Abstract
The development of efficient, stable, and non-precious metal water oxidation catalysts (WOCs) is a matter of importance for sustainable energy research. In this work, iron cobaltite (FeCo2O4) nanoparticles were prepared by the coprecipitation method, and we present the effect of heat treatment (250, 350, 450, 650 and 900 °C) on the catalytic properties. Catalytic activity tests of FeCo2O4 nanocatalysts were performed in the presence of ammonium cerium(IV) nitrate (CAN), and the formation of oxygen was followed using a Clark-type oxygen electrode. The samples were characterized by infrared (IR), thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and their surface areas were determined by the Brunauer, Emmett, and Teller (BET) method. Fourier transform infrared (FTIR) data confirm a metal-oxygen bond at the octahedral and tetrahedral sites. XRDs data were characteristic of spinel-like cubic materials. The XPS results confirmed the presence of trivalent and divalent cobalt and iron ions in the samples and showed that the non-heated sample has a greater amount of cobalt on the nanoparticles’ surface than those heated to 900 °C. The surface area decreased from 92.00 m2 g-1 for the material that was unannealed to 2.00 m2 g-1 for the sample annealed at 900 °C. The unannealed nanomaterials showed an oxygen production of 790 mmol s−1 g−1. This was 790 times greater than the oxygen production from nanomaterials heated to 900 °C. Although the surface structure of nanomaterials is unclear, the amount of surface cobalt appears to have implications for catalytic activity. Optimization of superficial cobalt content may be key to improving catalytic activity.
Highlights
The water splitting reaction is considered to be the most attractive method for generating hydrogen, which is the most versatile means of clean energy storage, including captured solar power.[1,2] the hydrogen produced can be used as a combustible for fuel cells generating electricity, and its final oxidation product is water
DTA curve of the sample showed a sharp exothermic peak centered at 475 °C, which corresponds to crystallization of ferrite, as observed on the X-ray diffraction (XRD) for samples heated above 650 °C (Figure 2)
The excess cobalt on the surface can be the reason for the higher catalytic activity observed for the unannealed solid
Summary
The water splitting reaction is considered to be the most attractive method for generating hydrogen, which is the most versatile means of clean energy storage, including captured solar power.[1,2] the hydrogen produced can be used as a combustible for fuel cells generating electricity, and its final oxidation product is water. The water-splitting reaction can be divided into two independent half-reactions: water oxidation and proton reduction, equations 1 and 2, respectively. Water splitting involves the removal of four protons and four electrons from two water molecules and.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
