Rutile TiO₂ Nanoparticles with Oxygen Vacancy for Photocatalytic Nitrogen Fixation

Abstract

Limited by the relatively low specific surface area and small quantity of active sites of semiconductor photocatalysts, the photocatalytic nitrogen fixation performance remains very low, as expected. Herein, rutile titanium dioxide (TiO2) nanoparticles with large specific surface area and abundant oxygen vacancy were designed for photocatalytic nitrogen fixation. The TiO2 photocatalysts exhibit high photocatalytic performance for nitrogen fixation in the presence of methanol as the hole scavenger, with the highest ammonia generation rate of 116 μmol·g–1·h–1, exceeding 6.5 times that of P25. This study provides a simple and facile method to prepare highly reactive TiO2 photocatalysts for enhanced photocatalytic nitrogen fixation performance.

Advanced Strategies for Improving the Photocatalytic Nitrogen Fixation Performance: A Short Review

“…From the introduction of vacancy defects on the surface of photocatalytic nitrogen fixation materials, unsaturated active sites can be constructed as trapping sites for photogenerated electrons or protons. Thus far, many studies have been reported on zinc vacancies, nitrogen vacancies, carbon vacancies, sulfur vacancies, and oxygen vacancies, ,,− in which oxygen vacancies (OVs) with abundant localized electrons occupy a pivotal position. Jin et al used the ultrathin structure of BiOBr ultrathin nanosheets to introduce more OVs to prepare V O -BiOBr, thus improving the photocatalytic nitrogen fixation performance (10 times that of BiOBr nanosheets), and explored the steps of the photocatalytic nitrogen fixation reaction based on OVs, dividing the reaction process into four steps (Figure a).…”

Research Progress and Perspectives on Active Sites of Photo- and Electrocatalytic Nitrogen Reduction

“…However, its activity is restricted by the low light utilization, high photogenerated carrier recombination, and limited active sites. As one of the most important defects, oxygen vacancies can efficiently improve the NRR activity of TiO 2 . ,− Liao et al immobilized Ti 3 C 2 MXene on P25, which introduced abundant oxygen vacancies into P25. DFT calculations (Figure a and b) demonstrated that OV-TiO 2 presented a longer NN bond and shorter Ti–N bonds compared to pristine TiO 2 , which confirmed that N 2 molecules were apt to be an adsorbed and activated layer on OV-TiO 2 .…”

Efficient sunlight promoted nitrogen fixation from air under room temperature and ambient pressure via Ti/Mo composites

“…The N≡N triple bond accepts the electrons provided by the oxygen vacancies and combines with the protons in the solution to form N-H bonds, which are finally converted into ammonia. [19,20] For example, He et al reported that indium sulfide nanotubes with more sulfur vacancies were prepared by calcining indium sulfide nanotubes to improve the photocatalytic nitrogen fixation effect. [21] Li and his group reported that the oxygen vacancy content increased and the photogenerated carrier separation and nitrogen adsorption capabilities of bismuth molybdate nanosheets were improved by etching bismuth molybdate with sodium hydroxide.…”