摘要：Electrochemical reduction from nitrate into ammonia is a chance for nitrate removal from drinking water,while at higher concentrations,this 8-electron reduction process could even become relevant for energy storage,high conversions and low onset potentials ***,we report the synthesis and analysis of a NiFe_(2)O_(4)/C-MS hybrid system made by a molten-salt strategy where the Ni-Fe oxide spinel nanoparticles act as the active center for electrochemical nitrate(NO_(3)−)reduction reaction,while the microporous carbon serves as a conductive support to form a cohesive electrode *** NiFe_(2)O_(4)/C-MS catalyst achieves a maximum NH3 yield rate of 5.4 mg mgcat.^(−1)h^(−1)and Faradaic efficiency of 98%at−0.6 V versus reversible hydrogen *** NiFe_(2)O_(4)nanoparticles buried into microporous carbon,the onset potential decreases *** propose that this reduction originates from charge redistribution in NiFe_(2)O_(4)in the electronic heterojunction with carbon,while enhanced electrolyte diffusion in microporous carbon facilitates high conversion *** functional theory calculations clarify the low energy barrier on NiFe_(2)O_(4),highlighting the essential role of Ni in activating Fe *** COMSOL Multiphysics simulations demonstrate that the microporous curled carbon accelerates NO_(3)−transport and enhances adsorption on the reactive *** work offers insights for designing carbon-based nanocomposites for efficient nitrate reduction electrocatalysis.

摘要：本文基于第一性原理系统研究了非金属元素F、S、Se、Te掺杂对ZnO/graphene异质结界面相互作用及其电子结构的影响。结果表明,ZnO/graphene异质结层间以范德瓦耳斯力结合形成了稳定的异质结,并且形成了n型肖特基势垒。差分电荷密度图表明graphene层的电子向ZnO层转移,使得graphene层表面带正电,ZnO层表面带负电,在界面处形成了内建电场。当掺入F原子时,异质结呈现欧姆接触;当掺入S、Se、Te原子时,异质结肖特基的接触类型均由n型转变为p型,且有效降低了肖特基势垒的高度,特别是Te原子掺入后,p型肖特基势垒高度降低至0.48 eV,提升了电子的注入效率。本文的研究结果将对相关的场效应晶体管的设计和制造提供一定的参考。