本文采用热聚合法和水热法成功制备了ZnO/g-C3N4系列复合光催化剂, 并对所制备样品的结构、形貌和光吸收性能等进行了表征和测试, 通过在可见光照射下降解亚甲基蓝(MB)和光解水产氢评估了样品的光催化性能。实验结果表明, 制备的ZnO/g-C3N4系列复合光催化剂性能均优于ZnO和g-C3N4样品。此外, 当ZnO和g-C3N4的摩尔比为1∶1时, 所制备ZnO/g-C3N4复合样品的光催化性能最好。一方面, 此样品仅在30 min后便达到了94.36%的降解率, 其降解速率分别是ZnO和g-C3N4的5.6和6.7倍; 另一方面, 此样品6 h光解水产氢量为11.75 mmol, 产氢速率是g-C3N4的7倍。研究表明, 所制备的ZnO/g-C3N4系列复合光催化剂在降解污染物和光解水产氢方面均展现出了优异的性能。同时, 本文还对ZnO/g-C3N4系列复合光催化剂的光催化降解和产氢机理进行了研究。

利用脱铁铁蛋白制备的纳米材料具有尺寸可控、单一等优点, 在催化方面同样具有很大优势。本文以脱铁铁蛋白为模板, 硒脲为硒源, 乙酸铵与乙酸铅为原料, 通过模板合成法和两步法制备脱铁铁蛋白/硒化铅(apo/PbSe)复合材料, 采用透射电子显微镜(TEM)、X射线衍射仪(XRD)、X射线能谱仪(EDS)、紫外-可见分光光度计(UV-vis)、荧光光谱仪(PL)等手段分析材料, 并测定了apo/PbSe复合材料在可见光下对废水染料甲基橙的催化降解性能。结果表明, 蛋白质内部的矿物核心主要物质为PbSe, 成功合成了apo/PbSe复合光催化剂。复合光催化剂的最佳实验条件为溶液pH=3.0, H2O2质量分数9%, 此时对甲基橙的降解效率最高可达97.10%, 五次循环降解实验证明了其光催化效率的稳定性。基于以上结果, 说明apo/PbSe具有良好的催化活性和稳定性, 并提出了apo/PbSe复合材料对甲基橙的光催化降解机理。

Currently, supra-wavelength periodic surface structures (SWPSS) are only achievable on silica dielectrics and silicon by femtosecond (fs) laser ablation, while triangular and rhombic laser induced periodic surface structures (LIPSS) are achievable by circularly polarized or linear cross-polarized femtosecond laser. This is the first work to demonstrate the possibility of generating SWPSS on Sn and triangular and rhombic LIPSS on W, Mo, Ta, and Nb using a single linearly polarized femtosecond laser. We discovered, for the first time, SWPSS patches with each possessing its own orientation, which are completely independent of the light polarization direction, thus, breaking the traditional rules. Increasing the laser power enlarges SWPSS periods from 4-6 μm to 15-25 μm. We report a maximal period of 25 μm, which is the largest period ever reported for SWPSS, ～10 and ～4 times the maximal periods (2.4 μm/6.5 μm) of SWPSS ever achieved by fs and ns laser ablation, respectively. The formation of triangular and rhombic LIPSS does not depend on the laser (power) or processing (scan interval and scan methodology) parameters but strongly depends on the material composition and is unachievable on other metals, such as Sn, Al, Ti, Zn, and Zr. This paper proposes and discusses possible mechanisms for molten droplet generation/spread/solidification, Marangoni convection flow for SWPSS formation, and linear-to-circular polarization transition for triangular and rhombic LIPSS formation. Reflectance and iridescence of as-prepared SWPSS and LIPSS are characterized. It was found that besides insufficient ablation on W, the iridescence density of Ta-, Mo-, Nb-LIPSS follows the sequence of melting temperatures: Ta > Mo > Nb, which indicates that the melting temperature of metals may affect the regularity of LIPSS. This work may inspire significant interest in further enriching the diversity of LIPSS and SWPSS.