This study reports the synthesis of cadmium sulfide (CdS) nanoparticles on Li⁺-inserted TiO₂ nanotube array (Li-TNA) to fabricate Li-TNA/CdS heterojunction electrodes for photoelectrochemical (PEC) hydrogen production under air mass (AM) 1.5 light and solar visible light (λ > 420 nm). For fabrication of the heterojunction, Li⁺ is rapidly inserted into TNA pre-grown on Ti foil, and CdS is then photodeposited onto the Li-TNA electrodes for varying deposition times. Surface analyses reveal that sub-100-nm polycrystalline CdS particles partly cover the Li-TNA (length: ∼800 nm, pore diameter: ∼100 nm), enabling the heterojunction to utilize AM 1.5 light as well as visible light. In aqueous solutions of sulfide and sulfite, the Li-TNA/CdS exhibits an incident photon-to-current efficiency (IPCE) of ∼20% (λ = 420 nm) while generating H₂ at a Faradaic efficiency of ∼100%. This PEC performance is superior to that of TNA/CdS, which is attributed to the Li⁺-enhanced charge transfer at the TNA/CdS interface. Electrochemical impedance analysis shows that the charge-transfer resistance of the TNA is reduced by ∼60% by Li⁺ insertion. Time-resolved photoluminescence decay profiles further reveal that the charge transfer in Li-TNA is completed within 0.8 ns, which is ∼33% faster than that in TNA. The sample surface is analyzed using scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible spectroscopy, and the PEC behavior of the samples is discussed in detail.

这项研究报告了在Li ⁺插入的TiO ₂纳米管阵列（Li-TNA）上合成硫化镉（CdS）纳米颗粒以制造Li-TNA / CdS异质结电极，用于在空气质量（AM）1.5光下产生光电化学（PEC）氢的情况和太阳可见光（λ> 420 nm）。对于异质结的制造，Li ⁺将其快速插入预先在Ti箔上生长的TNA中，然后将CdS光沉积到Li-TNA电极上以改变沉积时间。表面分析表明，低于100 nm的多晶CdS颗粒部分覆盖了Li-TNA（长度：〜800 nm，孔径：〜100 nm），从而使异质结能够利用AM 1.5光和可见光。在硫化物和亚硫酸盐的水溶液中，Li-TNA / CdS表现出约20％（λ= 420 nm）的入射光子-电流效率（IPCE），同时以约100％的法拉第效率产生H ₂。该PEC性能优于TNA / CdS，这归因于TNA / CdS接口处Li ⁺增强的电荷转移。电化学阻抗分析表明，Li使TNA的电荷转移电阻降低了约60％⁺插入。时间分辨的光致发光衰减曲线进一步表明，Li-TNA中的电荷转移在0.8 ns内完成，比TNA中的电荷转移快约33％。使用扫描电子显微镜，X射线衍射，能量色散X射线光谱，X射线光电子光谱和紫外可见光谱对样品表面进行分析，并对样品的PEC行为进行了详细讨论。