Palladium-copper nanodot as novel H_2-evolution cocatalyst: Optimizing interfacial hydrogen desorption for highly efficient photocatalytic activity
Palladium-copper nanodot as novel H_2-evolution cocatalyst: Optimizing interfacial hydrogen desorption for highly efficient photocatalytic activity
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钯铜纳米点作为新型 H_2 析氢助催化剂：优化界面氢解吸以实现高效光催化活性
DOI：
10.1016/s1872-2067(21)63830-5
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Fan Jiajie
中科院分区：
文献类型：
--
作者：
Xu Jiachao;Gao Duoduo;Yu Huogen;Wang Ping;Zhu Bichen;Wang Linxi;Fan Jiajie
贵金属钯（Pd）是公认的优秀的光催化助催化剂，但其对氢的强吸附导致其析氢活性有限。本研究成功地将过渡金属Cu引入金属Pd中，通过Pd-Cu的合金化效应，减弱金属Pd的吸氢强度，提高其界面h_2析出速率。本文通过简单的nah_2po_2共沉积途径，将超小Pd_(100-x)Cu_x合金纳米点（2-5 nm）作为新型h_2 -析氢共催化剂与TiO_2结合。得到的Pd_(100-x)Cu_x/TiO_2样品的光催化生成h_2的性能显著提高（269.2 μmol h-1），远高于裸TiO_2。原位辐照x射线光电子能谱（si - xps）和密度泛函理论（DFT）结果表明，形成的Pd_(100-x)Cu_x合金纳米点可以有效促进光生电荷的分离，减弱对氢的吸附强度，优化Pd_(75)Cu_（25）合金的氢解吸过程，从而具有较高的光催化析氢活性。其中，Pd_(75)Cu_（25）助催化剂的H吸附减弱可归因于引入弱电负性Cu后形成富电子Pd。优化电子结构以提高界面反应活性的研究为高效光催化剂的开发提供了新的思路。
Noble metal palladium(Pd) is well-known as excellent photocatalytic cocatalyst, but its strong adsorption to hydrogen causes its limited H_2-evolution activity. In this study, the transition metal Cu was successfully introduced into the metallic Pd to weaken its hydrogen-adsorption strength to improve its interfacial H_2-evolution rate via the Pd-Cu alloying effect. Herein, the ultrasmall Pd_(100–x)Cu_x alloy nanodots(2–5 nm) as a novel H_2-evolution cocatalyst were integrated with the TiO_2 through a simple NaH_2PO_2-mediated co-deposition route. The resulting Pd_(100–x)Cu_x/TiO_2 sample shows the significantly enhanced photocatalytic H_2-generation performance(269.2 μmol h–1), which is much higher than the bare TiO_2. Based on in situ irradiated X-ray photoelectron spectroscopy(ISI-XPS) and density functional theory(DFT) results, the as-formed Pd_(100–x)Cu_x alloy nanodots can effectively promote the separation of photo-generated charges and weak the adsorption strength for hydrogen to optimize the process of hydrogen-desorption process on Pd_(75)Cu_(25) alloy, thus leading to high photocatalytic H_2-evolution activity. Herein, the weakened H adsorption of Pd_(75)Cu_(25) cocatalyst can be ascribed to the formation of electron-rich Pd after the introduction of weak electronegativity Cu. The present work about optimizing electronic structure for promoting interfacial reaction activity provides a new sight for the development of the highly efficient photocatalysts.