For efficient catalysis and electrocatalysis well‐designed, high‐surface‐area support architectures covered with highly dispersed metal nanoparticles with good catalyst‐support interactions are required. In situ grown Ni nanoparticles on perovskites have been recently reported to enhance catalytic activities in high‐temperature systems such as solid oxide cells (SOCs). However, the micrometer‐scale primary particles prepared by conventional solid‐state reactions have limited surface area and tend to retain much of the active catalytic element within the bulk, limiting efficacy of such exsolution processes in low‐temperature systems. Here, a new, highly efficient, solvothermal route is demonstrated to exsolution from smaller scale primary particles. Furthermore, unlike previous reports of B‐site exsolution, it seems that the metal nanoparticles are exsolved from the A‐site of these perovskites. The catalysts show large active site areas and strong metal‐support interaction (SMSI), leading to ≈26% higher geometric activity (25 times higher mass activity with 1.4 V of Eon‐set) and stability for oxygen‐evolution reaction (OER) with only 0.72 µg base metal contents compared to typical 20 wt% Ni/C and even commercial 20 wt% Ir/C. The findings obtained here demonstrate the potential design and development of heterogeneous catalysts in various low‐temperature electrochemical systems including alkaline fuel cells and metal–air batteries.

We develop structure-property relations for organic field effect transistors using a polymer/small-molecule blend active layer. An array of bottom gate, bottom contact devices using a polymeric dielectric and a semiconductor layer of 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) is described and shown to have good device-to-device uniformity. We describe the nucleation and growth processes that lead to the formation of four structurally distinct regimes of the diF-TES-ADT semiconductor film, including evidence of layer-by-layer growth when spin-coated onto silver electrodes and an organic dielectric as part of a polymer blend. Devices exhibiting a maximum saturation mobility of 1.5 cm 2 V À1 s À1 and maximum current modulation ratio (I on /I off) of 1.20 Â 10 5 are visualised by atomic force microscopy and appear to have excellent domain connectivity and aligned crystallography across the channel. In contrast, poorly performing devices tend to show a phase change in semiconductor crystallinity in the channel centre. These observations are enhanced by direct visualisation of the potential drop across the channel using Kelvin probe microscopy, which confirms the importance of large, well-aligned and well-connected semiconductor domains across the transistor channel.

Symmetrical solid oxide cells (SSOCs) have been extensively recognized due to their simple cell configuration, low cost and reliability. High performance electrode is the key determinant of SSOCs. Herein, a multifunctional perovskite oxide La0.6Ca0.4Fe0.8Ni0.2O3-δ (LCaFN) is investigated as electrode for SSOCs. The results confirm that LCaFN shows excellent oxygen reduction reaction (ORR), oxygen evolution reaction (OER), carbon dioxide reduction reaction (CO2-RR) and hydrogen oxidation reaction (HOR) catalytic activity. In SOFC mode, the SSOCs with LCaFN achieve good electrochemical performance with maximum power density of 300 mW cm -2 at 800 °C. For pure CO2 electrolysis in SOEC mode, polarization resistance of 0.055 Ω cm 2 and current density of 1.5 A cm -2 are achieved at 2.0 V at 800 °C. Besides, the cell shows excellent stability both in SOFC mode and SOEC mode.Most importantly, SSOCs with symmetrical LCaFN electrodes show robust and regenerative performance under anodic or cathodic process during the switching gas, showing the great reliability of the SSOCs. The results show that this novel electrode offers a promising strategy for operation of SSOCs.

Highly-strained coherent interfaces, between rhombohedral-like (R) and tetragonal-like (T) phases in BiFeO3 thin films, often show enhanced electrical conductivity in comparison to non-interfacial regions. In principle, changing the population and distribution of these interfaces should therefore allow different resistance states to be created. However, doing this controllably has been challenging to date. Here, we show that local thin film phase microstructures (and hence R-T interface densities) can be changed in a thermodynamically predictable way (predictions made using atomistic simulations) by applying different combinations of mechanical stress and electric field. We use both pressure and electric field to reversibly generate metastable changes in microstructure that result in very large changes of resistance of up to 108%, comparable to those seen in Tunnelling Electro-Resistance (TER) devices.