Hydrogen peroxide electrogeneration in gas diffusion electrode nanostructured with Ta2O5

Abstract

a b s t r a c tHighly efficient H 2 O 2 electrogeneration is required in the Advanced Oxidation Process for organic wastewater treatment. However, the development of more efficient catalytic particles used in gas diffusion electrodes (GDEs) to enable the oxygen reduction reaction through two-electron transfer is still of great importance. The performance of the Ta 2 O 5 nanoparticles on carbon black in catalyzing the ORR was evaluated using rotating ring-disk electrode. The current efficiency for H 2 O 2 electrogeneration on Ta 2 O 5 /C catalyst is 83.2% whereas carbon black exhibits 65.3%. GDEs were constructed using carbon black either unmodified or modified with Ta 2 O 5 nanoparticles. The modified GDE produces 27.9 mg L −1 of H 2 O 2 , while the unmodified GDE generates 19.1 mg L −1 of H 2 O 2 . Furthermore, the energy consumption for the H 2 O 2 electrogeneration is lower in modified than in unmodified GDE (15.0 kW h vs. 18.8 kW h). The high performance of the GDE (Ta 2 O 5 /C) renders it a viable alternative cathode in the electrochemical treatment of wastewaters.

Highly efficient electrosynthesis of hydrogen peroxide on a superhydrophobic three-phase interface by natural air diffusion

“…Over the years, many researchers have focused on improving the catalytic layer of GDE to increase H 2 O 2 production, but little attention has been paid to improve O 2 mass transfer efficiency 14,[20][21][22] . Moreira et al prepared GDE modified with 0.5% Sudan Red 7B, obtaining 8.9 mg h −1 cm −2 of H 2 O 2 with a current efficiency of 17.87% when 0.3-bar O 2 was supplied at a current density of 75 mA cm −2 23 .…”

pH Transitions and electrochemical behavior during the synthesis of iron oxide nanoparticles with gas-diffusion electrodes

“…5,[10][11][12] The development of environmentally friendly synthesis methods has gained particular attention, [13][14][15][16][17] intensifying the interest in electrochemistry as a synthetic platform under mild conditions. [18][19][20][21][22][23][24][25] In most instances, known electrochemical approaches for the synthesis of nanoparticles [26][27][28] involve the growth of lms onto inert substrates, mostly by one-step electrodeposition, at working temperatures between 70 and 90 C. A compilation of pathways and methods for the electrochemical formation of magnetite nanoparticles is available in the scien-tic literature. 23,26,[29][30][31][32] In the present study, a new electrochemical method, called gas-diffusion electrocrystallization (GDEx), 14 is employed for the formation of iron oxide nanoparticles (IONPs) 33 from a soluble iron precursor (Fe 2+ ).…”

“…Throughout this work, both chemical species, i.e., H 2 O 2 and HO 2 À , will be referred to as H 2 O 2 , granting that at more alkaline pHs HO 2 À will be the most abundant species (pK a ¼ 11.65). 24,34 The effective dissolution of O 2 gas is the limiting step of this process, but with gas-diffusion electrodes this is overcome by the high mass transport rates at the triple-phase boundary. 35 The present work differs from previous electrochemical methods in various ways.…”

A Newly Competitive Electrochemical Sensor for Sensitive Determination of Chrysin Based on Electrochemically Activated Ta2O5 Particles Modified Carbon Paste Electrode

“…Tantalum oxide (Ta 2 O 5 ) is a stable transition metal oxide in most solutions . Ta 2 O 5 based C and N compounds exhibited electro‐catalytic activity for oxygen reduction reaction in polymer electrolyte fuel cells . Metal doped Ta 2 O 5 film also exhibited excellent electrochemical reversibility and good catalytic performance .…”