Chemical sensors based on semiconducting metal oxide nanocrystals are of academic and practical significance in industrial processing and environment-related applications. Novel alcohol response sensors using two-dimensional WO(3) nanoplates as active elements have been investigated in this paper. Single-crystalline WO(3) nanoplates were synthesized through a topochemical approach on the basis of intercalation chemistry (Chen et al 2008 Small 4 1813). The as-obtained WO(3) nanoplate pastes were coated on the surface of an Al(2)O(3) ceramic microtube with four Pt electrodes to measure their alcohol-sensing properties. The results show that the WO(3) nanoplate sensors are highly sensitive to alcohols (e.g., methanol, ethanol, isopropanol and butanol) at moderate operating temperatures (260-360 degrees C). For butanol, the WO(3) nanoplate sensors have a sensitivity of 31 at 2 ppm and 161 at 100 ppm, operating at 300 degrees C. For other alcohols, WO(3) nanoplate sensors also show high sensitivities: 33 for methanol at 300 ppm, 70 for ethanol at 200 ppm, and 75 for isopropanol at 200 ppm. The response and recovery times of the WO(3) nanoplate sensors are less than 15 s for all the test alcohols. A good linear relationship between the sensitivity and alcohol concentrations has been observed in the range of 2-300 ppm, whereas the WO(3) nanoparticle sensors have not shown such a linear relationship. The sensitivities of the WO(3) nanoplate sensors decrease and their response times become short when the operating temperatures increase. The enhanced alcohol-sensing performance could be attributed to the ultrathin platelike morphology, the high crystallinity and the loosely assembling structure of the WO(3) nanoplates, due to the advantages of the effective adsorption and rapid diffusion of the alcohol molecules.

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The polymer of MFR was used to fabricate Co9S8 encased in N,S-codoped graphene, which showed comparable electrocatalytic performance to Pt/C and RuO2.

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Thanks to the high theoretical capacity and energy density, abundant resource, low-cost, and environmental friendliness, aluminum-air battery (AAB) has attracted research interests driven by the promise for electricity generator. However, low operating voltage leads to low practical energy density, and restricting the applications of AAB. In this study, the concept of an ultrahigh voltage AAB based on aqueous alkaline-acid hybrid electrolyte is introduced and demonstrated. Meanwhile, the working mechanism is investigated. And the open-circuit voltage of the novel designed battery is 2.56 V, 29.9% higher than conventional alkaline AAB. Thanks to the fluid electrolyte, the decline in discharge voltage caused by the change in pH is overcome. And a high-energy density of 4591 mWh g Al −1 is achieved at a discharge voltage of around 2.08 V at 10 mA cm −2. These results provide a viable approach to improve the performance of Al-air battery.

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Hierarchical tungsten carbide (WC) micro‐/nanocrystals were synthesized by thermal treating a single‐source precursor of the tungstate‐based inorganic–organic hybrid compound in a sealed quartz tube at 1000°–1050°C. The hybrid precursor was synthesized by an acid–base reaction of H2O‐moistened H2WO4 and n‐octylamine in a nonpolar solvent. The X‐ray diffraction results indicated that the product obtained at 1050°C for 2 h consisted of a hexagonal WC phase, and the products obtained at temperatures lower than 1000°C had other phases (e.g., α‐W2C, W or β‐W40.9N9.1) besides the major phase of hexagonal WC. The scanning electron microscopy observations indicated that the hexagonal WC obtained at 1050°C consisted of hierarchical microparticles with a size range of 4–18 μm, and the above microparticles were porous aggregates of WC nanoparticles with crystal sizes of 100–250 nm. The newly developed process could achieve pure WC materials at relative low temperatures using a single‐source precursor, and the porous and hierarchical WC micro‐/nanoparticles would have potential applications in catalysis and superhard composites.