In this paper, porous silicon/V205 nanorod composites are prepared by a heating process of as-sputtered V film on porous silicon (PS) at 600 ℃ for different times (15, 30, and 45 min) in air. The morphologies and...In this paper, porous silicon/V205 nanorod composites are prepared by a heating process of as-sputtered V film on porous silicon (PS) at 600 ℃ for different times (15, 30, and 45 min) in air. The morphologies and crystal structures of the samples are investigated by field emission scanning electron microscope (FESEM), x-ray diffractometer (XRD), x-ray photoelectron spectroscopy (XPS), and Raman spectrum (RS). An improved understanding of the growth process of V205 nanorods on PS is presented. The gas sensing properties of samples are measured for NO2 gas of 0.25 ppm-3 ppm at 25 ℃. We investigate the effects of the annealing time on the NO2-sensing performances of the samples. The sample obtained at 600 ℃ for 30 min exhibits a very strong response and fast response-recovery rate to ppm level NO2, indicating a p-type semiconducting behavior. The XPS analysis reveals that the heating process for 30 rain produces the biggest number of oxygen vacancies in the nanorods, which is highly beneficial to gas sensing. The significant NO2 sensing performance of the sample obtained at 600 ℃ for 30 rain probably is due to the strong amplification effect of the heterojunction between PS and V205 and a large number of oxygen vacancies in the nanorods.展开更多
Through one-step simple polyol-assisted (ethylene glycol) process, V2O5 hollow mi-cro-spheres about 3 micrometres in size were successfully synthesized. The structure is neat, the outer wall were porous. Testing its e...Through one-step simple polyol-assisted (ethylene glycol) process, V2O5 hollow mi-cro-spheres about 3 micrometres in size were successfully synthesized. The structure is neat, the outer wall were porous. Testing its electrochemical properties with V2O5 hollow materials as cathode materia of lithium ion battery, the results showed that under the ratio of 1 C, the initial charge and discharge specific capacity were 236.8 mAh g^-1, 213 mAh g^-1, even if after 100 cycles, the charge and discharge specific capacity were still 220 mAh g^-1 and 219.7 mAh g^-1 respectively. Relative to the charge and discharge capacity of the second cycle, the keep rate were 93.2%, 92.9% respectively, has good cycle stability.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61271070,61274074,and 61574100)
文摘In this paper, porous silicon/V205 nanorod composites are prepared by a heating process of as-sputtered V film on porous silicon (PS) at 600 ℃ for different times (15, 30, and 45 min) in air. The morphologies and crystal structures of the samples are investigated by field emission scanning electron microscope (FESEM), x-ray diffractometer (XRD), x-ray photoelectron spectroscopy (XPS), and Raman spectrum (RS). An improved understanding of the growth process of V205 nanorods on PS is presented. The gas sensing properties of samples are measured for NO2 gas of 0.25 ppm-3 ppm at 25 ℃. We investigate the effects of the annealing time on the NO2-sensing performances of the samples. The sample obtained at 600 ℃ for 30 min exhibits a very strong response and fast response-recovery rate to ppm level NO2, indicating a p-type semiconducting behavior. The XPS analysis reveals that the heating process for 30 rain produces the biggest number of oxygen vacancies in the nanorods, which is highly beneficial to gas sensing. The significant NO2 sensing performance of the sample obtained at 600 ℃ for 30 rain probably is due to the strong amplification effect of the heterojunction between PS and V205 and a large number of oxygen vacancies in the nanorods.
文摘Through one-step simple polyol-assisted (ethylene glycol) process, V2O5 hollow mi-cro-spheres about 3 micrometres in size were successfully synthesized. The structure is neat, the outer wall were porous. Testing its electrochemical properties with V2O5 hollow materials as cathode materia of lithium ion battery, the results showed that under the ratio of 1 C, the initial charge and discharge specific capacity were 236.8 mAh g^-1, 213 mAh g^-1, even if after 100 cycles, the charge and discharge specific capacity were still 220 mAh g^-1 and 219.7 mAh g^-1 respectively. Relative to the charge and discharge capacity of the second cycle, the keep rate were 93.2%, 92.9% respectively, has good cycle stability.