Xia Xuewen, Li Junqi, Chen Chaoyi, Lan Yuan-Pei, Mao Xisong, Bai Fusheng
Department of Metallurgical Engineering, College of Materials and Metallurgy, Guizhou University, Huaxi, Guiyang, Guizhou, 550025, People's Republic of China. Guizhou Province Key Laboratory of Metallurgical Engineering and Process Energy Saving, Guiyang, Guizhou, 550025, People's Republic of China.
Nanotechnology. 2021 Feb 25;32(19):195708. doi: 10.1088/1361-6528/abdf90.
Morphological tuning or additional cation doping is one of the potential and simple methods to enhance the photocatalytic properties of ceria, in which rare-earth element doped ceria nanorods (CeO-RE NRs) are expected to be a promising photocatalyst with high activity. But the optimal doping conditions, including the variety and concentration of RE elements are ambiguous, and the contribution of doped RE ions to the enhancement of photocatalytic activity needs to be further studied. In this work, we doped La, Y and Sm with a wide range of 0%-30% into CeO NRs, and investigated the phase, morphology, band gap, oxygen vacancy concentration, PL spectra and photocatalytic activity variation under different doping conditions. All synthesized CeO-RE NRs possessed a good nanorod morphology except the 15 and 30% Y-doped samples. The energy band gaps of the synthesized samples changed slightly; the 10% CeO-RE NRs with the narrowest band gaps possessed the higher photocatalytic performance. The most outstanding photocatalyst was found to be the 10% Y-doped CeO NRs with a methylene blue photodegradation ratio of 85.59% and rate constant of 0.0134 min, which is particularly associated with a significant higher oxygen vacancy concentration and obviously lower recombination rate of photogenerated e/h pairs. The doped RE ions and the promotion of oxygen vacancy generation impede the recombination of photogenerated carriers, which is proposed as the main reason to enhance the photocatalytic property of CeO.
形态调控或额外的阳离子掺杂是增强二氧化铈光催化性能的潜在且简单的方法之一，其中稀土元素掺杂的二氧化铈纳米棒（CeO-RE NRs）有望成为具有高活性的有前途的光催化剂。但是最佳掺杂条件，包括稀土元素的种类和浓度尚不明确，并且掺杂的稀土离子对光催化活性增强的贡献需要进一步研究。在这项工作中，我们将0%-30%范围内的La、Y和Sm掺杂到CeO纳米棒中，并研究了不同掺杂条件下的相、形态、带隙、氧空位浓度、PL光谱和光催化活性变化。除了15%和30% Y掺杂的样品外，所有合成的CeO-RE NRs都具有良好的纳米棒形态。合成样品的能带隙略有变化；带隙最窄的10% CeO-RE NRs具有较高的光催化性能。发现最出色的光催化剂是10% Y掺杂的CeO纳米棒，其亚甲基蓝光降解率为85.59%，速率常数为0.0134 min，这尤其与显著更高的氧空位浓度和明显更低的光生电子/空穴对复合率有关。掺杂的稀土离子和氧空位生成的促进阻碍了光生载流子的复合，这被认为是增强CeO光催化性能的主要原因。
