【作者】 张鹏；

【导师】 贾立山；

【作者基本信息】 厦门大学 ， 工业催化， 2008， 硕士

【摘要】 利用太阳能光催化分解水制氢是从长远角度解决人类当前严峻的能源问题和环境问题的一条重要途径。TiO₂被认为是最有希望的光催化材料,但是光催化分解水制氢速率较低,可见光响应差的缺点限制了它的大规模应用。本文以提高TiO₂光催化水分解制氢催化效率和研制在可见光下具有更高光催化水分解产氢活性的光催化材料为目的,考察了不同体系中影响TiO₂产氢速率的因素,混晶比的影响和控制,微生物法掺碳改性TiO₂的可见光催化活性,新的可见光制氢材料La₂O₂（CO₃）-基CoO/Ni制备和光催化性能研究,得到以下研究结果:1、在分别以Na₂S和甲醛为牺牲剂体系下光催化分解水制氢中反应温度对Pt/TiO₂催化剂产氢速率有显著影响:提高反应温度大大提高产氢速率,其机理分析表明,提高温度促进了Na₂S水解进而促进了光化学产氢,而甲醛为牺牲剂时主要是由于抑制了逆反应的进行。2、通过控制焙烧温度制备不同金红石含量的混晶TiO₂,考察了金红石含量的影响,并进行了机理分析。为了解决粒径变化的影响,对溶胶凝胶法进行了改进,首次采用TiCl₄和钛酸四正丁酯混合物作前驱体的方法获得了粒径均匀混晶比可控的纳米TiO₂,对其光催化分解水制氢活性评价后发现其规律证实了提出的机理。3、为了获得高活性可见光响应的分解水制氢光催化剂,采用Fe对TiO₂进行了掺杂,并对其特性及其氙灯照射下的光催化活性进行了考察。结果发现,Fe提高了TiO₂对可见光的吸收,提高了TiO₂可见光分解水制氢活性,掺Fe 2（wt）%的TiO₂活性最佳,可达到3.67μmol/（gcat·h）。4、首次采用菌粉浸出液改性的方法成功制备了掺C-TiO₂,对其结构进行了表征分析,对其氙灯照射下光催化分解水制氢活性考察。结果发现,C掺杂促进了TiO₂对波长大于400nm的光的吸收,当菌液浓度为6.33g/L时,引入了5.657%（原子比）的C,其可见光下光催化分解水制氢速率可达10.29μmol/（gcat·h）。5、制备了一系列La₂O₂（CO₃）-基CoO/Ni混晶催化剂并首次将其用于可见光催化分解水制氢,结果发现,氙灯照射下La₂O₂（CO₃）-CoO-3h样品产氢活性高达31.62μmol/（gcat·h）,与Ni的混晶获得了更高的可见光催化分解水制氢活性,La₂O₂（CO₃）-Ni-3h样品产氢活性高达84.90μmol/（gcat·h）。对其结构进行了表征,对其机理进行了初步分析。更多还原

【Abstract】 Photocatalytic water splitting using solar energy has received a great deal of attention since it has been considered as one of the potential ways to provide clean and renewable energy of H₂.Among the photocatalytic materials being studied,TiO₂ is one of the most promising photocatalyst.While its application was limited for its poor efficiency of photocatalytic water splitting to H₂ and it cannot be excited by visible light.To get a higher efficiency of photocatalytic H₂ evolution over TiO₂ and find proper visible light responding water splitting photocatalytic materials,this thesis investigated the factors affect the photocatalytic activity of TiO₂,the influence of rutile phase content in nano-TiO₂,the photocatalytic H₂ evolution over C doped-TiO₂ prepared by bacillus licheniformis（R08） leaching solution modifying,the preparation and photocatalytic activity of new type visible light responding photocatalytic water splitting material La₂O₂（CO₃）-based CoO/Ni,which are as follows,1.Photocatalytic H₂ evolution over Pt/TiO₂ by water splitting as Na₂S or formaldehyde being present as sacrificial reagents were influence markedly by reaction temperature:the rate of H₂ evolution increased quickly with reaction temperature.The possible reaction mechanism shows that increasing of temperature accelerated the hydrolysis of Na₂S and thus accelerated the photochemical H₂ evolution,while it inhibited the reverse reaction as formaldehyde was used.2.Nano-TiO₂ samples with various content of rutile were prepared by adjusting the baking temperature.The effect of rutile content was investigated and possible mechanism was suggested.To avoid the influence of particle size,a novel method which take the mixture of TiCl₄ and Ti（OC₄H₉）₄ as precursor was applied and rutile content-controllable nano-TiO₂ samples with even particle size were synthesized.Their photocatalytic activity confirmed the mechanism.3.To get higher photocatalytic activity under visible light irradiation for water splitting,Fe doped TiO₂ were synthesized and characterized,and their activity were determined.The results show that,Fe improve the absorption of TiO₂ on visible light markedly,and promote the H₂ evolution.As 2（wt）%Fe was doped,the optimal activity got which is 3.67μmol/（gcat·h）.4.C doped-TiO₂ samples were successfully synthesized by R08 leaching solution modifying and their structures were characterized.As xenon lamp was used,the activity of C doped-TiO₂ samples were determined.The results show that doping of C enhanced the absorption on the light with wavelength＞400nm of TiO₂.As 6.33 g/L R08 leaching solution was used,5.657%（atom） of C was introduced,and the rate of H₂ evolution over the modified TiO₂ under irradiation of xenon lamp reached to 10.29μmol/（gcat·h）.5.A series of La₂O₂（CO₃）-based CoO/Ni catalysts were prepared and their photocatalytic activities of water splitting to H₂ under visible light irradiation were determined.The rate of H₂ evolution over La₂O₂（CO₃）-CoO-3h under xenon lamp irradiation reached to 31.62μmol/（gcat·h）.The composite photocatalyst with Ni showed higher activity,the rate of H₂ evolution over La₂O₂（CO3）-Ni-3h reached to 84.90μmol/（gcat·h）.The structures of La₂O₂（CO₃）-based CoO/Ni catalysts were characterized and the mechanism was analyzed.更多还原