We present a fluorescent microscopic method using an ultra-pH-sensitive polymeric probe to rapidly map within subsecond the pH distribution resulting from oxygen reduction reaction electrocatalysed by an array of plat...We present a fluorescent microscopic method using an ultra-pH-sensitive polymeric probe to rapidly map within subsecond the pH distribution resulting from oxygen reduction reaction electrocatalysed by an array of platinum nanoparticles.Upon voltammetry of the surface-supported Pt catalysts,fluorescent quenching waves are observed to depend on the electrode potential.The spatiotemporal fluorescent evolution is then confirmed under a constant potential control to be due to the local pH change as a function of diffusing time by an estimation of the proton diffusion coefficientðLαt 1=2Þ.On these bases,the fluorescent measurements at short reaction times can provide quantitative information regarding the one and two dimensional pH distributions,which are shown to exhibit the expected shape of a typical diffusion-driven concentration gradient.Such imaging of proton/pH profiles may find important applications such as efficient screening of different micro/nanoscale electrocatalysts.展开更多
基金National Natural Science Foundation of China(21925403 and 21874070).
文摘We present a fluorescent microscopic method using an ultra-pH-sensitive polymeric probe to rapidly map within subsecond the pH distribution resulting from oxygen reduction reaction electrocatalysed by an array of platinum nanoparticles.Upon voltammetry of the surface-supported Pt catalysts,fluorescent quenching waves are observed to depend on the electrode potential.The spatiotemporal fluorescent evolution is then confirmed under a constant potential control to be due to the local pH change as a function of diffusing time by an estimation of the proton diffusion coefficientðLαt 1=2Þ.On these bases,the fluorescent measurements at short reaction times can provide quantitative information regarding the one and two dimensional pH distributions,which are shown to exhibit the expected shape of a typical diffusion-driven concentration gradient.Such imaging of proton/pH profiles may find important applications such as efficient screening of different micro/nanoscale electrocatalysts.
