The development of photocatalysts with superior activity and stability to produce organic fuels through CO2 reduction under renewable sunlight is of great significance due to the depletion of fossil fuels and severe environmental problems. In this study, we presented a “hitting three birds with one stone” strategy to synthesize carbon layer coated cuprous oxide (Cu2O) mesoporous nanorods on Cu foils via a facile chemical oxidation and subsequent carbonization method. The thin carbon layer not only works as a protective layer to quench the common photocorrosion problem of Cu2O but also endows the sample a mesoporous and one-dimensional nanorod structure, which can facilitate reactant molecule adsorption and charge carrier transfer. Substantially, the coated samples exhibited remarkably improved stability as well as decent activity for CO2 reduction under visible light irradiation. The optimized sample attained an apparent quantum efficiency of 2.07% for CH4 and C2H4 at λ0 400 nm, and 93% activity remained after six photoreduction cycles under visible light. This work provides a facile strategy to address the stability and activity issues of Cu2O under visible light irradiation, which is presumably suitable for other semiconductors as promising candidates for CO2 reduction in artificial photosynthesis.

Carbonaceous and polymer materials are extensively employed as conductor and container to encapsulate sulfur particles and limit polysulfide dissolution. Even so, high-power performance is still far from satisfaction due to the expansion and collapse of the electrode materials during thousands of charge-discharge process. Herein, it is found that colloidal carbon sphere with high elastic coefficient can be utilized as a framework to load sulfur, which can trap soluble polysulfides species in the pores within the sphere and efficaciously improve the electronic conductivity of the cathode. After modified by polyaniline (PAN) through in situ polymerization, PAN-assisted S/C nanosphere (PSCs-73, with 73 wt % sulfur) effectively minimize polysulfide diffusion, enhance the electron transfer rate and overcome the problem of volume expansion. The fabricated PSCs-73 cell shows outstanding long high-power cycling capability over 2500 charge/discharge cycles with a capacity decay of 0.01% per cycle at 5 C. Substantially, this composite can drive 2.28 W white indicators of LED robustly after minutes of charging by three lithium batteries in series, showing a promising potential application in the future.

To explore the influence of wearing different types of masks on people’s health and comfort, an experimental study was conducted through a subjective questionnaire survey, physiological response test, and thermal imaging test. The results showed that, in a warm environment, wearing masks for a long time significantly affected the subjective feelings and physiological reactions of people. After wearing the mask, the personnel feels more hot and humid, the discomfort is significantly increased. At the same time, the mean skin temperature increases, the heart rate increases, and the blood oxygen saturation level decreases, which ultimately leads to a decline in health and comfort levels. Different types of masks have different effects on people. The effects of wearing KN95 masks, gauze masks, medical surgical masks, disposable civilian masks, disposable medical masks, and sponge masks on people’s health and comfort levels are sequentially reduced.

Two-dimensional (2D) materials have attracted tremendous interest due to their fascinating physical and chemical properties and promising applications in nano-electronics, where thermal transport plays a vital role in determining the performance of devices. In this paper, we present a first-principles study of the thermal transport properties of monolayer zinc oxide (ZnO), which has potential applications in nano-electronics and thermoelectrics. The thermal conductivity of monolayer ZnO is found to be as low as 4.5 W m K at 300 K, which is dramatically lower than those of bulk ZnO and lots of other 2D materials. A detailed analysis is performed in the framework of Boltzmann transport theory and electronic structure to understand low thermal conductivity. Most surprisingly, the thermal conductivity of monolayer ZnO slowly decreases with temperature and does not follow the conventional 1/T law. This unusual phonon transport behavior arises from the dominant contribution of optical phonon modes to the overall thermal transport in monolayer ZnO, which has been rarely reported in the literature, and the significantly increased specific heat of the high frequency (optical) phonon modes with increasing temperature, both of which compensate the decrease in the phonon relaxation time. Our study highlights the abnormal thermal transport properties of the new 2D material and we anticipate that this research will motivate the experimentalists to further study other physical and chemical properties of monolayer ZnO for its emerging applications in thermoelectrics, thermal circuits, and nano-/opto-electronics.

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