ZnO is an important n-type semiconductor sensing material. Currently, much attention has been attracted to finding an effective method to prepare ZnO nanomaterials with high sensing sensitivity and excellent selectivity. A three-dimensionally ordered macroporous (3DOM) ZnO nanostructure with a large surface area is beneficial to gas and electron transfer, which can enhance the gas sensitivity of ZnO. Indium (In) doping is an effective way to improve the sensing properties of ZnO. In this paper, In-doped 3DOM ZnO with enhanced sensitivity and selectivity has been synthesized by using a colloidal crystal templating method. The 3DOM ZnO with 5 at. % of In-doping exhibits the highest sensitivity (∼88) to 100 ppm ethanol at 250 °C, which is approximately 3 times higher than that of pure 3DOM ZnO. The huge improvement to the sensitivity to ethanol was attributed to the increase in the surface area and the electron carrier concentration. The doping by In introduces more electrons into the matrix, which is helpful for increasing the amount of adsorbed oxygen, leading to high sensitivity. The In-doped 3DOM ZnO is a promising material for a new type of ethanol sensor.

a-MoO 3 nanobelts were successfully prepared by a facile hydrothermal method with sodium molybdate (Na 2 MoO 4 ) as the Mo source and NaCl as the capping agent. The as-prepared products were characterized using Fourier transformation infrared spectrophotometry (FT-IR), X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and selected area electronic diffraction (SAED) and their pseudocapacitive properties were investigated in a 0.5 M aqueous Li 2 SO 4 solution by cyclic voltammetry (CV), chronopotentiometry (CP) and AC impendence. The results show that the dimensions of the as-prepared a-MoO 3 nanobelts are 200-400 nm in width, ca. 60 nm in thickness and 3-8 mm in length. The redox potential for the a-MoO 3 nanobelts is found in the range of À0.3 to À1.0 V vs. SCE, which indicates that the a-MoO 3 nanobelts can be used as anode electrode materials for hybrid supercapacitors. The specific capacitances of the a-MoO 3 nanobelts at 0.1, 0.25, 0.5 and 1 A g À1 are 369, 326, 256 and 207 F g À1 , respectively. The maximum specific capacitance of the a-MoO 3 nanobelts is much higher than those of MoO 3 nanoplates with 280 F g À1 , MoO 3 nanowires with 110 F g À1 and MoO 3 nanorods with 30 F g À1 recently reported in literature. Furthermore, the a-MoO 3 nanobelt electrode exhibits a good cycle stability with more than 95% of the initial specific capacitance maintained after 500 cycles. Additionally, the present route to prepare nanostructured MoO 3 is much less expensive than those with Mo powders as the Mo source. Overall, the obtained high performance a-MoO 3 nanobelts could be a promising electrode material for supercapacitors.

Yolk-shell Au/CeO2 (Y-Au/CeO2) and encapsulated Au/CeO2 (E-Au/CeO2) nanocatalysts were prepared by using silica templates. A strong metal-support interaction (SMSI) in the Au/CeO2 nanostructures induced by different pretreatment atmospheres and its influence on CO oxidation were studied. E-Au/CeO2 pretreated in O2 had the best performance, followed by Y-Au/CeO2 pretreated in O2, Y-Au/CeO2 pretreated in H2, and E-Au/CeO2 pretreated in H2. The reasons for the different activities were discussed. There were two kinds of strong metal-support interactions (SMSI) between Au and CeO2 termed as R-SMSI (pretreated in reductive atmosphere) and O-SMSI (pretreated in oxidation atmosphere). Because of the smaller size of the Au and the larger contact area, both the R-SMSI and O-SMSI of E-Au/CeO2 were larger than those of Y-Au/CeO2. The O-SMSI was accompanied by the formation of cationic Au species that were beneficial to the enhancing of activity. As expected, the activity of E-Au/CeO2 pretreated in O2 with a Au size less than 5 nm was higher than that of Y-Au/CeO2 pretreated in O2 with 25 nm Au. However, it is surprisingly found that the activity of Y-Au/CeO2 pretreated in H2 with 25 nm Au was higher than that of E-Au/CeO2 pretreated in H2 with a Au size less than 5 nm. R-SMSI resulted in the formation of a AuCe alloy that had a negative effect on the activity. Compared with E-Au/CeO2 pretreated in H2, Y-Au/CeO2 pretreated in H2 exhibited a smaller relative content of the AuCe alloy, leading to a better activity of Y-Au/CeO2 pretreated in H2.

Opening of the South China Sea and upwelling of the Hainan Plume are among the most challenging issues related to the tectonic evolution of East Asia. However, when and how the Hainan Plume affected the opening of the South China Sea remains unclear. Here we investigate the geochemical and isotopic features of the ~25 Ma mid‐ocean ridge basalt (MORB) in the Kenting Mélange, southern Taiwan, ~16 Ma MORB drilled by the IODP Expedition 349, and ~9 Ma ocean island basalt‐type dredged seamount basalt. The ~25 Ma MORBs reveal a less metasomatic depleted MORB mantle‐like source. In contrast, the Miocene samples record progressive mantle enrichment and possibly signal the contribution of the Hainan Plume. We speculate that MORBs of the South China Sea which could have recorded plume‐ridge source mixing perhaps appear since ~23.8 Ma. On the contrary, the Paleocene‐Eocene ocean island basalt‐type intraplate volcanism of the South China continental margin is correlated to decompression melting of a passively upwelling fertile asthenosphere due to continental rifting.