The efficiency with which renewable fuels and feedstocks are synthesized from electrical sources is limited at present by the sluggish oxygen evolution reaction (OER) in pH-neutral media. We took the view that generating transition-metal sites with high valence at low applied bias should improve the activity of neutral OER catalysts. Here, using density functional theory, we find that the formation energy of desired Ni sites is systematically modulated by incorporating judicious combinations of Co, Fe and non-metal P. We therefore synthesized NiCoFeP oxyhydroxides and probed their oxidation kinetics with in situ soft X-ray absorption spectroscopy (sXAS). In situ sXAS studies of neutral-pH OER catalysts indicate ready promotion of Ni under low overpotential conditions. The NiCoFeP catalyst outperforms IrO and retains its performance following 100 h of operation. We showcase NiCoFeP in a membrane-free CO electroreduction system that achieves a 1.99 V cell voltage at 10 mA cm, reducing CO into CO and oxidizing HO to O with a 64% electricity-to-chemical-fuel efficiency.

This Review describes the state-of-the-art of wearable electronics (smart textiles). The unique and promising advantages of smart electronic textiles are highlighted by comparing them with the conventional planar counterparts. The main kinds of smart electronic textiles based on different functionalities, namely the generation, storage, and utilization of electricity, are then discussed with an emphasis on the use of functional materials. The remaining challenges are summarized together with important new directions to provide some useful clues for the future development of smart electronic textiles.

Mechanical responsiveness in many plants is produced by helical organizations of cellulose microfibrils. However, simple mimicry of these naturally occurring helical structures does not produce artificial materials with the desired tunable actuations. Here, we show that actuating fibres that respond to solvent and vapour stimuli can be created through the hierarchical and helical assembly of aligned carbon nanotubes. Primary fibres consisting of helical assemblies of multiwalled carbon nanotubes are twisted together to form the helical actuating fibres. The nanoscale gaps between the nanotubes and micrometre-scale gaps among the primary fibres contribute to the rapid response and large actuation stroke of the actuating fibres. The compact coils allow the actuating fibre to rotate reversibly. We show that these fibres, which are lightweight, flexible and strong, are suitable for a variety of applications such as energy-harvesting generators, deformable sensing springs and smart textiles.

Upscaling of perovskite solar cells to module scale and affording long-term stability have been recognized as the most important challenges for commercialization of this emerging photovoltaic technology. In a perovskite solar module (PSM), each interface within the device contributes to the efficiency and stability. Here, we employ a holistic interface stabilization strategy by modifying all the relevant layers and interfaces, namely the perovskite layer, charge transporting layers and the device encapsulation to improve the efficiency and stability of PSMs. The treatments were selected to be compatible with low-temperature scalable processing and the module scribing steps. Our unencapsulated PSM achieved a reverse-scan efficiency of 16.6% with a designated area of 22.4 cm 2 . The encapsulated PSM retained approximately 86% 2 of the initial performance after continuous operation for 2000 h under AM 1.5G light illumination, with translates into a T 90 lifetime of 1570 h and an estimated T 80 lifetime of 2680 h.

Solar radiation, especially ultraviolet (UV) light, is a major hazard for most skin-related cancers. The growing needs for wearable health monitoring systems call for a high-performance real-time UV sensor to prevent skin diseases caused by excess UV exposure. To this end, here a novel self-powered p-CuZnS/n-TiO UV photodetector (PD) with high performance is successfully developed (responsivity of 2.54 mA W at 0 V toward 300 nm). Moreover, by effectively replacing the Ti foil with a thin Ti wire for the anodization process, the conventional planar rigid device is artfully turned into a fiber-shaped flexible and wearable one. The fiber-shaped device shows an outstanding responsivity of 640 A W , external quantum efficiency of 2.3 × 10 %, and photocurrent of ≈4 mA at 3 V, exceeding those of most current UV PDs. Its ultrahigh photocurrent enables it to be easily integrated with commercial electronics to function as a real-time monitor system. Thus, the first real-time wearable UV radiation sensor that reads out ambient UV power density and transmits data to smart phones via wifi is demonstrated. This work not only presents a promising wearable health monitor, but also provides a general strategy for designing and fabricating smart wearable electronic devices.

A fiber-shaped supercapacitor that can be stretched over 400% is developed by using two aligned carbon nanotube/polyaniline composite sheets as electrodes. A high specific capacitance of approximately 79.4 F g(-1) is well maintained after stretching at a strain of 300% for 5000 cycles or 100.8 F g(-1) after bending for 5000 cycles at a current density of 1 A g(-1). In particular, the high specific capacitance is maintained by 95.8% at a stretching speed as high as 30 mm s(-1).

Stretchable lithium-ion batteries (LIBs) consisting of an arch structure and a stretchable anode and cathode are developed using a general strategy. The LIB maintains a remarkable and stable electrochemical performance after hundreds of stretching cycles at a strain of 400%. Compared with other stretchable LIBs, which stretch at the device level, but whose components (electrodes) remain rigid, the component-level stretchability is here the design key to the LIB's highly stable performance.

Perovskite photovoltaic (PV) technology toward commercialization relies on high power conversion efficiency (PCE), long lifetime, and low-toxicity in addition to development of scalable fabrication protocols, optimization of large-area solar module structures, and a positive cost–benefit assessment. Although small-area metal halide perovskite solar cells (PSCs) show PCE up to 24.2%, the efficiency gap between small- and large-area PSC devices is still large. Worldwide research efforts have been directed toward developing scalable fabrication strategies for perovskite solar modules. In this Review, we share our view regarding the current-stage challenges for the fabrication of perovskite solar modules with areas greater than 200 cm2, summarize recent progress in minimizing the efficiency gap, and highlight what strategies warrant further investigation for moving perovskite PV technology toward industrial scale. These strategies include learning from other commercialized thin-film PV technologies, analyzing the current status of perovskite solar modules employing solution- and vapor-based scalable fabrication techniques, and optimizing large-area module designs. Considering cost analysis and operational stability profiles, carbon electrode-based devices are particularly promising.