The development of a high-performance electrocatalyst for oxygen evolution reaction (OER) is imperative but challenging. Here, a partial sulfidation route to construct Ni 2 Fe-LDH/FeNi 2 S 4 heterostructure on nickel foam (Ni 2 Fe-LDH/ FeNi 2 S 4 /NF) by adjusting the hydrothermal duration is reported. The heterostructures afford abundant hydroxide/sulfide interfaces that offer plentiful active sites, rapid charge and mass transfer, favorable adsorption energy to oxygenated species (OH − and OOH) evidenced by the density functional theory calculations, which synergistically boost the alkaline water oxidation. In the 1.0 m KOH solution, Ni 2 Fe-LDH/FeNi 2 S 4 /NF exhibits an excellent OER catalytic activity with a much smaller overpotential (240 mV) to reach the current density of 100 mA cm −2 than single-phase Ni 2 Fe-LDH/NF (279 mV) or FeNi 2 S 4 /NF (271 mV). More impressively, 2000 cycles of cyclic voltammetry scan for water oxidation results in the formation of a sulfate layer over the catalyst. The corresponding post-catalyst demonstrates better OER activity and durability than the initial one in the alkaline simulated seawater electrolyte. The post-Ni 2 Fe-LDH/FeNi 2 S 4 /NF delivers smaller overpotential (250 mV) at 100 mA cm −2 and longer stability time than the original form (260 mV). The post-formed sulfate passivating layer is responsible for the outstanding corrosion resistance of the salty-water oxidation anode since it can effectively repel chloride.

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Flexible pressure sensors have attracted considerable research interest and efforts owing to their broad application prospects in wearable devices, health monitoring, and human−machine interfacing. High-sensitivity, wide-workable-range, and low-cost pressure sensors are the primary requirement in practical application. In this work, flexible pressure sensors with high sensitivity in a wide pressure range are constructed by introducing a knoll-like microstructured surface into a percolative thermoplastic polyurethane/carbon black sensitive film, using a facile, efficient, and cost-effective screen-printing route. The prepared pressure sensors exhibit an ultrawide sensing pressure range of 0−1500 kPa, high sensitivity (5.205 kPa −1 in the range of 0−100 kPa and 0.63 kPa −1 over 1200 kPa), fast response, and excellent durability for more than 30 000 cycles. We demonstrated the applications of our pressure sensors in health monitoring, such as detection of wrist radial artery pulse waves, phonation, and vibrations. In addition, the proposed sensors showed the potential in object manipulation and human−machine interfacing, capable of detecting spatial pressure distribution, measuring grip forces, and monitoring gas pressures.