CoPi 的光辅助电沉积。结果表明，CoPi 和 CdS 纳米棒之间以 Co-S 键形式形成的紧密连接有效地促进了电荷分离并降低了水氧化反应的活化能。这导致在 CdS 光阳极上产生高效且稳定的光电化学水分解。最佳的 CdS/CoPi 光阳极在 0 V 下与可逆氢电极在 AM 1.5 G 太阳模拟器下显示出 4.7 mA/cm 2 的最大光电流，比裸 CdS 光阳极高 5.5 倍。这项工作扩展了助催化剂 CoPi 在 CdS 光阳极系统中的潜在应用，并提高了我们对半导体中具有明确界面结的助催化剂性质的理解。图形摘要 在磷酸钴共催化的 CdS 纳米棒光阳极上与 Co-S 键合的明确界面连接促进了电荷分离并降低了活化能，从而在 0 V vs. RHE 下实现了 4.7 mA/cm 2 的相当大的光电流。比裸 CdS 光阳极高 5 倍。这项工作扩展了助催化剂 CoPi 在 CdS 光阳极系统中的潜在应用，并提高了我们对半导体中具有明确界面结的助催化剂性质的理解。图形摘要 在磷酸钴共催化的 CdS 纳米棒光阳极上与 Co-S 键合的明确界面连接促进了电荷分离并降低了活化能，从而在 0 V vs. RHE 下实现了 4.7 mA/cm 2 的相当大的光电流。比裸 CdS 光阳极高 5 倍。这项工作扩展了助催化剂 CoPi 在 CdS 光阳极系统中的潜在应用，并提高了我们对半导体中具有明确界面结的助催化剂性质的理解。图形摘要 在磷酸钴共催化的 CdS 纳米棒光阳极上与 Co-S 键合的明确界面连接促进了电荷分离并降低了活化能，从而在 0 V 与 RHE 下实现了 4.7 mA/cm 2 的相当大的光电流。