第一作者：大连理工大学 Muhammad Irfan Ahmad, Yanming Liu
通讯作者：大连理工大学 全燮
DOI：https://doi.org/10.1002/anie.202419628
光催化CO2和N2共还原是一种在温和条件下可持续合成尿素的方法。然而，由于C-N偶联反应动力学缓慢，高收率合成尿素是一个挑战。作者成功地设计了一种Z-scheme光催化剂SrTiO3-FeS-CoWO4，通过增强初始CO2和N2吸附步骤和降低C-N偶联反应的能量垒来促进光催化尿素合成。SrTiO3-FeS-CoWO4的尿素产率达到8054.2 μg·gcat−1·h-1，显著高于现有的尿素产率。FeS加速电荷转移的SrTiO3-FeS-CoWO4Z-scheme光催化剂不仅具有化学吸附和活化CO2和N2的双活性位点，而且还保留了高导带（-1.50 eV）和加速的电子和质子供应，这是其具有良好的光还原活性和显著降低C-N偶联反应速率决定步骤能量势垒的原因。
Fig. 1 Structure characterization. (a) SEM image of SrTiO3-FeS-CoWO4; The TEM images of (c-e) HRTEM images of SrTiO3-FeSCoWO4; (f-h) XPS spectra of SrTiO3-FeS-CoWO4; (i) XRD pattern
Fig. 2 Optical characterization. (a) UV-vis DRS spectra; (b) Energy band diagram of SrTiO3-FeS-CoWO4 Z-scheme heterojunctions. (c) Steady-state PL spectra of SrTiO3, SrTiO3-CoWO4, and SrTiO3-FeS-CoWO4; (d-e) TA spectra recorded on nanosecond timescale of SrTiO3-FeS-CoWO4, and the corresponding TA kinetic traces at 266 nm (f-g) TA spectra recorded on microsecond timescale of SrTiO3-FeS-CoWO4, and the corresponding TA kinetic traces at 520 nm. The excitation wavelength is 460 nm; EPR spectra for (h) •OH and (1) •O2− radicals.
Fig. 3 Photocatalytic urea synthesis. Urea yields of SrTiO3-FeS-CoWO4 with different (a) catalyst dosages and (b) gas flow rates; (c) 1HNMR spectra of urea produced with 15N2-CO2; (d) mass spectra of urea obtained from 13CO2-14N2 and 12CO2-14N2-15N2; (e) The urea yields on different catalysts; (f) the comparison of urea yields between SrTiO3-FeS-CoWO4 and the catalysts reported.
Fig. 4 Activity analysis. (a) Photocurrent response of pure and heterojunctions; CO2 or N2 solo adsorption and co-adsorption energies for (b) SrTiO3 and CoWO4, (c) SrTiO3-FeS-CoWO4 and (d) SrTiO3-CoWO4; (e) CO2-TPD and (f) N2-TPD curves of SrTiO3-FeS-CoWO4 from TPD-MS.
Fig. 5 Activity analysis. (a, b) Time-dependent in situ FTIR spectra of SrTiO3-FeS-CoWO4, (c) Free energy diagram of N2 adsorption with and without FeS. The corresponding geometry structures without (c) and with (d) adsorbed N2 with FeS.; (e) Gibbs free energy diagram of *NNH and *NCON intermediates. (f) Gibbs free energy diagram of urea produced on SrTiO3, CoWO4, SrTiO3- CoWO4, and SrTiO3-FeS-CoWO4
Enhanced photocatalytic synthesis of urea from co-reduction of N2 and CO2 on Z-schematic SrTiO3-FeS-CoWO4 heterostructure
https://doi.org/10.1002/anie.202419628
