Sulfur doped anatase TiO2 nanoparticles （3 nm- 12 nm） were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photoc...Sulfur doped anatase TiO2 nanoparticles （3 nm- 12 nm） were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photocatalytic properties of the synthesized sulfur doped TiO2 nanoparticles were studied along with Degussa commercial TiO2 particles （24 nm）. The results show that band gap of TiO2 particles decreases from 3.31 to 3.25 eV and for that of commercial TiO2 to 3.2 eV when the particle sizes increased from 3 nm to 12 nm with increase in sulfur doping. The results of the photocatalytic activity under UV and sun radiation show maximum phenol conversion at the particle size of 4 nm at 4.80% S-doping. Similar results are obtained using UV energy for both phenol conversion and conversion of CO2＋H2O in which formation of methanol, ethanol and proponal is observed. Production of methanol is also achieved on samples with a particle size of 8 and 12 nm and sulfur doping of 4.80% and 5.26%. For TiO2 particle of 4 nm without S doping, the production of methanol, ethanol and proponal was lower as compared to the S-doped particles. This is attributed to the combined electronic effect and band gap change, S dopant, specific surface area and the light source used.展开更多
Nanostructured Mg–Ni alloy with the particle size in the range of 40–50 nm was synthesized by the thermal decomposition of bipyridyl complexes of Mg and Ni metals at 773 K for 24 h under dry argon gas ambient. The a...Nanostructured Mg–Ni alloy with the particle size in the range of 40–50 nm was synthesized by the thermal decomposition of bipyridyl complexes of Mg and Ni metals at 773 K for 24 h under dry argon gas ambient. The as-prepared nano-alloy was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） for compositional and structural analysis. The alloy exhibited superior hydrogen absorption and desorption behavior with 3.2 wt% absorption within 1 min at 573 K and about 3 wt% desorption within 5–10 min at 573 K. This favorable behavior of Mg–Ni compound for the hydrogen storage is due to the specific nanostructure of the material. The low activation energy values and favorable thermodynamics indicate that the prepared Mg–Ni alloy is an attracting material for hydrogen storage applications.展开更多
文摘Sulfur doped anatase TiO2 nanoparticles （3 nm- 12 nm） were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photocatalytic properties of the synthesized sulfur doped TiO2 nanoparticles were studied along with Degussa commercial TiO2 particles （24 nm）. The results show that band gap of TiO2 particles decreases from 3.31 to 3.25 eV and for that of commercial TiO2 to 3.2 eV when the particle sizes increased from 3 nm to 12 nm with increase in sulfur doping. The results of the photocatalytic activity under UV and sun radiation show maximum phenol conversion at the particle size of 4 nm at 4.80% S-doping. Similar results are obtained using UV energy for both phenol conversion and conversion of CO2＋H2O in which formation of methanol, ethanol and proponal is observed. Production of methanol is also achieved on samples with a particle size of 8 and 12 nm and sulfur doping of 4.80% and 5.26%. For TiO2 particle of 4 nm without S doping, the production of methanol, ethanol and proponal was lower as compared to the S-doped particles. This is attributed to the combined electronic effect and band gap change, S dopant, specific surface area and the light source used.
基金supported by Higher Education Commission (HEC), Islamabad, Pakistan under PhD indigenous-5000 Fellowship Program
文摘Nanostructured Mg–Ni alloy with the particle size in the range of 40–50 nm was synthesized by the thermal decomposition of bipyridyl complexes of Mg and Ni metals at 773 K for 24 h under dry argon gas ambient. The as-prepared nano-alloy was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） for compositional and structural analysis. The alloy exhibited superior hydrogen absorption and desorption behavior with 3.2 wt% absorption within 1 min at 573 K and about 3 wt% desorption within 5–10 min at 573 K. This favorable behavior of Mg–Ni compound for the hydrogen storage is due to the specific nanostructure of the material. The low activation energy values and favorable thermodynamics indicate that the prepared Mg–Ni alloy is an attracting material for hydrogen storage applications.
