Li Chang, Gu MengZhen, Gao MingMing, Liu KeNing, Zhao XinYu, Cao NaiWen, Feng Jing, Ren YueMing, Wei Tong, Zhang MingYi
Key Laboratory of Superlight Materials & Surface Technology of Ministry of Education, Harbin Engineering University, Harbin 150001, PR China.
Key Laboratory of Superlight Materials & Surface Technology of Ministry of Education, Harbin Engineering University, Harbin 150001, PR China.
J Colloid Interface Sci. 2022 Mar;609:341-352. doi: 10.1016/j.jcis.2021.11.180. Epub 2021 Dec 2.
Photocatalytic fixation of nitrogen to ammonia (NH) is a green but low-efficiency technology due to the high recombination of photo-generated carriers and poor light absorption of photocatalysts. Generally, the adsorption capacity for N and the band position of TiO are responsible for bandgap, light-adsorption, and the separation of photocarriers. Therefore, they play crucial roles to improve catalytic activity. Herein, N-doping TiO hollow microspheres (NTO-0.5) with oxygen vacancies were synthesized via a hydrothermal method using phenolic resin microsphere as a template. The obtained NTO-0.5 achieves an impressive ammonia yield of 80.09 μmol gh. Oxygen vacancies of NTO-0.5 were confirmed by ESR, Raman, XPS, Zeta potential, and HO treatment for reducing oxygen vacancies. The ammonia yield of NTO-0.5 decreases to 34.78 μmol gh after reducing oxygen vacancies by HO treatment, which demonstrates the importance of oxygen vacancies. The oxygen vacancies narrow the bandgap from 3.18 eV to 2.83 eV and impede the recombination of photo-generated carriers. The hollow microspheres structure is conducive to light absorption and utilization. Therefore, the synergistic effect between the oxygen vacancies and the hollow microspheres structure boosts the efficiency of photocatalytic nitrogen fixation. After four cycles, the ammonia production yield still maintains at 76.52 μmol gh, meaning high stability. This work provides a new insight into the construction of catalysts with oxygen vacancies to enhance photocatalytic nitrogen fixation performance.
光催化固氮制氨是一项绿色但效率较低的技术，这是由于光生载流子的高复合率以及光催化剂较差的光吸收性能。一般来说，TiO对N的吸附能力和能带位置决定了带隙、光吸收以及光载流子的分离。因此，它们在提高催化活性方面起着关键作用。在此，以酚醛树脂微球为模板，通过水热法合成了具有氧空位的N掺杂TiO中空微球（NTO-0.5）。所制备的NTO-0.5实现了令人瞩目的80.09 μmol g h的氨产量。通过电子顺磁共振（ESR）、拉曼光谱、X射线光电子能谱（XPS）、zeta电位以及用于减少氧空位的HO处理，证实了NTO-0.5中的氧空位。经过HO处理减少氧空位后，NTO-0.5的氨产量降至34.78 μmol g h，这证明了氧空位的重要性。氧空位使带隙从3.18 eV缩小到2.83 eV，并阻碍光生载流子的复合。中空微球结构有利于光的吸收和利用。因此，氧空位与中空微球结构之间的协同效应提高了光催化固氮的效率。经过四个循环后，氨产量仍保持在76.52 μmol g h，意味着具有高稳定性。这项工作为构建具有氧空位的催化剂以提高光催化固氮性能提供了新的见解。
