Synthesis And Screening Of Metal Oxide Electrocatalyst Through Ink-jet Printing Technology

Electrocatalysis has become a research hotspot due to its broad prospects in the field of developing clean energy and degrading pollutants,and it is the core task to develop electrocatalysts with high activity,high selectivity and high stability.Metal oxides with special physicochemical properties have been widely applied to various catalytic reactions,whose performance is supposed to be further improved through multi-component design.However,the current research on the catalytic mechanism is not enough to speculate the relationship between the composition as well as structure and performance of catalysts.Therefore,the development of new catalysts remains at the stage of repetitive material synthesis and performance testing.In order to promote the development of new metal oxide electrocatalysts,this paper innovatively combines ink-jet printing technology with scanning electrochemical microscopy to develop a high-throughput research scheme for combining and screening metal oxide electrocatalysts.The research of the thesis has the following results:1.Using metal nitrate solution as precursor,diethylene glycol and diethylene glycol monobutyl ether were added to adjust the viscosity,thereby preparing the ink suitable for preparing an oxide film by printing-The regular arrangement of metal oxide arrays was prepared by a modified piezoelectric color ink-jet printer.The sample is a dense metal oxide film,and its elements are uniformly distributed and the actual atomic ratio is substantially consistent with the designed value.The catalyst has significant oxygen evolution catalytic activity in a 1 mol/L KOH solution.The above conditions meet the requirements of high throughput screening of metal oxide electrocatalysts.2.The feedback mode of scanning electrochemical microscopy was used to characterize the OER catalytic activity of the microdomain of thin film materials.The tip was kept at the ORR potential,and a series of impulse-potential steps was applied to a catalytically active substrate electrode,which was switched between potentials where it displays OER activity and inactivity.Before each series of measurements,the tip was placed above the center of the sample to characterize the oxygen evolution catalytic activity of different samples by recording the amount of change in the oxygen reduction current of the tip.The accuracy of the scheme was verified by detecting the oxygen evolution catalytic performance of the single component sample.3.The high-throughput solution was used to screen the Fe-Co-Ni metal oxide sample library.The samples with the best OER catalytic activity among the three binary metal oxides were Ni60Co40,Co10Fe90 and Fe30Ni70,respectively.The sample with the best OER catalytic activity among the ternary metal oxides was Ni70Fe20Co10.