Realizing nitrogen reduction reaction(NRR) to synthesis NH_3 under mild conditions has gained extensive attention as a promising alternative way to the energy-and emission-intensive Haber-Bosch process.Among varieties of potential strategies,photoelectrochemical(PEC) NRR exhibits many advantages including utilization of solar energy,water(H_2O) as the hydrogen source and ambient operation conditions.Herein,we have designed a solar-driven PEC-NRR system integrating high-efficiency Fe_2O_3-based photoanode and atomically dispersed cobalt(Co) cathode for ambient NH_3 synthesis.Using such solar-driven PEC-NRR system,high-efficiency Fe_2O_3-based photoanode is responsible for H_2O/OH oxidatio n,and meanwhile the generated photoelectrons transfer to the single-atom Co cathode for the N_2 reduction to NH_3.As a result,this system can afford an NH_3 yield rate of 1021.5 μg mgco~(-1) h~(-1) and a faradic efficiency of 11.9% at an applied potential bias of 1.2 V(versus reversible hydrogen electrode) on photoanode in 0.2 mol/L NaOH electrolyte under simulated sunlight irradiation. 相似文献
Electrosynthesis of NH3 through the N2 reduction reaction (NRR) under ambient conditions is regarded as promising technology to replace the industrial energy- and capital-intensive Haber–Bosch process. Herein, a room-temperature spontaneous redox approach to fabricate a core–shell-structured Au@CeO2 composite, with Au nanoparticle sizes below about 10 nm and a loading amount of 3.6 wt %, is reported for the NRR. The results demonstrate that as-synthesized Au@CeO2 possesses a surface area of 40.7 m2 g−1 and a porous structure. As an electrocatalyst, it exhibits high NRR activity, with an NH3 yield rate of 28.2 μg h−1 cm−2 (10.6 μg h−1 mg−1cat., 293.8 μg h−1 mg−1Au) and a faradaic efficiency of 9.50 % at −0.4 V versus a reversible hydrogen electrode in 0.01 m H2SO4 electrolyte. The characterization results reveal the presence of rich oxygen vacancies in the CeO2 nanoparticle shell of Au@CeO2; these are favorable for N2 adsorption and activation for the NRR. This has been further verified by theoretical calculations. The abundant oxygen vacancies in the CeO2 nanoparticle shell, combined with the Au nanoparticle core of Au@CeO2, are electrocatalytically active sites for the NRR, and thus, synergistically enhance the conversion of N2 into NH3. 相似文献
In this paper, the properties of the solutions ot Boltzmann-Poisson system in three dimensions are considered. The estimates of the energies (the kinetic and the potential energies) and the γ-th moments with γ∈[2,3) are obtained. The latter answers an open problem. 相似文献
Ultra-high molecular weight polyethylene (UHMWPE) fibrous adsorbents with different molar content of amidoxime (MAO) and acrylic acid (MAA) were prepared by graft polymerization of acrylonitrile (AN) and acrylic acid (AA), followed by amidoximation. Uranium adsorption experiments in both artificial and natural seawater were carried out to investigate the effect of MAO and MAA on the uranium adsorption capacity of UHMWPE fibrous adsorbents. Adsorption results showed that the UHMWPE fibrous adsorbent with MAO = 4.27 and MAA = 4.64 mmol/g-ads exhibited better uranium adsorption capacity in both artificial (7.01 mg-U/g-ads) and natural (0.77 mg-U/g-ads) seawater.