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In this work, photoelectric responses of nanocrystalline WO3 film to humidity under UV light irradiation were investigated. Nanocrystalline WO3 film with porous structure was prepared on Al2O3 substrate by the technology of screen printing and the subsequent heat treatment. The as-prepared nanocrystalline WO3 film was characterized with X-ray diffraction (XRD) and field-emission gun scanning electron microscopy (FE-SEM). The time-dependent photoelectric responses of nanocrystalline WO3 film were studied by exposing it to a wide humidity range of 20–80% relative humidity (RH) at room temperature under UV light irradiation. High performance photoelectric responses of nanocrystalline WO3 film to humidity were observed. To illustrate it, a possible explanation for the photoelectric responses to humidity was proposed. On the basis of the results, the high performance photoelectric responses of WO3 to humidity will provides a new insight into the design and fabrication of advanced photo-activated humidity sensors.

In this work, porous NiMn2O4 nanosheets with large surface areas are successfully grown by a hydrothermal method and examined as electrodes for supercapacitors. Results have shown that the supercapacitor based on NiMn2O4 electrodes exhibits the highest specific capacitance of 1321.6 F g−1 at a scan rate of 2 A g−1, much higher than those of other supercapacitors made of metal oxides and composites. The NiMn2O4 supercapacitor also shows a good cycling behavior, only 6.5 % capacitance decay after 1500 cycles. The NiMn2O4 nanosheets possess a robust mechanical adhesion to Ni foam, which has been demonstrated by an ultrasonication test.

In this work, we synthesized high-quality InAs nanowires by a convenient chemical vapor deposition method, and developed a simple laser heating method to measure the thermal conductivity of a single InAs nanowire in air. During the measurement, a focused laser was used to heat one end of a freely suspended nanowire, with its other end embedded into a carbon conductive adhesive. In order to obtain the thermal conductivity of InAs nanowires, the heat loss in the heat transfer process was estimated, which includes the heat loss through air conduction, the heat convection, and the radiation loss. The absorption ratio of the laser power in the InAs nanowire was calculated. The result shows that the thermal conductivity of InAs nanowires monotonically increases from 6.4 W m−1 K−1 to 10.5 W m−1 K−1 with diameters increasing from 100 nm to 190 nm, which is ascribed to the enhanced phonon-boundary scattering.