Lixia Yang

Low-temperature, facile fabrication of ultrafine Cu2O networks by anodization on TiO2?nanotube arrays

A green and facile process was developed to fabricate ultrafine p-type Cu2O single crystal nanowires by anodizing copper (Cu0) particles preloaded on TiO2?nanotube arrays. The Cu2O nanowires with a diameter of less than 5?nm were assembled on the top surface of n-type TiO2?nanotube arrays, constructing a novel p?n junction heterostructure with larger specific surface area compared to the unmodified TiO2?nanotube arrays. X-ray diffractometer (XRD) and high-resolution transmission electron microscopy (HRTEM) were employed to demonstrate that the resulting Cu2O was single crystalline. The composite Cu2O/TiO2?nanotube arrays exhibited significantly enhanced response to the visible light, resulting from Cu2O with a narrow-band gap. Furthermore, under visible light irradiation, enhanced efficiency in separating photogenerated hole?electron pairs was achieved due to the potential difference generated on the p?n interface. A possible mechanism was proposed to explain the formation of crystal Cu2O nanowires.

Mesoporous TiO2 with WO3 functioning as dopant and light-sensitizer: A highly efficient photocatalyst for degradation of organic compound

The suitable doping or modification on TiO2 holds promise for improving charge separation and extending light absorption range. Here, WO3 modifying reduced band gap mesoporous TiO2 (WO3/RM-TiO2) due to WO3 doping was successfully fabricated by immersing mesoporous TiO2 nanoparticles in the peroxotungstic acid sol with controllable reaction time (0-1 h). The W6+ ions were first incorporated into the TiO2 lattice to form WOTi bonds, resulting in the formation of WO3 doping TiO2. Then, WO3 nanoparticles gradually formed and attached on the TiO2 surface, constructing a novel heterojunction catalyst with WO3 serving as both dopant and light-sensitizer for TiO2. Photocatalytic activity of the resulting WO3/RM-TiO2 depends on the immersing duration in the peroxotungstic acid. The BET analysis shows that 0.5 h-WO3/RM-TiO2 has the largest pore volume of 0.491 cm3 g-1 and the highest surface area of 82.3 m2 g-1, whereas these values decline with prolonged immersing duration. As expected, the optimal efficiency in removing p-nitrophenol (PNP) is achieved over 0.5 h-WO3/RM-TiO2 under visible light irradiation, which is 2.33 times that of the unmodified M-TiO2. This should be attributed to the suitable WO3 doping and WO3 modification.

The Pt/Ni Modified TiO2 Nanotubes and its Catalytic Activity Toward Glucose

The catalytic activity of Pt/Ni/TiO2 nanotubes electrode toward glucose has been studied. Fabrication of Pt/Ni nanostructures was done in a single-bath solution through electrochemical pulse method by changing the deposition potential between -0.3 and -4 V vs. SCE, respectively. The resulting modified electrode represented high conductivity due to the effective presence of metallic components and uniform surface area caused by dispersion of Pt and Ni nanostructures. The scanning electron microscopy images also confirmed that a large amount of metals colonies were well-dispersed at the edge of the TiO2 nanotubes. In addition, the Pt/Ni TiO2 nanotubes modified electrode exhibited an excellent performance in cyclic voltammetry results by changing the concentration of glucose. The proposed electrode had a wide linear range up to 13 mM with the detection sensitivity of 230 μAmM−1 cm−2 respectively. The experiment results also revealed that the electrode exhibited good selectivity with no interference from other oxidable species.