事实证明,光催化将CO2还原为有价值的燃料是生产可再生能源和减少CO2排放的有利过程,这主要取决于设计具有快速电荷载流子分离速率的有效光催化剂。在这一贡献中,介孔n-n异质结Li2MnO3/WO3纳米复合材料是通过简单的溶胶-凝胶工艺设计的,用于利用可见光(λ>420nm)还原CO2。XRD和TEM测量证实合成的Li2MnO3/WO3纳米复合材料是单斜结构,其粒径为25±5nm。获得的Li2MnO3/WO3表现出较窄的带隙能量(1.74eV),更大的表面积(212m2g-1),非常可见的吸收,和较低的电子和空穴的复合。对于裸露的WO3和5%,CH3OH的产率确定为约198、871、1140、1550和1570mmol-1,10%,15%和20%Li2MnO3/WO3纳米复合材料,分别。这些结果表明,与其他纳米复合材料相比,15%的Li2MnO3/WO3光催化剂表现出最佳的还原能力。15%Li2MnO3/WO3光催化剂的CO2还原与大幅提升的CH3OH实现了最大的CO2转化率,即,1550mmolg-1后9小时,比WO3NP提高了7.8倍。介孔Li2MnO3/WO3纳米复合材料,与裸露的WO3NP相比,创造了更多的活性位点来促进CO2,并具有特定的电场来更有效地分离电荷载流子。Li2MnO3/WO3光催化剂在CO2持续还原45h时具有优越的光稳定性,且无明显下降。讨论了具有增强的CO2还原能力的Li2MnO3/WO3光催化剂上电子转移的可能直接S方案机理。本工作展示了在太阳能诱导的潜在应用中构建高效异质结构光催化剂的途径。
Photocatalytic CO2 reduction to valuable fuels has proved to be a favourable process to produce renewable energy and reduce CO2 emissions, which mostly depends on designing effective photocatalysts with the rapid separation rate of charge carriers. In this contribution, mesoporous n-n heterojunction Li2MnO3/WO3 nanocomposites were designed via a simplistic sol-gel process for CO2 reduction utilizing visible illumination (λ > 420 nm). XRD and TEM measurements confirmed the synthesized Li2MnO3/WO3 nanocomposite is a monoclinic structure, and its particle size is 25 ± 5 nm. The obtained Li2MnO3/WO3 exhibited narrower bandgap energy (1.74 eV), larger surface area (212 m2g-1), exceedingly visible absorbing, and lower recombination of electron and hole. The yield of CH3OH was determined about 198, 871, 1140, 1550 and 1570 mmolg-1 for bare WO3 and 5%, 10%, 15% and 20% Li2MnO3/WO3 nanocomposites, respectively. These results evidenced that the 15% Li2MnO3/WO3 photocatalyst exhibited the best reduction ability compared to other nanocomposites. The CO2 reduction over 15% Li2MnO3/WO3 photocatalyst achieved a maximal CO2 conversion with the substantially boosted CH3OH, i.e., 1550 mmolg-1 after 9 h, which was enhanced 7.8 folds great than of WO3 NPs. Mesoporous Li2MnO3/WO3 nanocomposites, in comparison with bare WO3 NPs, created more active sites for facilitating CO2 and had a specific electric field to more effectively separate charge carriers. The Li2MnO3/WO3 photocatalyst has superior photostability during the continuous reduction of CO2 for 45 h with no remarkable decrease. The possible direct S-scheme mechanism for electron transfer over Li2MnO3/WO3 photocatalyst with the enhanced CO2 reduction ability was discussed. The present work demonstrates an avenue for building highly effective heterostructure photocatalysts in solar-energy-induced potential applications.