Microwave-Assisted Synthesis of a Stainless Steel Mesh-Supported Co₃O₄ Microrod Array As a Highly Efficient Catalyst for Electrochemical Water Oxidation

Abstract

With the rising energy crisis and increasingly serious environmental issues, clean energy sources like fuel cell and lithium–air batteries are attracting the attention of the whole world. The direct fuel cell, especially, is believed to be the quintessential replacement for conventional sources of energy because of its high energy conversion capacity. Electrochemical water splitting has an important role in such sustainable energy technologies. Catalysts play a worthwhile role in water splitting, especially the oxygen evolution reaction (OER). Engineering fine micro/nanostructures with subtle morphologies represents an effective strategy to enhance the activity of the resultant catalyst toward OER through exposing abundant electrochemically active sites. So, here we report a Co3O4@SUS catalyst, the well-defined Co3O4 microrods were successfully anchored onto the stainless steel mesh substrate with the assistance of diethylene­triamine using microwave irradiation, utilizing a commercially available microwave instrument. Co3O4@SUS possesses outstanding catalytic activity toward water oxidation. In water oxidation, the current density of 10 mA cm–2 was achieved at 298 mV overpotential with a low Tafel slope of 105 mV dec–1. In addition to low overpotential, Co3O4@SUS was stable under conditions of continuous O2 evolution for an extended period (24 h). The results show a highly efficient, scalable, and low-cost method for developing highly active and stable OER electrocatalysts in alkaline solution.

Preparative History vs Driving Force in Water Oxidation Catalysis: Parameter Space Studies of Cobalt Spinels

“…49 Additionally, a wide range of different synthetic methods was applied on Co 3 O 4 in the course of individual studies, including molten salt (MS), 50 ball milling (BM), 51 sol–gel (SG), 52 thermal decomposition (TD), 53,54 precipitation, 55 and classic/microwave hydrothermal (MW) synthesis. 56,57,21…”

Synthesis of ultrathin Co2AlO4 nanosheets with oxygen vacancies for enhanced electrocatalytic oxygen evolution

“…. ARTICLES (Table S1) [27,33,[41][42][43][44][45][46][47][48][49][50][51][52][53][54][55]. The results indicated that the VO-rich Co 2 AlO 4 possessed a high OER kinetics.…”

Supported nanocatalysts: recent developments in microwave synthesis for application in heterogeneous catalysis

“…4). 165 For comparison, Co 31 to support CoMo catalyst. 185 The 20Ti-SBA-15 (Si/Ti molar ratio 20) was prepared via hydrolysis and aging in MW reactor from TEOS and TTIP in presence of Pluronic P123 structure directing agent.…”

“…Fair number of attempts have also been made to prepare supported simple metal oxide (CoO x , Co 3 O 4 , NiO, Fe 3 O 4 , SnO 2 , CeO 2 , TiO 2 ) nanocatalysts for application in petrochemical industry. 75,[160][161][162][163][164][165][166] In order to improve the catalytic activity as well as versatility in application potential of simple metal or metal oxide nanocatalysts, investigations on supported bimetal, [171][172][173][174][175][177][178][179][180][181][182][183][184][185][186][187] mixed metal oxide [188][189][190][191][192][193]196,197 and ternary metal 198,199 nanocatalysts are also available. MW assisted synthesis has been claimed to be economically viable short green method to produce supported nanocatalyst.…”