Liangliang Huang,Tao Peng,Rui Wang,Beibei He,Jun Jin,Huanwen Wang,Yansheng Gong
Photocatalytic ammonia production holds immense promise as an environmentally sustainable approach to nitrogen fixation. In this study, In2O3/In2S3-ZnCdS ternary heterostructures were successfully constructed through an innovative in situ anion exchange process, coupled with a low-temperature hydrothermal method for ZnCdS (ZCS) incorporation. The resulting In2O3/In2S3-ZCS photocatalyst was proved to be highly efficient in converting N2 to NH3 under mild conditions, eliminating the need for sacrificial agents or precious metal catalysts. Notably, the NH4+ yield of In2O3/In2S3-0.5ZCS reached a significant level of 71.2 μmol g−1 h−1, which was 10.47 times higher than that of In2O3 (6.8 μmol g−1 h−1) and 3.22 times higher than that of In2O3/In2S3 (22.1 μmol g−1 h−1). This outstanding performance can be attributed to the ternary heterojunction configuration, which significantly extends the lifetime of photogenerated carriers and enhances the spatial separation of electrons and holes. The synergistic interplay between CdZnS, In2S3, and In2O3 in the heterojunction facilitates electron transport, thereby boosting the rate of the photocatalytic nitrogen fixation reaction. Our study not only validates the efficacy of ternary heterojunctions in photocatalytic nitrogen fixation but also offers valuable insights for the design and construction of such catalysts for future applications.
Honghong Yi,Ruzhu Jia,Xiaolong Tang,Dongjuan Kang,Qingjun Yu,Fengyu Gao,Shunzheng Zhao,Yunpeng Liu
Electrocatalyst reduction of nitrogen oxides (NOx) in the industrial flue gas to synthesize NH3 can not only greatly improve the electrochemical efficiency of NH3 production, but also realize the emission reduction and resource utilization of air pollutants. Purposeful structural optimization of catalysts is a key research challenge in this field. Firstly, density functional theory (DFT) calculations found that the formation of surface oxygen vacancies could be promoted by constructing metal cation vacancies on the catalyst surface, which in turn optimized the NO adsorption configuration and improved the catalytic activity. By this guidance, CoAl layered double hydroxides (CoAl-LDH) nanosheets containing Al atomic vacancies were prepared by alkali etching. Experimental results show that a suitable alkali etching time with aqueous NaOH can significantly enhance the electrocatalytic activity of the CoAl-LDH nanosheets for NO reduction to NH3. Compared with pristine CoAl-LDH (0.097 mg cm-2 h-1), the NH3 yield rate reached 0.310 mg cm-2 h-1 at -1.1 V vs. the reversible hydrogen electrode after alkali etching for 4 h, which increased by 2.2 times. The catalyst characterization and theoretical calculation results indicate that the abundant frustrated Lewis pairs (FLPs) on the surface of catalysts containing cation vacancies are the origin of the enhanced activity.