One-Pot Formation of an rGO-Based ZnAl₂O₄ Nanocomposite for Electrochemical Studies toward Oxygen Evolution Reactions

Abstract

Electrocatalysts for water (H 2 O) splitting to give oxygen (O 2 ) and hydrogen (H 2 ) fuels are challenging to build, but mixing carbon materials with transition-metal-based compounds offers an intriguing and innovative method for the development of environment-friendly fuel. Hydrothermal synthesis is a cheap and effective catalyst based on a ZnAl 2 O 4 nanocomposite anchored over reduced graphene oxide (rGO) and is presented here, along with characterization by microscopy and spectroscopy. As a possible oxygen evolution reaction (OER) electrocatalyst on nickel foam's surface (NF), the electrochemical properties of this catalyst were also studied. The electrochemical studies showed that the ZnAl 2 O 4 anchored on rGO sample exhibited high stability for the OER and an enhanced surface area, ionic conductivity, and active zones of the electrocatalyst was observed compared to that of the other investigated composites. It also exhibited an overpotential of 244 mV achieved at 10 mA cm −2 and lowered solution resistance (R s = 0.63 Ω) and charge transfer resistance (R ct = 0.6 Ω). This catalyst has a wide operating current range and, therefore, may function for long periods of time at both high and low current densities. High electrical conductivity, a larger surface area, and enriched active zones are responsible for enhancing the ZnAl 2 O 4 @ rGO composite's multifunctional qualities, as shown by the results. The electrocatalytic properties of ZnAl 2 O 4 @rGO composites were enhanced, and they exhibited a high cycling stability of 50 h even after the 5000th cycle due to the combined influence of these surface features. The present investigation has revealed that the ZnAl 2 O 4 @rGO nanocomposite demonstrates significant versatility, making it highly suitable for various fields related to sustainable and renewable energy. This suggests that it could be employed in developing an efficient and promising electrode for the OER, thereby paving the way for new possibilities.

Accelerating materials discovery for electrocatalytic water oxidation via center-environment deep learning in spinel oxides

“…When the thermodynamic OER potential ( E [H 2 O/O 2 ] = 1.23 V) is used as the reference, the MoAg 2 O 4 electrode shows a very low overpotential of 284 mV at 10 mA cm −2 , which is considerably lower than those of MoNa 2 O 4 (339 mV), ZnAl 2 O 4 (352 mV) and commercial catalyst RuO 2 (323 mV). The overpotential of ZnAl 2 O 4 (352 mV) is very close to the reported result of 362 mV in the literature, 65 strongly supporting the reliability of our high-throughput screening results. Tafel plots of various catalysts extracted from LSV curves are illustrated in Fig.…”

“…Additionally, ZnAl 2 O 4 has been experimentally proven to possess good OER catalytic activity. 65 Our decision is further supported by the experimental evidence suggesting that ZnAl 2 O 4 exhibits commendable OER catalytic activity. 65 Therefore, our research will primarily focus on the MoAg 2 O 4 and MoNa 2 O 4 structures, aligning with both safety and efficacy considerations.…”

“…65 Our decision is further supported by the experimental evidence suggesting that ZnAl 2 O 4 exhibits commendable OER catalytic activity. 65 Therefore, our research will primarily focus on the MoAg 2 O 4 and MoNa 2 O 4 structures, aligning with both safety and efficacy considerations. Furthermore, as a validation of the high-throughput screening framework, we synthesized ZnAl 2 O 4 and tested its OER activity, comparing it with the performance reported in the literature.…”

Carbon-Based Composites for Oxygen Evolution Reaction Electrocatalysts: Design, Fabrication, and Application

“…The N doping of rGO further boosts OER performance [24]. Inspired by these results, researchers have performed many relevant works and made significant progress [25]. Common electrocatalysts for carbon-based OER materials include metal-free carbon or polymer-based materials, such as covalent organic frameworks (COFs) [26], porous organic polymers (POPs) [27], and composites of carbon and nonprecious metal-containing composite, such as CoP/carbon-cloth (CC), MCoP/CC [28], O-Co-N/C [29], and others [30].…”