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
A new all-solid-state carbonate ion-selective electrode was fabricated via electrochemical and ion-exchange reactions with Ag nanoparticles and Ag2CO3-BaCO3 as ion-to-electron transducer and ion-selective layer, respe...A new all-solid-state carbonate ion-selective electrode was fabricated via electrochemical and ion-exchange reactions with Ag nanoparticles and Ag2CO3-BaCO3 as ion-to-electron transducer and ion-selective layer, respectively. This paper presented the detailed procedures of the construction of the electrode, the applications of the electrode in various experiments, and the corresponding chemical reaction principles involved. The fabricated electrode was characterized by means of scanning electron microscopy（SEM）, energy dispersive spectrometer（EDS）, and electrochemical analyses. The electrode exhibited stable linear responses to carbonate anions（10-5--10-1 mol/L） with average Slope of the curve being -26.56 mV per decade, and showed negligible responses to NO3, SO2-, and Sal- anions. The electrode was further used to measure the concentration of carbonate anions in boiler water. The measured concentration was lower than that determined via titration. Overall, the electrode exhibited the advantages of miniaturized size, robust construction, and compatibility with other equipment and thus could be ideally integrated into various sensor platforms to collect chemical data from industrial heat exchangers.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.
文摘A new all-solid-state carbonate ion-selective electrode was fabricated via electrochemical and ion-exchange reactions with Ag nanoparticles and Ag2CO3-BaCO3 as ion-to-electron transducer and ion-selective layer, respectively. This paper presented the detailed procedures of the construction of the electrode, the applications of the electrode in various experiments, and the corresponding chemical reaction principles involved. The fabricated electrode was characterized by means of scanning electron microscopy（SEM）, energy dispersive spectrometer（EDS）, and electrochemical analyses. The electrode exhibited stable linear responses to carbonate anions（10-5--10-1 mol/L） with average Slope of the curve being -26.56 mV per decade, and showed negligible responses to NO3, SO2-, and Sal- anions. The electrode was further used to measure the concentration of carbonate anions in boiler water. The measured concentration was lower than that determined via titration. Overall, the electrode exhibited the advantages of miniaturized size, robust construction, and compatibility with other equipment and thus could be ideally integrated into various sensor platforms to collect chemical data from industrial heat exchangers.
