揭示 g-C3N4 纳米片 Z 型异质结构上原位生长的 CdSe 量子点的双功能光/电催化活性，用于高效产氢,ACS Catalysis

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揭示 g-C3N4 纳米片 Z 型异质结构上原位生长的 CdSe 量子点的双功能光/电催化活性，用于高效产氢
ACS Catalysis ( IF 11.3 ) Pub Date : 2024-01-02 , DOI: 10.1021/acscatal.3c03632
Amir Mehtab ₁ , Tokeer Ahmad ₁

Affiliation

采用连续离子层吸附反应(SILAR)方法在gC ₃ N ₄纳米片表面沉积多个CdSe量子点(QD)。_{与gC 3} N ₄的单个部分相比，所制备的异质结构对氧（OER）和析氢反应（HER）表现出改进的双功能光催化和电催化活性。值得注意的是，经过30次SILAR循环优化的CdSe QDs/gC ₃ N ₄异质结构在碱性条件下的OER和HER反应中表现出高性能和稳定性。所制备的异质结构催化剂还表现出对H ₂析出反应的有效光催化活性，并在三乙醇胺作为牺牲剂存在下产生4306μmol H _{2气体，表观量子产率为23.8％。}光致发光光谱、电子顺磁共振和阻抗光谱表明，gC ₃ N ₄纳米片和 CdSe QD 之间的协同作用可带来更高的催化活性，如获得 10 mA cm ^–2电流密度的低过电势（147 和 218 mV）所示分别用于 HER 和 OER 反应。此外，还利用原位傅里叶变换红外光谱、液相色谱-质谱和高效液相色谱测定了光化学中间产物，以证实TEOA通过捕获空穴成功氧化。结果与光生电子以Z型方式从gC ₃ N ₄纳米片的导带(CB)转移到CdSe QD的价带(VB)的事实一致。

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Unveiling the Bifunctional Photo/Electrocatalytic Activity of In Situ Grown CdSe QDs on g-C3N4 Nanosheet Z-Scheme Heterostructures for Efficient Hydrogen Generation

The successive ionic layer adsorption and reaction (SILAR) method was used to deposit several CdSe quantum dots (QDs) on the surface of g-C₃N₄ nanosheets. In comparison to the single moiety of g-C₃N₄, as-prepared heterostructures displayed an improved bifunctional photo- and electrocatalytic activity for oxygen (OER) and hydrogen evolution reactions (HER). Significantly, the 30 SILAR cycles optimized CdSe QDs/g-C₃N₄ heterostructure exhibited high performances and stabilities for the OER and HER reaction in alkaline conditions. The as-prepared heterostructure catalyst also exhibited an efficient photocatalytic activity toward the H₂ evolution reaction and produced 4306 μmol of H₂ gas with 23.8% of apparent quantum yield in the presence of triethanolamine as a sacrificial agent. Photoluminescence spectroscopy, electron paramagnetic resonance, and impedance spectroscopy suggest that the synergy between g-C₃N₄ nanosheets and CdSe QDs leads to higher catalytic activities, as indicated by the low overpotentials of 147 and 218 mV to obtain a 10 mA cm^–2 current density for the HER and OER reactions, respectively. Furthermore, in situ Fourier transform infrared spectroscopy, liquid chromatography–mass spectroscopy, and high-performance liquid chromatography were conducted to determine the photochemical intermediate products to confirm the successful oxidation of TEOA by capturing holes. The outcome is in accordance with the fact that the photogenerated electrons are transferred from the conduction band (CB) of g-C₃N₄ nanosheets to the valence band (VB) of CdSe QDs in a Z-scheme manner.

更新日期：2024-01-02

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