Sodium-ion batteries are emerging as a highly promising technology for large-scale energy storage applications. However, it remains a significant challenge to develop an anode with superior long-term cycling stability and high-rate capability. Here we demonstrate that the Na þ intercalation pseudocapacitance in TiO 2 /graphene nanocomposites enables high-rate capability and long cycle life in a sodium-ion battery. This hybrid electrode exhibits a specific capacity of above 90 mA h g -1 at 12,000 mA g -1 (B36 C). The capacity is highly reversible for more than 4,000 cycles, the longest demonstrated cyclability to date. First-principle calculations demonstrate that the intimate integration of graphene with TiO 2 reduces the diffusion energy barrier, thus enhancing the Na þ intercalation pseudocapacitive process. The Na-ion intercalation pseudocapacitance enabled by tailor-deigned nanostructures represents a promising strategy for developing electrode materials with high power density and long cycle life.

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Good electronic transport capacity and low lattice thermal conductivity are beneficial for thermoelectric applications. In this study, the potential use as a thermoelectric material for the recently synthesized two-dimensional TiS monolayer is explored by applying first-principles method combined with Boltzmann transport theory. Our work demonstrates that carrier transport in the TiS sheet is orientation-dependent, caused by the difference in charge density distribution at band edges. Due to a variety of Ti-S bonds with longer lengths, we find that the TiS monolayer shows thermal conductivity much lower compared with that of transition-metal dichalcogenides such as MoS. Combined with a high power factor along the y-direction, a considerable n-type ZT value (3.1) can be achieved at moderate carrier concentration, suggesting that the TiS monolayer is a good candidate for thermoelectric applications.

All-inorganic perovskite quantum dots suffer from poor stability in a humid and heat environment. In this article, CsPbBr3 quantum dots (CsPbBr3 QDs) are stabilized by coating nanoscale alumina on a CsPbBr3 QDs-silica luminescent sphere (CsPbBr3 QDs-SLS) via atomic layer deposition (ALD). Utilizing the intrinsic reactivity differences toward precursors, the surface defect sites of CsPbBr3 QDs are selectively passivated. The inorganic alumina coating layers can effectively reduce the ion migration and crystal deformation of CsPbBr3 QDs. In situ quartz crystal microbalance measurements show that organic ligands remain attached to the CsPbBr3 QDs surface during the ALD coating process. NMR, XPS, and first-principles calculations are performed to reveal the interaction strength between CsPbBr3 QDs-SLS and precursors. The surface passivation of alumina on CsPbBr3 QDs-SLS effectively stabilizes the QDs without reducing the photoluminescent quantum yield.

Improving the low-temperature activity (below 100 °C) and noble-metal efficiency of automotive exhaust catalysts has been a continuous effort to eliminate cold-start emissions, yet great challenges remain. Here we report a strategy to activate the low-temperature performance of Pt catalysts on Cu-modified CeO2 supports based on redox-coupled atomic layer deposition. The interfacial reducibility and structure of composite catalysts have been precisely tuned by oxide doping and accurate control of Pt size. Cu-modified CeO2-supported Pt sub-nanoclusters demonstrate a remarkable performance with an onset of CO oxidation reactivity below room temperature, which is one order of magnitude more active than atomically-dispersed Pt catalysts. The Cu-O-Ce site with activated lattice oxygen anchors deposited Pt sub-nanoclusters, leading to a moderate CO adsorption strength at the interface that facilitates the low-temperature CO oxidation performance.