文章信息/Info

Title:

Ruthenium Single Atoms Supported on Graphitic Carbon Nitride for Nitrogen Photofixation

文章編號(hào):

1674-3962(2021)03-0234-07

作者:

李　麗1; 2; 余　愿1; 孫東峰1; 許并社1

（1.陜西科技大學(xué) 材料原子分子科學(xué)研究所，陜西 西安 710021）（2.陜西科技大學(xué)材料科學(xué)與工程學(xué)院，陜西 西安 710021）

Author(s):

LI Li1; 2;  YU Yuan1;  SUN Dongfeng1;  XU Bingshe1

(1. Materials Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology, Xi’an 710021, China) (2. School of Materials Science & Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China.)

關(guān)鍵詞:

Ru單原子; g-C3N4; 氰基基團(tuán); 光催化固氮

Keywords:

Ru single atoms;  g-C3N4;  cyano groups;  nitrogen photofixation

分類號(hào):

O643.36;O644.1

DOI:

10.7502/j.issn.1674-3962.202102002

文獻(xiàn)標(biāo)志碼:

A

摘要:

采用固相原位還原法成功合成了負(fù)載釕（Ru）單原子的石墨相氮化碳（g-C3N4）催化劑。研究結(jié)果表明，Ru以單原子形式分散在g-C3N4材料表面上，Ru的負(fù)載使g-C3N4的3-s-三嗪?jiǎn)卧�結(jié)構(gòu)的有序度降低，通過(guò)傅里葉變換紅外吸收光譜（FTIR）測(cè)試分析可知催化劑中含有氰基，氰基導(dǎo)致了分子結(jié)構(gòu)缺陷。Ru和氰基均為電子受體，可加速光生電子的轉(zhuǎn)移并作為催化活性位點(diǎn)。負(fù)載Ru單原子后，g-C3N4的光吸收范圍變寬，光吸收強(qiáng)度增強(qiáng)，使得Ru單原子負(fù)載g-C3N4具有良好的光催化活性，光催化固氮效率高達(dá)113.23 μg·g-1cat·h-1，是單相g-C3N4催化劑的2.7倍。同時(shí)，Ru原子負(fù)載的g-C3N4還顯示出很好的穩(wěn)定性，經(jīng)5次循環(huán)實(shí)驗(yàn)后光催化固氮效率仍能維持在106.75 μg·g-1cat·h-1。此外，通過(guò)光致發(fā)光光譜（PL）、電化學(xué)阻抗譜（EIS）等表征手段探究了Ru單原子g-C3N4的光催化固氮機(jī)理，其中氮?dú)狻⒊�純水和光照是使催化劑發(fā)揮光催化固氮作用的必要條件。

Abstract:

A catalyst of graphitic carbon nitride (g-C3N4) loaded with ruthenium (Ru) single atoms was synthesized by the method of solid phase in-situ reduction successfully. The results showed that Ru was dispersed on the surface of g-C3N4 as single atoms, and the loading of Ru reduced in-plane repeating units of g-C3N4. Through the analysis of FTIR, it was found that there were cyano groups in the catalyst, which led to the molecular structural defect. Both Ru atoms and cyano groups were electron acceptors, which could accelerate the transfer of photogenerated electrons and acted as photocatalytic active sites. After loading with Ru atoms, the light absorption range of g-C3N4 was widened and the absorption intensity was enhanced. Thus, the catalyst had excellent activity. Its photocatalytic nitrogen fixation efficiency was as high as 113.23 μg·g-1cat·h-1, 2.7 times that of the bare g-C3N4 catalyst. Meanwhile, the catalyst of g-C3N4 supported by Ru atoms also showed good stability, and the photocatalytic nitrogen fixation efficiency remained at 106.75 μg·g-1cat·h-1 after five cycles. In addition, the photocatalytic nitrogen fixation mechanism of the catalyst was investigated by PL, EIS and other characterization methods, in which nitrogen, ultrapure water and illumination were necessary conditions for the photocatalytic nitrogen fixation of the catalyst.