具有电子调制平面异质结的金属有机骨架纳米片用于高电流密度全解水

Engineering metal-organic framework nanosheets with electronically modulated in-plane heterojunctions for robust high-current-density water splitting

设计基于界面工程的氧/氢析出反应(OER/HER)双功能电催化剂对在高电流密度下同时实现低过电位和稳定的水分解操作至关重要.本文中,我们报告了一种硼化策略以巧妙地定制固定在泡沫铁(IF)上的金属有机框架(MOF).硼原子诱导了Fe-MOF纳米片的结构重构,包括粗糙表面、氧空位以及结晶Fe-MOF和非晶Fe–B之间的面内异质结.面内异质结调节铁位点的d带中心以降低OER/HER能垒.优化的Fe–B/FeMOF/IF在10 m A cm^(-2)下驱动OER和全解水,分别仅需1.44和1.53 V.水分解系统在500 m A cm^(-2)下工作100小时以后的结构变化和性能衰减可忽略不计.该工作为异质结构界面的工程提供了启示,并促进了先进电催化剂的合理设计.

To simultaneously achieve low overpotentials and stable operation for water splitting at high current densities,bifunctional electrocatalysts must be designed based on interfacial engineering for the oxygen/hydrogen evolution reaction(OER/HER).Herein,we report a boronization tactic to ingeniously tailor metal-organic frameworks(MOFs)anchored on iron foam(IF).The boron atoms induce the structural reconstitution of the Fe-MOF nanosheets,including the surface roughness,oxygen vacancies,and in-plane heterojunctions between crystalline Fe-MOF and amorphous Fe–B.The in-plane heterojunctions modulate the d-band center of the Fe sites to reduce the energy barrier of the OER/HER.As expected,the optimized Fe–B/Fe-MOF/IF only needed 1.44 and 1.53 V at 10 m A cm^(-2)to drive the OER and overall water splitting,respectively.The water-splitting system served at 500 m A cm^(-2)for 100 h with negligible structure variation and performance degradation.This work sheds light on the engineering of heterostructure interfaces and promotes the rational design of advanced electrocatalysts.