Ramya R, Krishnan P Santhana, Neelaveni M, Gurulakshmi M, Sivakumar T, Shanthi K
Department of Chemistry, Anna University, Chennai 600025, India.
Department of Applied Science and Technology, A.C. Tech., Anna University, Chennai 25, India.
J Nanosci Nanotechnol. 2019 Jul 1;19(7):3971-3981. doi: 10.1166/jnn.2019.16308.
A facile hydrothermal method was adopted for the synthesis of bare TiO₂ and titania nanotubes (TNT). In an effort to increase the efficacy of the existing photocatalyst, different weight percentage (0.2, 0.4, 0.6, 0.8 and 1.0%) of praseodymium were deftly doped on to the synthesized titania scaffolds. The physicochemical characteristics of the architectured photocatalyst were thoroughly elucidated by various sophisticated techniques. The doping of Pr₂O₃ (Pr) on to titania nanotubes (TNT) resulted into a significant bathochromic/hyperchromic shift in the optical absorption edge (towards the visible region) as perceived from the DRS-UV spectra. The XRD and TEM analysis showed average crystallite size of the synthesised photocatalyst to be as small as 4-7 nm with well-formed nanotube framework. Photoluminescence spectra of Pr doped TNT catalyst clearly exhibited greater suppression of photogenerated electron-hole pair as compared to the undoped counterparts. The photocatalytic activity of the synthesized catalysts was evaluated towards the degradation of organic pollutants namely Rhodamine B (90%) and Crystal violet (93%) in the presence of solar light and its activity and durability was compared to that of commercial TiO₂ (Degussa P25). The observed enhanced photocatalytic activity of TNT and Pr-TNT can be unambiguously attributed to the inhibition of recombination of the electron-hole pairs due to doping of Pr into TNT. Among catalysts synthesized, 0.4 wt.% of Pr on to TNT yielded the highest photocatalytic activity under visible light irradiation.
采用一种简便的水热法合成了裸露的TiO₂和二氧化钛纳米管（TNT）。为了提高现有光催化剂的效能，将不同重量百分比（0.2%、0.4%、0.6%、0.8%和1.0%）的镨巧妙地掺杂到合成的二氧化钛支架上。通过各种精密技术深入阐明了构建的光催化剂的物理化学特性。从DRS-UV光谱可以看出，在二氧化钛纳米管（TNT）上掺杂Pr₂O₃（Pr）导致光吸收边缘出现显著的红移/增色移（向可见光区域）。XRD和TEM分析表明，合成的光催化剂的平均微晶尺寸小至4-7nm，具有良好的纳米管框架。与未掺杂的对应物相比，Pr掺杂的TNT催化剂的光致发光光谱清楚地显示出对光生电子-空穴对的更大抑制。在太阳光存在下，评估了合成催化剂对有机污染物罗丹明B（90%）和结晶紫（93%）的光催化降解活性，并将其活性和耐久性与商业TiO₂（Degussa P25）进行了比较。观察到的TNT和Pr-TNT增强光催化活性可以明确归因于Pr掺杂到TNT中对电子-空穴对复合的抑制。在合成的催化剂中，TNT上0.4wt.%的Pr在可见光照射下产生最高的光催化活性。
