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In this study, Cu and Cu2O hybrid nanoparticles were synthesized onto the WO3 nanoflake film using a one-step electrodeposition method. The critical advance is the use of a heterojunction consisting of WO3 flakes and Cu2O as an innovative stack design, thereby achieving excellent performance for CO2 photoreduction with water vapor under visible light irradiation. Notably, with the modified Cu nanoparticles, the selectivity of CH4 increased from nearly 0% to 96.7%, while that of CO fell down from 94.5% to 0%. The yields of CH4, H2 and O2 reached 2.43, 0.32 and 3.45 mmol/gcat after 24 h of visible light irradiation, respectively. The boosted photocatalytic performance primarily originated from effective charge-transfer in the heterojunction and acceleration of electron-proton transfer in the presence of Cu nanoparticles. The S-scheme charge transfer mode was further proposed by the in situ-XPS measurement. In this regard, the heterojunction construction showed great significance in the design of efficient catalysts for CO2 photoreduction application. [ABSTRACT FROM AUTHOR]

The development of WO3-based gas sensors for analysis of acetone in exhaled breath is significant for noninvasive diagnosis of diabetes. A series of Fe-doped hexagonal and monoclinic WO3 phase−junction (Fe−h/m−WO3) sensors were synthesized by the hydrothermal calcination method, and the influences of operating temperature and light irradiation on the response were studied. Under light emitting diode (LED) illumination, Fe−h/m−WO3 exhibited higher responses to acetone than those of the undoped WO3-based sensors at an operating temperature of 260 °C with 90% relative humidity, and good linearity between response and acetone concentration (0.5 to 2.5 ppm) was achieved under the 90% relative humidity condition. Meanwhile, the optimal Fe−h/m−WO3 sensor exhibited high selectivity and stability for a duration of three months. The excellent sensing performance of Fe−h/m−WO3 was attributed to the formation of phase−junction and Fe doping, and these were beneficial for the separation of photon−generated carriers and oxygen adsorption on the WO3 surface, promoting the generation of superoxide radicals, which was demonstrated by electron paramagnetic resonance and photocurrent tests. Additionally, the Fe−doped WO3 phase−junction sample also showed good photocatalytic performance for rhodamine B degradation. This study may provide some insights into rational design of new types of gas sensors and offer an alternative for noninvasive diagnosis of diabetes. [ABSTRACT FROM AUTHOR]

Polymerization-induced phase separation is comparatively applied to fabricating a superhydrophobic micro/nano surface by microwave and ultraviolet (UV) irradiation. The monolithic coatings can be tailored easily on different substrates with excellent chemical and mechanical stability in rigid conditions. Importantly, the patterned filter paper is successfully used for the colorimetric detection of nitrite handily. [ABSTRACT FROM AUTHOR]