• Energy Research

The catalytic active sites of NiFe and NiFeCr (oxy)hydroxides are revealed byoperandospectroscopic techonologies for alkaline water oxidation.

Bi0.5Sb1. 5Te3 thin films were deposited on glass substrates by pulsed laser deposition (PLD) method at room temperature. Annealing effect on properties of the films was studied by structural, morphology and physical characterizations. It was found that the as-grown amorphous film crystallizes at annealing temperature of 473 K. A semiconductor-metal transition was observed in annealed films. A linear magnetoresistance (MR) was investigated in the annealed films in a magnetic field up to 13 T without saturation at low temperature.

Developing novel gold nanoclusters as an electrocatalyst can facilitate a completely reversible reaction between S and Na, achieving advanced high-energy-density room-temperature sodium–sulfur batteries.

The bi-functional electrocatalytic activity of CoNC-x/CC nanosheet arrays has been successfully tuned by regulating the valence states and particle size.

Abstract Pd- or Pt-based precious catalysts (PPC) are considered to be the best candidates toward high performance directly ethanol fuel cells (DEFC) applications, owing to their high intrinsic activity for ethanol oxidation reaction (EOR). However, the current major barrier for their commercialization is incompletely oxidized intermediates (IOI, such as CO) that poison the catalysts to affect the durability of the cells. Meanwhile, deactivated PPC catalyst is difficult to be recycled, thus impairing the economic benefits for the commercial applications. Moreover, because of the side effects of additive corrosion and aging, the carbon and organic binders widely used in current catalyst design would make the interactions of the IOI more complex to accelerate activity loss. Here, we report a Pd/amorphous SrRuO3 (Pd/a-SrRuO3) hybrid film as a promising material to overcome these problems. Perovskite SrRuO3 can effectively generate oxygen-contains (*OH, *OOH) for intermediates oxidation, providing an ideal platform to promote self-cleaning of CO on Pd activity sites. On the other hand, in analogy to typical self-adapting effect of amorphous catalyst in oxygen reduction reaction process, metastable state of amorphous SrRuO3 in this work is expected to prolong the activity adaptation region at the initial stage of cycling. Furthermore, our conceptual framework of directly depositing Pd/a-SrRuO3 film on operational electrode provides an effective solution to avoid the side effects related with carbon and binders, leading to superior reactivation phenomena with 98% efficiency. As a result, our designed Pd/a-SrRuO3 hybrid film exhibits superior EOR activity (4.0 A mg-1 Pd), durability (i-t, 60,000s), self-adapting region (exceeding 400 cycles with ending activity of 3.0 A mg-1 Pd at 1000th cycle), and also a long-term operation (CP) up to 300,000s with 10 times reactivation. This demonstration of a Pd/Pt-based hybrid catalyst with dual-capability of self-cleaning and self-adapting characteristics is an important step towards the development of highly durable EOR catalysts, with an enormous potential to promote practical application of DEFC.

Room-temperature sodium-ion batteries have been regarded as promising candidates for grid-scale energy storage due to their low cost and the wide distribution of sodium sources. The main scientific challenge for their practical application is to develop suitable anodes with long-term cycling stability and high rate capacity. Here, novel hierarchical three-dimensional porous carbon materials are synthesized through an in situ template carbonization process. Electrochemical examination demonstrates that carbonization temperature is a key factor that affects Na+-ion-storage performance, owing to the consequent differences in surface area, pore volume, and degree of crystallinity. The sample obtained at 600 °C delivers the best sodium-storage performance, including long-term cycling stability (15 000 cycles) and high rate capacity (126 mAh g-1 at 20 A g-1). Pseudocapacitive behavior in the Na+-ion-storage process has been confirmed and studied via cyclic voltammetry. Full cells based on the porous carbon anode and Na3V2(PO4)3-C cathode also deliver good cycling stability (400 cycles). Porous carbon, combining the merits of high energy density and extraordinary pseudocapacitive behavior after cycling stability, can be a promising replacement for battery/supercapacitors hybrid and suggest a design strategy for new energy-storage materials.

The mixed caesium and formamidinium lead triiodide perovskite system (Cs1−xFAxPbI3) in the form of quantum dots (QDs) offers a pathway towards stable perovskite-based photovoltaics and optoelectronics. However, it remains challenging to synthesize such multinary QDs with desirable properties for high-performance QD solar cells (QDSCs). Here we report an effective oleic acid (OA) ligand-assisted cation-exchange strategy that allows controllable synthesis of Cs1−xFAxPbI3 QDs across the whole composition range (x = 0–1), which is inaccessible in large-grain polycrystalline thin films. In an OA-rich environment, the cross-exchange of cations is facilitated, enabling rapid formation of Cs1−xFAxPbI3 QDs with reduced defect density. The hero Cs0.5FA0.5PbI3 QDSC achieves a certified record power conversion efficiency (PCE) of 16.6% with negligible hysteresis. We further demonstrate that the QD devices exhibit substantially enhanced photostability compared with their thin-film counterparts because of suppressed phase segregation, and they retain 94% of the original PCE under continuous 1-sun illumination for 600 h.