Resulting from the rising levels of atmospheric carbon, ocean acidification has become a global problem. It has significant impacts on the development, survival, growth and physiology of marine organisms. Therefore, a...Resulting from the rising levels of atmospheric carbon, ocean acidification has become a global problem. It has significant impacts on the development, survival, growth and physiology of marine organisms. Therefore, a high- precision sensor is urgently needed to measure the pH of sea-water. Iridium wire with a diameter of 0.25 mm is used as the substrate, and an Ir/Ir（OH）x pH electrode is prepared by a one-step electrochemical method in a LiOH solution at the room temperature. A scanning electron microscope （SEM） observation reveals that it is coated with nanoscale particles. In laboratory tests, the electrode exhibits a very promising pH response, with an ideal Nernst slope （56.14-59.52）, fast response, good stability and long fife-span in tested pH buffer solutions. For a sea trial, four pH electrodes and one Ag/AgC1 reference electrode are integrated with a self-made chemical sensor, and a profile detection of nearly 70 m is implemented near Newport Harbor, California on August 3, 2015. The results reflect that the pH value measured by the sensor is very close to the data given by Sea-Bird 911 plus CTD, with a difference value ranging from 0.000 075 to 0.064 719. And the sensor shows a better data matching degree in 0-40 m water depth. In addition, the high precision and accuracy of the sensor make it possible to use in the ocean observation field.展开更多
An effective oxygen evolution electrode with Ir0.6Sn0.4O2 was designed for proton exchange membrane(PEM)water electrolyzers.The anode catalyst layer exhibits a jagged structure with smaller particles and pores,which p...An effective oxygen evolution electrode with Ir0.6Sn0.4O2 was designed for proton exchange membrane(PEM)water electrolyzers.The anode catalyst layer exhibits a jagged structure with smaller particles and pores,which provide more active sites and mass transportation channels.The prepared IrSn electrode showed a cell voltage of 1.96 V at 2.0 A cm^-2 with Ir loading as low as 0.294 mg cm^-2.Furthermore,Ir Sn electrode with different anode catalyst loadings was investigated.The IrS n electrode indicates higher mass current and more stable cell voltage than the commercial Ir Black electrode at low loading.展开更多
A novel design of IR OTTLE is shown to have sufficient sensitivity and experi- mental simplicity for obtaining IR spectra of the species generated during electrochemical oxidation-reduction.
A novel idea of in-cell iR compensation was proposed by using a four-electrode electrochemical system, which was consisted of two working electrodes, one reference electrode （RE） and one auxiliary electrode （AE）. ...A novel idea of in-cell iR compensation was proposed by using a four-electrode electrochemical system, which was consisted of two working electrodes, one reference electrode （RE） and one auxiliary electrode （AE）. One of the two working electrodes was called the auxiliary working electrode （AWE）, which was directly connected to the ground. Another working electrode was used as a regular working electrode （WE） for electrochemical testing. The reference electrode was set in a frit close to the AWE for potential sampling. The other electrodes, WE, RE and AE, were connected to a conventional potentiostat of three-electrode system for electrochemical measurements. A linear narrow electrochemical cell was designed for setting AE at one end and AWE with RE at another end, and setting WE in between AE and AWE. In this way, a positive feedback potential was generated at the working electrode from the solution resistance and the current flow in the solution. An formal iR compensation over 100%, as high as 500%, had been achieved without potential oscillation. The electrochemical cell design, the principle of the in-cell iR compensation, and the preliminary voltammetric characterization by using the redox reaction of ferrocyanide anions were reported.展开更多
In situ scanning FTIR microscopy was built up for the first time in the present work, which consists of an FTIR apparatus, an IR microscope, an X-Y mapping stage, and the specially designed electrochemical IR cell and...In situ scanning FTIR microscopy was built up for the first time in the present work, which consists of an FTIR apparatus, an IR microscope, an X-Y mapping stage, and the specially designed electrochemical IR cell and computer software. It has been demonstrated that this new space-resolvd in situ IR technique can be used to study vibration properties of micro-area, and to perform IR imaging of electrode surface. The chemical image obtained using this technique fur CO adsorption on Pt electrode illustrated, at a space-resolution of 10<sup>-2</sup> cm, the inhomogeneity and the distribution of reactivity of micro-area of electrode surface.展开更多
基金The Key Laboratory Project of State Oceanic Administration for Marine Ecosystem and Biogeochemistry of China under contract No.529101-X21601the Foundation from Wendy Schmidt Ocean Health XPRIZE and the Southern California Coastal Water Research Project
文摘Resulting from the rising levels of atmospheric carbon, ocean acidification has become a global problem. It has significant impacts on the development, survival, growth and physiology of marine organisms. Therefore, a high- precision sensor is urgently needed to measure the pH of sea-water. Iridium wire with a diameter of 0.25 mm is used as the substrate, and an Ir/Ir（OH）x pH electrode is prepared by a one-step electrochemical method in a LiOH solution at the room temperature. A scanning electron microscope （SEM） observation reveals that it is coated with nanoscale particles. In laboratory tests, the electrode exhibits a very promising pH response, with an ideal Nernst slope （56.14-59.52）, fast response, good stability and long fife-span in tested pH buffer solutions. For a sea trial, four pH electrodes and one Ag/AgC1 reference electrode are integrated with a self-made chemical sensor, and a profile detection of nearly 70 m is implemented near Newport Harbor, California on August 3, 2015. The results reflect that the pH value measured by the sensor is very close to the data given by Sea-Bird 911 plus CTD, with a difference value ranging from 0.000 075 to 0.064 719. And the sensor shows a better data matching degree in 0-40 m water depth. In addition, the high precision and accuracy of the sensor make it possible to use in the ocean observation field.
基金financially supported by the National Natural Science Foundation of China(U1664259)State Grid Corporation of China(No.SGTYHT/15-JS-191,PEMWE MEA Preparation and degradation mechanism)
文摘An effective oxygen evolution electrode with Ir0.6Sn0.4O2 was designed for proton exchange membrane(PEM)water electrolyzers.The anode catalyst layer exhibits a jagged structure with smaller particles and pores,which provide more active sites and mass transportation channels.The prepared IrSn electrode showed a cell voltage of 1.96 V at 2.0 A cm^-2 with Ir loading as low as 0.294 mg cm^-2.Furthermore,Ir Sn electrode with different anode catalyst loadings was investigated.The IrS n electrode indicates higher mass current and more stable cell voltage than the commercial Ir Black electrode at low loading.
文摘A novel design of IR OTTLE is shown to have sufficient sensitivity and experi- mental simplicity for obtaining IR spectra of the species generated during electrochemical oxidation-reduction.
文摘A novel idea of in-cell iR compensation was proposed by using a four-electrode electrochemical system, which was consisted of two working electrodes, one reference electrode （RE） and one auxiliary electrode （AE）. One of the two working electrodes was called the auxiliary working electrode （AWE）, which was directly connected to the ground. Another working electrode was used as a regular working electrode （WE） for electrochemical testing. The reference electrode was set in a frit close to the AWE for potential sampling. The other electrodes, WE, RE and AE, were connected to a conventional potentiostat of three-electrode system for electrochemical measurements. A linear narrow electrochemical cell was designed for setting AE at one end and AWE with RE at another end, and setting WE in between AE and AWE. In this way, a positive feedback potential was generated at the working electrode from the solution resistance and the current flow in the solution. An formal iR compensation over 100%, as high as 500%, had been achieved without potential oscillation. The electrochemical cell design, the principle of the in-cell iR compensation, and the preliminary voltammetric characterization by using the redox reaction of ferrocyanide anions were reported.
基金Project supported by the National Natural Science Foundation of China (Grant No. 29525307)
文摘In situ scanning FTIR microscopy was built up for the first time in the present work, which consists of an FTIR apparatus, an IR microscope, an X-Y mapping stage, and the specially designed electrochemical IR cell and computer software. It has been demonstrated that this new space-resolvd in situ IR technique can be used to study vibration properties of micro-area, and to perform IR imaging of electrode surface. The chemical image obtained using this technique fur CO adsorption on Pt electrode illustrated, at a space-resolution of 10<sup>-2</sup> cm, the inhomogeneity and the distribution of reactivity of micro-area of electrode surface.
