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.
Photocatalytic N 2 fixation has attracted substantial attention in
recent years, as it represents a green and sustainable development route toward
efficiently converting N 2 to NH 3 for industrial
applications. How to rationally design catalysts in this regard remains a
challenge. Here we propose a strategy that uses plasmonic hot electrons in the
highly doped TiO 2 to activate the inert N 2 molecules. The
synthesized semiconductor catalyst Mo-doped TiO 2 shows a
NH 3 production efficiency as high as 134
µmol · g −1 · h −1 under
ambient conditions, which is comparable to that achieved by the conventional
plasmonic gold metal. By means of ultra-fast spectroscopy we reveal that the
plasmonic hot electrons in the system are responsible for the activation of
N 2 molecules, enabling improvement the catalytic activity of
TiO 2 . This work opens a new avenue toward semiconductor
plasmon-based photocatalytic N 2 fixation.
Photocatalytic fixation of nitrogen from air at normal temperature and pressure (NTP) is a fascinating topic for sustainable development and environment. A new type of organic ligand doped cobalt-iron oxides photocatalyst was designed and prepared which can inhibit the recombination of photoelectron-hole pairs and adjust the energy gap for converting nitrogen into ammonium at NTP. Its relevant properties and characterization data was examined by XRD, SEM, HRTEM, XPS, ESR, and UV-vis. These experimental data proved its nitrogen fixation ability. The rate of nitrogen fixation could be 216 μmol•L −1 •h −1 with simulated sunlight illumination. Moreover, this nitrogen fixation activity can also happen at night with the rate of 112μmol•L −1 •h −1 . This all-day nitrogen fixation ability makes it has the industrial potential application in future.
Li Cui,Kai Yang,Hong-Zhe Li,Han Zhang,Jian-Qiang Su,Maria Paraskevaidi,Francis L. Martin,Bin Ren,Yong-Guan Zhu
Nitrogen (N) fixation is the conversion of inert nitrogen gas (N2) to bioavailable N essential for all forms of life. N2-fixing microorganisms (diazotrophs), which play a key role in global N cycling, remain largely obscure because a large majority are uncultured. Direct probing of active diazotrophs in the environment is still a major challenge. Herein, a novel culture-independent single-cell approach combining resonance Raman (RR) spectroscopy with 15N2 stable isotope probing (SIP) was developed to discern N2-fixing bacteria in a complex soil community. Strong RR signals of cytochrome c (Cyt c, frequently present in diverse N2-fixing bacteria), along with a marked 15N2-induced Cyt c band shift, generated a highly distinguishable biomarker for N2 fixation. 15N2-induced shift was consistent well with 15N abundance in cell determined by isotope ratio mass spectroscopy. By applying this biomarker and Raman imaging, N2-fixing bacteria in both artificial and complex soil communities were discerned and imaged at the single–cell level. The linear band shift of Cyt c versus 15N2 percentage allowed quantification of N2 fixation extent of diverse soil bacteria. This single-cell approach will advance the exploration of hitherto uncultured diazotrophs in diverse ecosystems.