光催化降解直接R-F染料溶液的研究

本文以TiO_2为催化剂,采用中压汞灯为光源对偶氮染料溶液进行了光催化降解的研究。研究表明,该实验能够使直接R-F偶氮染料水溶液降解脱色,该反应为动力学一级反应。染料初始浓度在50mg·L~(-1),温度在20±1℃,经20min光照,其脱色率为97.0％以上;COD_(cr)去除率为60％左右。     

纳米二氧化钛光催化降解无机污染物的研究进展

概述了光催化氧化的发展及其在环境保护方面的应用，综述了光催化氧化的机理，主要介绍了纳米二氧化钛光催化降解废水中无机污染物和去除重金属的应用。     

5种偶氮染料溶液的光催化降解实验

以TiO2为催化剂,采用中压汞灯为光源对5种偶氮染料溶液进行了光催化降解的实验研究。结果表明,在上述条件下能够使直接R-F,直接黄y-5 GL,直接耐晒翠蓝B-GL,阳离子B-2RL,直接耐晒蓝B-BRL等偶氮染料水溶液降解脱色,染料脱色为动力学一级反应。5种偶氮染料在初始浓度50mg/L,温度201℃下,经20min光照,其脱色率分别为97.01%、97.90%、88.13%、96.95%、95.74%;CODCr去除率分别为58.64%、40.61%、44.60%、44.71%、55.56%。并讨论了pH值、催化剂用量、脱色时间和染料结构等因素对脱色与降解的影响。     

恒定COD去除现象及其机理探讨

在含Cu^2 甲酸溶液的连续光催化氧化实验中，意外地观察到一个恒定的COD去除现象，归因于铜离子的光沉积和沉积铜的氧化溶解的循环过程，这一机理通过扫描电镜测试及pH值，铜离子浓度和光电流在反应过程中的涨落现象得到初步的证实。     

Comparison of the effect of hydrogen incorporation and oxygen vacancies on the properties of anatase TiO2: electronics,optical absorption,and interaction with water

Hydrogenation has been recently developed as an approach to improve the visible-light response of titanium dioxide （TiO2）; however, the effect of hydrogenation on the electronics and optical absorption of anatase TiO2 has been widely debated. In this work, the electronic structures and optical properties of hydrogenated TiO2 and its interaction with water have been studied using the density functional theory plus Hubbard model. A comparison of the effect of hydrogenation and introduction of oxygen vacancies （OVs） to TiO2 is presented. It is found that both hydrogenation and OVs can promote the absorption of visible light and strengthen the adsorption of water. Compared with OVs, hydrogen incorporation can lead to local distortion and even amorphous structures when it is heavily doped.     

Improving the photocatalytic activity of graphitic carbon nitride by thermal treatment in a high-pressure hydrogen atmosphere

Extending visible light absorption range and suppressing the recombination of photogenerated charge carriers are always important topics in developing efficient solar-driven photocatalysts. In this study, the thermal treatment process at 400 °C in a high-pressure hydrogen atmosphere was applied to modify graphitic carbon nitride. Compared to the normal atmospheric hydrogen treatment process, this process has the merit of producing nitrogen deficient graphitic carbon nitride in high-yield. The optimal photocatalytic activity of modified graphitic carbon nitride was demonstrated by controlling the treatment duration in the hydrogen atmosphere.The changes in the crystal structure, microstructure and optical properties of carbon nitrides were investigated by several characterizations. The relationship between the photocatalytic activity and structures of graphitic carbon nitride was preliminarily established. The results obtained in this study could provide some new ways of improving the activity of graphitic carbon nitride based photocatalyst.     

苯酚液相光催化氧化研究

本文研究了苯酚有机污染物的光催化降解过程，实验表明，催化剂用量，溶液ＰＨ值等都对其降解过程有较大影响，并探讨了不同光催化剂的催化活性。     

多壳层TiO2/石墨烯复合纳米材料的制备及其在光催化还原CO2中的应用

使用碳球作为模板,利用水热-煅烧的方法制备了多壳层TiO_2。以多壳层TiO_2和氧化石墨烯为原料,利用水热法制备了多壳层TiO_2/还原氧化石墨烯(r-GO)光催化剂。运用XRD,TEM,FT-IR,DRS等测试手段对制备的样品进行表征;并探究其在可见光下对光催化还原CO_2的活性。表征结果表明粒径均匀的多壳层TiO_2纳米球均匀地分布在r-GO表面,r-GO的引入拓宽了光响应的范围。光催化结果表明,复合r-GO后TiO_2的光催化性能显著地提升。     

ZnO nanofluids - A potential antibacterial agent

In this work, ZnO nanofluids were produced by a medium mill with a pH value of about 7.2 and characterized by Nano-Sizer and SEM. After milling, ZnO nanofluids were formed with an average particle size of～198.4 nm. The ZnO nanofluids used for testing were stored for different periods (1-, 90- and 120-day) and kept in different conditions (under the light and in the dark). The antibacterial activ- ities of these ZnO nanofluids were evaluated by estimating the reduction ratio of the bacteria treated with ZnO. The results showed that the ZnO nanofluid stored for 120 days under the light had the best antibacterial behavior against Escherichia coli DH5α. SEM images suggest that an interaction between the ZnO particles and the E. Coli bacteria cells caused by electrostatic forces might be a mechanism.     

Noble-metal-free MoS2/Ta3N5 heterostructure photocatalyst for hydrogen generation

A noble-metal-free heterostructure composed of Ta_3N_5 nanosheets and MoS_2 co-catalyst was developed as an efficient photocatalyst for hydrogen production. In special, the MoS_2/Ta_3N_5 heterostructure with 5.2 wt% of MoS_2 exhibits a H_2 generation rate of 119.4 μmol h~(-1) g-1, which is comparable to that of Ta_3N_5 nanosheets with Pt as co-catalyst. The efficient H2 generation for MoS_2/Ta3N5 heterostructure is resulted from the short diffusion distance of photo-excited charge carriers in Ta3 N5 nanosheets, efficient transfer of electrons from Ta3 N5 nanosheets to MoS_2 surface, and reduced overpotential for water reduction. Furthermore, the stability of the MoS_2/Ta_3N_5 heterostructured photocatalysts are evaluated for the photocatalytic H_2 generation.