Dual-Atom Support Boosts Nickel-Catalyzed Urea Electrooxidation

Nickel-based catalysts have been regarded as one of the most promising electrocatalysts for urea oxidation reaction (UOR), however, their activity is largely limited by the inevitable self-oxidation reaction of Ni species (NSOR) during the UOR. Here, we proposed an interface chemistry modulation strategy to trigger the occurrence of UOR before the NSOR via constructing a 2D/2D heterostructure that consists of ultrathin NiO anchored Ru-Co dual-atom support (Ru-Co DAS/NiO). Operando spectroscopic characterizations confirm this unique triggering mechanism on the surface of Ru-Co DAS/NiO. Consequently, the fabricated catalyst exhibits outstanding UOR activity with a low potential of 1.288 V at 10 mA cm-2 and remarkable long-term durability for more than 330 h operation. DFT calculations and spectroscopic characterizations demonstrate that the favorable electronic structure induced by this unique heterointerface endows the catalyst energetically more favorable for the UOR than the NSOR.

Ligand-Assisted Coupling Manipulation for Efficient and Stable FAPbI3 Colloidal Quantum Dot Solar Cells

For emerging perovskite quantum dots (QDs), understanding the surface features and their impact on the materials and devices is becoming increasingly urgent. In this family, hybrid FAPbI₃ QDs (FA: formamidium) exhibit higher ambient stability, near-infrared absorption and sufficient carrier lifetime. However, hybrid QDs suffer from difficulty in modulating surface ligand, which is essential for constructing conductive QD arrays for photovoltaics. Herein, assisted by an ionic liquid formamidine thiocyanate, we report a facile surface reconfiguration methodology to modulate surface and manipulate electronic coupling of FAPbI₃ QDs, which is exploited to enhance charge transport for fabricating high-quality QD arrays and photovoltaic devices. Finally, a record-high efficiency approaching 15 % is achieved for FAPbI₃ QD solar cells, and they retain over 80 % of the initial efficiency after aging in ambient environment (20-30 % humidity, 25 °C) for over 600 h.

Ru-Co Pair Sites Catalyst Boosts the Energetics for the Oxygen Evolution Reaction

Manipulating the coordination environment of the active center via anion modulation to reveal tailored activity and selectivity has been widely achieved, especially for carbon-based single-atom site catalysts (SACs). However, tuning ligand fields of the active center by single-site metal cation regulation and identifying the effects on the resulting electronic configuration is seldom explored. Herein, we propose a single-site Ru cation coordination strategy to engineer the electronic properties by constructing a Ru/LiCoO₂ SAC with atomically dispersed Ru-Co pair sites. Benefitting from the strong electronic coupling between Ru and Co sites, the catalyst possesses an enhanced electrical conductivity and achieves near-optimal oxygen adsorption energies. Therefore, the optimized catalyst delivers superior oxygen evolution reaction (OER) activity with low overpotential, the high mass activity of 1000 A g_oxide ^-1 at a small overpotential of 335 mV, and excellent long-term stability. It also exhibits rapid kinetics with superior rate capability and outstanding durability in a zinc-air battery.