非贵金属修饰的光催化剂制备及其产氢性能研究

发布时间：2018-03-18 10:47

本文选题：光催化　切入点：氢能　出处：《上海交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：能源危机和环境问题被认为是当今阻碍人类发展的两大主要因素。光催化的手段能够将太阳能转化为清洁能源——氢能,而且其转化过程简单,被认为具有很大的发展潜力缓解这两大阻碍。考虑到目前高效的光催化剂因需要贵金属的修饰而成本过高,本文采用廉价金属Cu、Ni对传统半导体催化材料TiO2和CdS进行修饰改性,并且制备无需助催化剂的层状化合物,得到催化活性高且稳定性较好的催化剂,并对其光催化分解水产氢性能进行了研究。本文考查了Cu系物种负载对TiO2光催化产氢活性的影响。以P25为载体,采用水热还原法、浸渍焙烧法以及浸渍焙烧还原法分别制备得到负载了Cu或其氧化物的催化剂。通过XRD、UV-Vis DRS、BET以及TEM测试手段分析不同制备方法得到的Cu系物种修饰对催化剂晶型、能带结构、表面以及孔结构等的影响,讨论了不同Cu系物种负载对P25光催化产氢性能的影响。采用水热还原法制备了表面负载金属镍单质的硫化镉光催化剂。通过XRD、UV-Vis DRS、BET、TEM、XPS等表征手段对所制备催化剂的化学组成、能带结构、孔结构、表面性质变化等进行表征,并对不同负载量的催化剂进行了活性测试。研究发现,当采用10 vol%乳酸为牺牲剂时,负载5 wt%镍的硫化镉光催化产氢活性相比单纯的硫化镉提高了5倍,甚至优于负载0.5 wt%铂作为助催化剂的样品。通过XPS等表征手段发现镍在乳酸中发挥着与其他传统的牺牲剂不同的作用。通过柠檬酸络合法制备了无贵金属的层状钙钛矿型的K0.5La0.5Bi2Ta2O9,并通过质子化得到H-K0.5La0.5Bi2Ta2O9。通过ICP、XRD、TEM、UV-Vis DRS等表征手段考察所制备催化剂的化学组成、材料形貌、晶体结构以及光吸收性能等,考察了不同合成温度以及牺牲剂对H-K0.5La0.5Bi2Ta2O9产氢活性的影响。结果表明:这种层状化合物在没有助催化剂和牺牲剂条件下即具有较高活性,其光解水产氢量达到232.6μmol·h~-1。
[Abstract]:The energy crisis and environmental problems are considered two major obstacles to human development today. Photocatalytic means can convert solar energy into clean energy-hydrogen energy, and the conversion process is simple. It is considered that there is great development potential to alleviate these two obstacles. Considering the high cost of high efficient photocatalyst due to the need of noble metal modification, the cheap metal Cu-Ni is used to modify the traditional semiconductor catalytic materials TiO2 and CdS. In addition, the layered compounds without catalyst were prepared, and the catalyst with high catalytic activity and good stability was obtained. The effect of Cu species loading on the photocatalytic hydrogen production activity of TiO2 was studied. Using P25 as carrier, hydrothermal reduction method was used. The catalysts supported on Cu or their oxides were prepared by impregnation roasting and dipping roasting reduction methods respectively. The crystal structure and energy band structure of the catalysts were analyzed by XRDX UV-Vis DRSET and TEM measurements. The influence of surface and pore structure, etc., The effect of different Cu species on the photocatalytic hydrogen production of P25 was discussed. The surface supported nickel cadmium sulfide photocatalyst was prepared by hydrothermal reduction method. The chemical composition of the prepared catalyst was characterized by XRDX UV-Vis DRSU BETTEMXPS. The energy band structure, pore structure and surface properties were characterized. The activity of the catalysts with different loading amounts was tested. It was found that 10 volt% lactic acid was used as the sacrificial agent. The photocatalytic activity of cadmium sulfide loaded with 5wt% nickel is 5 times higher than that of cadmium sulfide alone. It is found by XPS that nickel plays a different role from other traditional sacrificial agents in lactic acid. The layered layer without precious metal is prepared by citric acid complexation. Perovskite K0.5La0.5Bi2Ta2O9 was obtained by protonation of H-K0.5La0.5Bi2Ta2O9.The chemical composition of the catalyst was investigated by means of ICP-XRDX Tem DRS and UV-Vis DRS. The effects of different synthesis temperature and sacrificial agent on the hydrogen production activity of H-K0.5La0.5Bi2Ta2O9 were investigated. The results showed that the layered compound had high activity without catalyst and sacrificial agent. The amount of hydrogen in hydrolysate reached 232.6 渭 mol 路hm-1.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.36;TQ116.2

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