Cuprous oxide micro-/nanocrystals were synthesized by using a simple liquid phase reduction process under microwave irradiation. Copper sulfate was used as the starting materials and macromolecule surfactants served a...Cuprous oxide micro-/nanocrystals were synthesized by using a simple liquid phase reduction process under microwave irradiation. Copper sulfate was used as the starting materials and macromolecule surfactants served as the templates. The morphologies phase and optical properties of them are characterized by X-ray diffraction （XRD）, scanning elec- tron microscopy （SEM） and ultraviolet-visible diffuse reflection absorptive spectra （UV-vis/DRS）, respectively. The crystals had four different shapes, namely spheres, strips, octahedrons, and dandelions. The photocatalytic behavior of the cuprous oxide particles were investigated by monitoring the degradation of rhodamine B. In spite of the differ- ent morphologies, all of the cuprous oxide micro-/nanocrystals exhibited photocatalytic activities under visible light irradiation in the following order： dandelions, strips, spheres, and octahedral crystals. The photocatalytic degradation rates of rhodamine B are 56.37%, 55.68%, 51.83% and 46.16%, respectively. The morphology affects significantly the photocatalytic performance.展开更多
The effect of surface mechanical attrition treatment （SMAT） of commercially pure titanium （CP-Ti） using 8 mm O alumina balls was studied. SMAT induced plastic deformation, increased the surface roughness, reduced ...The effect of surface mechanical attrition treatment （SMAT） of commercially pure titanium （CP-Ti） using 8 mm O alumina balls was studied. SMAT induced plastic deformation, increased the surface roughness, reduced the grain size and decreased the contact angle （from 64° to 43°） with a corresponding increase in surface energy （from 32 to 53 mJ/m2）. Untreated CP-Ti and those treateded using alumina bails for 900 s reveals no apatite growth until the 28th day of immersion whereas those treated for 1800 and 2700 s exhibit apatite growth In selective areas and the extent of growth is increased with increase in immersion time an SBF; The study reveals that SMAT using alumina balls is beneficial in imparting the desired surface Cheracteristics, provided the surface contamination is limited, which would otherwise decrease the apatite forming ability.展开更多
Due to a large surface-to-volume ratio, the optoelectronic performance of low- dimensional semiconductor nanostructure-based photodetectors depends in principle on chemisorption/photodesorption at the exposed surface,...Due to a large surface-to-volume ratio, the optoelectronic performance of low- dimensional semiconductor nanostructure-based photodetectors depends in principle on chemisorption/photodesorption at the exposed surface, but practical examples that show such an effect are still unavailable. Some theoretical calculations have predicted that the {001} facets of In2O3 can effectively accumulate photogenerated holes under irradiation, providing a model material to examine whether the facet cutting of nanowires （NWs） can boost their optoelectronic performance. Herein, we present the design and construction of a novel nanowire-based photodetector using square In2O3 NWs with four exposed {001} crystal facets. The photodetector delivers excellent optoelectronic performance with excellent repeatability, fast response speed, high spectral responsivity （Rλ）, and high external quantum efficiency （EQE）. The Rλ and EQE values are as high as 4.8 × 10^6 A/W and 1.46 × 10^9%, respectively, which are larger than those of other popular semiconductor photodetectors. In addition, the square In2O3 NWs show hydrophobic wettability as manifested by a contact angle of 118° and a fast photoinduced reversible switching behavior is observed.展开更多
基金Acknowledgements The work was financially supported by the National Natural Science Foundation of China （Grant Nos. 31000430 and 51201192） and the Science and Technology Development Program of Chongqing Science and Technology Commission （cstc2012gg-yyjs0224）.
基金supported by the Open Foundation of National Laboratory of Mineral Materials of China University of Geosciences (Grant No. 08A006)the Key Project of Chinese Ministry of Education (No. 107023)+1 种基金Special Fund of Co-construction of Beijing Education CommitteeCity University of Hong Kong Strategic Research Grant (SRG) No. 7008009
文摘Cuprous oxide micro-/nanocrystals were synthesized by using a simple liquid phase reduction process under microwave irradiation. Copper sulfate was used as the starting materials and macromolecule surfactants served as the templates. The morphologies phase and optical properties of them are characterized by X-ray diffraction （XRD）, scanning elec- tron microscopy （SEM） and ultraviolet-visible diffuse reflection absorptive spectra （UV-vis/DRS）, respectively. The crystals had four different shapes, namely spheres, strips, octahedrons, and dandelions. The photocatalytic behavior of the cuprous oxide particles were investigated by monitoring the degradation of rhodamine B. In spite of the differ- ent morphologies, all of the cuprous oxide micro-/nanocrystals exhibited photocatalytic activities under visible light irradiation in the following order： dandelions, strips, spheres, and octahedral crystals. The photocatalytic degradation rates of rhodamine B are 56.37%, 55.68%, 51.83% and 46.16%, respectively. The morphology affects significantly the photocatalytic performance.
文摘The effect of surface mechanical attrition treatment （SMAT） of commercially pure titanium （CP-Ti） using 8 mm O alumina balls was studied. SMAT induced plastic deformation, increased the surface roughness, reduced the grain size and decreased the contact angle （from 64° to 43°） with a corresponding increase in surface energy （from 32 to 53 mJ/m2）. Untreated CP-Ti and those treateded using alumina bails for 900 s reveals no apatite growth until the 28th day of immersion whereas those treated for 1800 and 2700 s exhibit apatite growth In selective areas and the extent of growth is increased with increase in immersion time an SBF; The study reveals that SMAT using alumina balls is beneficial in imparting the desired surface Cheracteristics, provided the surface contamination is limited, which would otherwise decrease the apatite forming ability.
基金This work was supported by the National Basic Research Program of China （Nos. 2014CB339800 and 2013CB932901） and National Natural Science Foundation of China （Nos. 11374141, 61264008, 21203098 and 21375067）. Partial support was provided by City University of Hong Kong Applied Research Grant （ARG） （No. 9667122）.
文摘Due to a large surface-to-volume ratio, the optoelectronic performance of low- dimensional semiconductor nanostructure-based photodetectors depends in principle on chemisorption/photodesorption at the exposed surface, but practical examples that show such an effect are still unavailable. Some theoretical calculations have predicted that the {001} facets of In2O3 can effectively accumulate photogenerated holes under irradiation, providing a model material to examine whether the facet cutting of nanowires （NWs） can boost their optoelectronic performance. Herein, we present the design and construction of a novel nanowire-based photodetector using square In2O3 NWs with four exposed {001} crystal facets. The photodetector delivers excellent optoelectronic performance with excellent repeatability, fast response speed, high spectral responsivity （Rλ）, and high external quantum efficiency （EQE）. The Rλ and EQE values are as high as 4.8 × 10^6 A/W and 1.46 × 10^9%, respectively, which are larger than those of other popular semiconductor photodetectors. In addition, the square In2O3 NWs show hydrophobic wettability as manifested by a contact angle of 118° and a fast photoinduced reversible switching behavior is observed.
