Preparation of Ag0 Nanoparticles by EDM Method as Catalysts for Oxygen Reduction

Abstract

At present, platinum-based catalysts are the best cathode catalysts, but due to their high prices, they are difficult to use widely. Under alkaline conditions, silver is a better low-cost substitute. Here, a physical preparation method—electrical discharge machining (EDM)—is used to prepare Ag0 nanoparticles. The method is simple and has a high yield. The diameter of prepared nanoparticles is about 30 nm and the nanoparticle surface is rich in defects. These defects enhance the adsorption of O2. In addition, defects can cause tensile strain on the silver catalyst, causing the d-band center of silver to move upward. The defects and the upward shift of the d-band center jointly improve the adsorption energy and catalytic performance of Ag0. This work provides a new method for the engineering construction of surface defects and the preparation of metal catalysts.

Advances and insights in amorphous electrocatalyst towards water splitting

“…A high voltage will be passed between the two electrodes, and when the electric field strength is greater than the dielectric strength of the dielectric, the electrons emitted from the cathode collide rapidly with the neutral atoms of the anode, forming a high-temperature ion channel to vaporize the alloy, followed by rapid cooling and quenching in the liquid to form amorphous superfine particles. Guo et al [85] fixed the silver electrode in a conductive iron container connected to the EDM machine. Then, the coolant is poured, and the distance between the two electrodes is adjusted.…”

Copper Nanoparticles with Abundant Defects as a pH-Universal Catalyst for Hydrogen Evolution Reaction

“…Electric discharge in liquid (EDL) is a common process to remove material from the surface of a working piece. When a pulse voltage is applied on two metal electrodes, the liquid medium filled in the electrodes is broken through, leading to the formation of a discharge channel and high temperature plasma (∼7000 K). , The plasma heats the metal electrodes into vapor or metal droplets which are then quenched into metal nanoparticles by the liquid medium after the electrical pulse . Therefore, EDL tends to introduce defects in metal nanoparticles through the quenching effect.…”

Electrochemical Determination of Nanoparticle Size: Combined Theoretical and Experimental Study for Matrixless Silver Nanoparticles

“…The sample is called a nanomaterial when at least one of its dimensions is smaller than 100 nm. Nowadays, metal nanoparticles of nanoscale size in all three dimensions are broadly examined as very promising substances in technology [1], catalysis [2], environmental science [3], and medicine [4]. Silver nanoparticles (AgNPs) in aqueous solutions, because of their antimicrobial activity [5][6][7][8][9], can be used as pharmaceutical preparations or in agriculture as biostimulants to ease plants' growth [5,10,11].…”