新型钯-铜纳米点析氢助催化剂:优化界面氢脱附以实现高效光催化活性

助剂修饰是提高单相光催化剂催化制氢活性的有效策略之一.贵金属Pt是光催化制氢体系中较为理想的助催化剂,但价格高、储量少,严重限制了其广泛应用.在过去几十年中,研究者研发了一系列低成本的非Pt助催化剂,如金属氧化物、碳化物、氮化物、硫化物和磷化物等,并应用于光催化制氢,但其催化活性与Pt助催化剂相比有较大差距.近年来,与...

Palladium-copper nanodot as novel H2-evolution cocatalyst: Optimizing interfacial hydrogen desorption for highly efficient photocatalytic activity

Noble metal palladium (Pd) is well-known as excellent photocatalytic cocatalyst, but its strong ad-sorption to hydrogen causes its limited H2-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 H2-evolution rate via the Pd-Cu alloying effect. Herein, the ultrasmall Pd100-xCux alloy nanodots (2-5 nm) as a novel H2-evolution cocatalyst were integrated with the TiO2 through a simple NaH2PO2-mediated co-deposition route. The resulting Pd100-xCux/TiO2 sample shows the significantly enhanced photocatalytic H2-generation performance (269.2 μmol h-1), which is much higher than the bare TiO2. Based on in situ irradiated X-ray photoelectron spectroscopy (ISI-XPS) and density functional theory (DFT) results, the as-formed Pd100-xCux 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 Pd75Cu25 alloy, thus lead-ing to high photocatalytic H2-evolution activity. Herein, the weakened H adsorption of Pd75Cu25 co-catalyst can be ascribed to the formation of electron-rich Pd after the introduction of weak electro-negativity 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.