The activity of Co-SrTiO3 for photocatalytic decomposition of water into hydr ogen was studied, and the reason for improvement of activity of supported cataly sts by first reduction in H2 at a higher temperature and t...The activity of Co-SrTiO3 for photocatalytic decomposition of water into hydr ogen was studied, and the reason for improvement of activity of supported cataly sts by first reduction in H2 at a higher temperature and then reoxidation in oxy gen at a lower temperature was analyzed. The mechanism of the photocatalysis of Co-SrTiO3-R-O and Ni-SrTiO3-R-O catalyst was investigated. The metal, Ni o r Co deposited at the interface between the P-type semiconductor, NiO or CoO, a nd the N-type semiconductor, SiTiO3, which may act as the trapped site of elect ron and hole from the N-type semiconductor and the P-type semiconductor respec tively, suppresses the recombination of electron and hole in the bulk of semicon ductor, and furthermore increase the catalytic activity of the catalyst. A highe r activity of Co-SrTiO3-R-O for water decomposition than that of Ni-SrTiO3- R-O is mainly due to CoO having a narrower band gap and a wider range of light absorbance, compared with NiO.展开更多
A new citrate acid-hydrazine sol-gel route for preparation of Co3O4 nanoparticles has been developed. Co3O4 nanoparticles with different particle-sizes and morphology were prepared at different heat-treatment temperat...A new citrate acid-hydrazine sol-gel route for preparation of Co3O4 nanoparticles has been developed. Co3O4 nanoparticles with different particle-sizes and morphology were prepared at different heat-treatment temperatures and the pure cubic nanocrystals of Co3O4 were obtained at 600℃. The synthesis process was monitored by infrared spectroscopy (IR), thermal gravimetric and differential thermal analysis (TG-DTA). The structure and morphology of Co3O4 nanocrystals were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and X-ray-photoelectron spectroscopy (XPS). The infrared absorption bands blue-shifted with particle size decreasing, which could be attributed to increasing surface effect. XPS results showed that predominant species at surface layers of Co3O4 nanocrystals are octahedral Co (Ⅲ).展开更多
文摘The activity of Co-SrTiO3 for photocatalytic decomposition of water into hydr ogen was studied, and the reason for improvement of activity of supported cataly sts by first reduction in H2 at a higher temperature and then reoxidation in oxy gen at a lower temperature was analyzed. The mechanism of the photocatalysis of Co-SrTiO3-R-O and Ni-SrTiO3-R-O catalyst was investigated. The metal, Ni o r Co deposited at the interface between the P-type semiconductor, NiO or CoO, a nd the N-type semiconductor, SiTiO3, which may act as the trapped site of elect ron and hole from the N-type semiconductor and the P-type semiconductor respec tively, suppresses the recombination of electron and hole in the bulk of semicon ductor, and furthermore increase the catalytic activity of the catalyst. A highe r activity of Co-SrTiO3-R-O for water decomposition than that of Ni-SrTiO3- R-O is mainly due to CoO having a narrower band gap and a wider range of light absorbance, compared with NiO.
基金This work was financially supported by the Program of International Cooperation of Science & Technology between China and Ukraine (No. 043-05)the Joint Program between the Educational Committee and Economic Trade Committee of Gansu Provience (No. CX-
文摘A new citrate acid-hydrazine sol-gel route for preparation of Co3O4 nanoparticles has been developed. Co3O4 nanoparticles with different particle-sizes and morphology were prepared at different heat-treatment temperatures and the pure cubic nanocrystals of Co3O4 were obtained at 600℃. The synthesis process was monitored by infrared spectroscopy (IR), thermal gravimetric and differential thermal analysis (TG-DTA). The structure and morphology of Co3O4 nanocrystals were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and X-ray-photoelectron spectroscopy (XPS). The infrared absorption bands blue-shifted with particle size decreasing, which could be attributed to increasing surface effect. XPS results showed that predominant species at surface layers of Co3O4 nanocrystals are octahedral Co (Ⅲ).
