Alpha-alumina(α-Al_2O_3) platelets were prepared via solid-state reaction using pseudo-boehmite as the starting material, while NH_4F and nano-SiO_2 were used as additives, and nitric acid was used as the binder. The...Alpha-alumina(α-Al_2O_3) platelets were prepared via solid-state reaction using pseudo-boehmite as the starting material, while NH_4F and nano-SiO_2 were used as additives, and nitric acid was used as the binder. The effect of these additives on properties of the alumina platelets was determined via scanning electron microscopy, X-ray diffraction, and measurements of the surface area and silicon content. A mechanism governing their role in the synthesis process was proposed. The results indicated that NH_4F could promote the formation of highly crystalline platelets. Addition of nano-SiO_2 could lead to increase in the diameter and reduction in the thickness of the platelets, and could also prevent their transformation to α-Al_2O_3. This addition weakened the effect of NH_4F because of the reaction of nano-SiO_2 with F-species and the formation of volatile SiF_4.展开更多
首先以Hummers法制备还原态氧化石墨烯(RGO),其次通过溶胶-凝胶法和水热法分别制备TiO_(2)和TiO_(2)/RGO复合材料,然后向硝酸银溶液滴加氨水沉淀出纳米Ag并掺杂到TiO_(2)上,再以聚乙烯吡咯烷酮(PVP)为分散剂,以RGO为基体材料,用一步水...首先以Hummers法制备还原态氧化石墨烯(RGO),其次通过溶胶-凝胶法和水热法分别制备TiO_(2)和TiO_(2)/RGO复合材料,然后向硝酸银溶液滴加氨水沉淀出纳米Ag并掺杂到TiO_(2)上,再以聚乙烯吡咯烷酮(PVP)为分散剂,以RGO为基体材料,用一步水热法合成Ag@TiO_(2)/RGO复合光催化剂。复合材料通过FT-IR、XRD、SEM、DRS和BET等进行结构、组成、形貌和孔径大小的表征。将Ag@TiO_(2)/RGO用来光催化降解罗丹明B(RhB)溶液,结果表明,0.020 g该催化剂对50 mL 5 mg/L的RhB溶液在pH值为5、室温条件下的降解效果最好;经6次循环利用后,降解率依然能达到80%。展开更多
基金supported by the Technology Development(Commission) Project of SINOPEC Catalyst Co.Ltd(Grant No.14-05-01)
文摘Alpha-alumina(α-Al_2O_3) platelets were prepared via solid-state reaction using pseudo-boehmite as the starting material, while NH_4F and nano-SiO_2 were used as additives, and nitric acid was used as the binder. The effect of these additives on properties of the alumina platelets was determined via scanning electron microscopy, X-ray diffraction, and measurements of the surface area and silicon content. A mechanism governing their role in the synthesis process was proposed. The results indicated that NH_4F could promote the formation of highly crystalline platelets. Addition of nano-SiO_2 could lead to increase in the diameter and reduction in the thickness of the platelets, and could also prevent their transformation to α-Al_2O_3. This addition weakened the effect of NH_4F because of the reaction of nano-SiO_2 with F-species and the formation of volatile SiF_4.
文摘首先以Hummers法制备还原态氧化石墨烯(RGO),其次通过溶胶-凝胶法和水热法分别制备TiO_(2)和TiO_(2)/RGO复合材料,然后向硝酸银溶液滴加氨水沉淀出纳米Ag并掺杂到TiO_(2)上,再以聚乙烯吡咯烷酮(PVP)为分散剂,以RGO为基体材料,用一步水热法合成Ag@TiO_(2)/RGO复合光催化剂。复合材料通过FT-IR、XRD、SEM、DRS和BET等进行结构、组成、形貌和孔径大小的表征。将Ag@TiO_(2)/RGO用来光催化降解罗丹明B(RhB)溶液,结果表明,0.020 g该催化剂对50 mL 5 mg/L的RhB溶液在pH值为5、室温条件下的降解效果最好;经6次循环利用后,降解率依然能达到80%。
